研究者業績

岩田 仲生

イワタ ナカオ  (Nakao Iwata)

基本情報

所属
藤田医科大学 医学部 教授
学位
博士(医学)(名古屋大学)

J-GLOBAL ID
200901048638344557
researchmap会員ID
5000024641

外部リンク

1989年 名古屋大学医学部卒業
1993年 名古屋大学大学院修了 博士(医学)
1994年 名古屋大学医学部付属病院精神科 医員
1996年 National Institute of Health Visiting Fellow
1998年 藤田医科大学医学部精神神経科学 講師
2002年 藤田医科大学医学部精神神経科学 助教授
2003年 藤田医科大学医学部精神神経科学 教授(現職)
2011年 藤田医科大学研究支援推進本部 本部長(現職)
2015年 藤田医科大学医学部 医学部長(現職)
2016年 藤田医科大学 副学長(現職)
専門分野: 精神疾患の分子遺伝学、神経生化学、薬理遺伝学、臨床精神薬理学

学歴

 2

論文

 613
  • Daisuke Nishizawa, Shinya Kasai, Junko Hasegawa, Naomi Sato, Hidetaka Yamada, Fumihiko Tanioka, Makoto Nagashima, Ryoji Katoh, Yasuo Satoh, Megumi Tagami, Hiroshi Ujike, Norio Ozaki, Toshiya Inada, Nakao Iwata, Ichiro Sora, Masaomi Iyo, Mitsuhiko Yamada, Naoki Kondo, Moo-Jun Won, Nobuya Naruse, Kumi Uehara-Aoyama, Masanari Itokawa, Kazutaka Ohi, Ryota Hashimoto, Kumpei Tanisawa, Tomio Arai, Seijiro Mori, Motoji Sawabe, Makiko Naka-Mieno, Yoshiji Yamada, Miki Yamada, Noriko Sato, Masaaki Muramatsu, Masashi Tanaka, Yoko Irukayama-Tomobe, Yuki C Saito, Takeshi Sakurai, Masakazu Hayashida, Haruhiko Sugimura, Kazutaka Ikeda
    Molecular brain 8 50-50 2015年8月20日  査読有り
    BACKGROUND: Many genetic and environmental factors are involved in the etiology of nicotine dependence. Although several candidate gene variations have been reported by candidate gene studies or genome-wide association studies (GWASs) to be associated with smoking behavior and the vulnerability to nicotine dependence, such studies have been mostly conducted with subjects with European ancestry. However, genetic factors have rarely been investigated for the Japanese population as GWASs. To elucidate genetic factors involved in nicotine dependence in Japanese, the present study comprehensively explored genetic contributors to nicotine dependence by using whole-genome genotyping arrays with more than 200,000 markers in Japanese subjects. RESULTS: The subjects for the GWAS and replication study were 148 and 374 patients, respectively. A two-stage GWAS was conducted using the Fagerström Test for Nicotine Dependence (FTND), Tobacco Dependence Screener (TDS), and number of cigarettes smoked per day (CPD) as indices of nicotine dependence. For the additional association analyses, patients who underwent major abdominal surgery, patients with methamphetamine dependence/psychosis, and healthy subjects with schizotypal personality trait data were recruited. Autopsy specimens with various diseases were also evaluated. After the study of associations between more than 200,000 marker single-nucleotide polymorphisms (SNPs) and the FTND, TDS, and CPD, the nonsynonymous rs2653349 SNP (located on the gene that encodes orexin [hypocretin] receptor 2) was selected as the most notable SNP associated with FTND, with a p value of 0.0005921 in the two-stage GWAS. This possible association was replicated for the remaining 374 samples. This SNP was also associated with postoperative pain, the initiation of methamphetamine use, schizotypal personality traits, and susceptibility to goiter. CONCLUSIONS: Although the p value did not reach a conventional genome-wide level of significance in our two-stage GWAS, we obtained significant results in the subsequent analyses that suggest that the rs2653349 SNP (Val308Ile) could be a genetic factor that is related to nicotine dependence and possibly pain, schizotypal personality traits, and goiter in the Japanese population.
  • Atsushi Hirano, Tomoyuki Ohara, Atsushi Takahashi, Masayuki Aoki, Yuta Fuyuno, Kyota Ashikawa, Takashi Morihara, Masatoshi Takeda, Kouzin Kamino, Etsuko Oshima, Yuko Okahisa, Nobuto Shibata, Heii Arai, Hiroyasu Akatsu, Masashi Ikeda, Nakao Iwata, Toshiharu Ninomiya, Akira Monji, Takanari Kitazono, Yutaka Kiyohara, Michiaki Kubo, Shigenobu Kanba
    Psychiatric genetics 25(4) 139-46 2015年8月  査読有り
    OBJECTIVE: Although a number of genome-wide association studies (GWASs) of late-onset Alzheimer's disease (LOAD) have been carried out, there have been little GWAS data on East Asian populations. DESIGN: To discover the novel susceptibility loci of LOAD, we carried out a GWAS using 816 LOAD cases and 7992 controls with a replication analysis using an independent panel of 1011 LOAD cases and 7212 controls in a Japanese population. In addition, we carried out a stratified analysis by APOE-ε4 status to eliminate the established effect of APOE region. RESULTS: Our data indicated that 18p11.32 (rs1992269, P = 9.77 × 10(-7)), CNTNAP2 (rs802571, P = 1.26 × 10(-6)), and 12q24.23 (rs11613092, P = 6.85 × 10(-6)) were suggestive loci for susceptibility to LOAD. CONCLUSION: We identified three suggestive loci for susceptibility to LOAD in a Japanese population. Among these, rs802571, located at intron 1 of CNTNAP2, was considered to be a plausible candidate locus from a functional perspective.
  • Satoru Ide, Shingo Kakeda, Keita Watanabe, Reiji Yoshimura, Osamu Abe, Kenji Hayashi, Issei Ueda, Taro Kishi, Asuka Katsuki, Wakako Umene-Nakano, Nakao Iwata, Jun Nakamura, Yukunori Korogi
    PSYCHIATRY RESEARCH-NEUROIMAGING 233(2) 120-124 2015年8月  査読有り
    The brain-derived neurotrophic factor (BDNF) relates to basic neuronal functions, such as cell survival, axonal outgrowth, and dendritic growth. The Va166Met polymorphism of the BDNF gene may affect genetic susceptibility to major depressive disorder (MDD). We prospectively investigated the relationship between the Va166Met BDNF genotype and voxel-based morphometry (VB1V1) findings for first episode and drug-naive 1VIDD patients and healthy subjects (HS). Participants comprised 381VIDD patients and 42 age- and sex-matched HS were divided into groups based on their BDNF genotype. The effects of diagnosis and genotype, as well as the genotype-diagnosis interaction, in relation to brain morphology were evaluated using a voxel-by-voxel statistical analysis of high-resolution magnetic resonance imaging (MRI) findings. Among the Met-carriers, the volume of the left middle frontal gyms (composition of the prefrontal cortex [PFCI) was significantly smaller for MDD patients than for the HS, i.e., there was a significant genotype-diagnosis interaction effect on brain morphology noted in the left PFC. The BDNF polymorphism was associated with atrophy of the PFC in MDD patients, which suggests that the BDNF Va166Met polymorphism may play an important role in the pathogenesis of early stages of MDD. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
  • Shinji Matsunaga, Taro Kishi, Ichiro Yasue, Nakao Iwata
    The international journal of neuropsychopharmacology 19(2) 2015年7月28日  査読有り
    BACKGROUND: We performed a meta-analysis of cholinesterase inhibitors for patients with Lewy body disorders, such as Parkinson's disease, Parkinson's disease dementia, and dementia with Lewy bodies. METHODS: The meta-analysis included only randomized controlled trials of cholinesterase inhibitors for Lewy body disorders. RESULTS: Seventeen studies (n = 1798) were assessed. Cholinesterase inhibitors significantly improved cognitive function (standardized mean difference [SMD] = -0.53], behavioral disturbances (SMD = -0.28), activities of daily living (SMD = -0.28), and global function (SMD = -0.52) compared with control treatments. Changes in motor function were not significantly different from control treatments. Furthermore, the cholinesterase inhibitor group had a higher all-cause discontinuation (risk ratio [RR] = 1.48, number needed to harm [NNH] = 14), discontinuation due to adverse events (RR = 1.59, NNH = 20), at least one adverse event (RR = 1.13, NNH = 11), nausea (RR = 2.50, NNH = 13), and tremor (RR = 2.30, NNH = 20). CONCLUSIONS: Cholinesterase inhibitors appear beneficial for the treatment of Lewy body disorders without detrimental effects on motor function. However, a careful monitoring of treatment compliance and side effects is required.
  • Kazutaka Ohi, Ryota Hashimoto, Masashi Ikeda, Hidenaga Yamamori, Yuka Yasuda, Michiko Fujimoto, Satomi Umeda-Yano, Masaki Fukunaga, Haruo Fujino, Yoshiyuki Watanabe, Masao Iwase, Hiroaki Kazui, Nakao Iwata, Daniel R Weinberger, Masatoshi Takeda
    Schizophrenia bulletin 41(4) 909-18 2015年7月  査読有り
    Cognitive impairments are a core feature in patients with schizophrenia. These deficits could serve as effective tools for understanding the genetic architecture of schizophrenia. This study investigated whether genetic variants associated with cognitive impairments aggregate in functional gene networks related to the pathogenesis of schizophrenia. Here, genome-wide association studies (GWAS) of a range of cognitive phenotypes relevant to schizophrenia were performed in 411 healthy subjects. We attempted to replicate the GWAS data using 257 patients with schizophrenia and performed a meta-analysis of the GWAS findings and the replicated results. Because gene networks, rather than a single gene or genetic variant, may be strongly associated with the susceptibility to schizophrenia and cognitive impairments, gene-network analysis for genes in close proximity to the replicated variants was performed. We observed nominal associations between 3054 variants and cognitive phenotypes at a threshold of P < 1.0 × 10(-) (4). Of the 3054 variants, the associations of 191 variants were replicated in the replication samples (P < .05). However, no variants achieved genome-wide significance in a meta-analysis (P > 5.0 × 10(-) (8)). Additionally, 115 of 191 replicated single nucleotide polymorphisms (SNPs) have genes located within 10 kb of the SNPs (60.2%). These variants were moderately associated with cognitive phenotypes that ranged from P = 2.50 × 10(-) (5) to P = 9.40 × 10(-) (8). The genes located within 10 kb from the replicated SNPs were significantly grouped in terms of glutamate receptor activity (false discovery rate (FDR) q = 4.49 × 10(-) (17)) and the immune system related to major histocompatibility complex class I (FDR q = 8.76 × 10(-) (11)) networks. Our findings demonstrate that genetic variants related to cognitive trait impairment in schizophrenia are involved in the N-methyl-d-aspartate glutamate network.
  • Joey W Trampush, Todd Lencz, Emma Knowles, Gail Davies, Saurav Guha, Itsik Pe'er, David C Liewald, John M Starr, Srdjan Djurovic, Ingrid Melle, Kjetil Sundet, Andrea Christoforou, Ivar Reinvang, Semanti Mukherjee, Pamela DeRosse, Astri Lundervold, Vidar M Steen, Majnu John, Thomas Espeseth, Katri Räikkönen, Elisabeth Widen, Aarno Palotie, Johan G Eriksson, Ina Giegling, Bettina Konte, Masashi Ikeda, Panos Roussos, Stella Giakoumaki, Katherine E Burdick, Antony Payton, William Ollier, Mike Horan, Matthew Scult, Dwight Dickinson, Richard E Straub, Gary Donohoe, Derek Morris, Aiden Corvin, Michael Gill, Ahmad Hariri, Daniel R Weinberger, Neil Pendleton, Nakao Iwata, Ariel Darvasi, Panos Bitsios, Dan Rujescu, Jari Lahti, Stephanie Le Hellard, Matthew C Keller, Ole A Andreassen, Ian J Deary, David C Glahn, Anil K Malhotra
    American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 168B(5) 363-73 2015年7月  査読有り
    Cognitive deficits and reduced educational achievement are common in psychiatric illness; understanding the genetic basis of cognitive and educational deficits may be informative about the etiology of psychiatric disorders. A recent, large genome-wide association study (GWAS) reported a genome-wide significant locus for years of education, which subsequently demonstrated association to general cognitive ability ("g") in overlapping cohorts. The current study was designed to test whether GWAS hits for educational attainment are involved in general cognitive ability in an independent, large-scale collection of cohorts. Using cohorts in the Cognitive Genomics Consortium (COGENT; up to 20,495 healthy individuals), we examined the relationship between g and variants associated with educational attainment. We next conducted meta-analyses with 24,189 individuals with neurocognitive data from the educational attainment studies, and then with 53,188 largely independent individuals from a recent GWAS of cognition. A SNP (rs1906252) located at chromosome 6q16.1, previously associated with years of schooling, was significantly associated with g (P = 1.47 × 10(-4) ) in COGENT. The first joint analysis of 43,381 non-overlapping individuals for this a priori-designated locus was strongly significant (P = 4.94 × 10(-7) ), and the second joint analysis of 68,159 non-overlapping individuals was even more robust (P = 1.65 × 10(-9) ). These results provide independent replication, in a large-scale dataset, of a genetic locus associated with cognitive function and education. As sample sizes grow, cognitive GWAS will identify increasing numbers of associated loci, as has been accomplished in other polygenic quantitative traits, which may be relevant to psychiatric illness.
  • Taro Kishi, Shinji Matsunaga, Kazuto Oya, Toshikazu Ikuta, Nakao Iwata
    The international journal of neuropsychopharmacology 18(12) 2015年6月19日  査読有り
    BACKGROUND: There has not been conclusive evidence for prevention of brain atrophy by anti-dementia drugs in mild cognitive impairment and Alzheimer's Disease. METHODS: Relevant studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations up to 16 May, 2015. Only double-blind, randomized, placebo-controlled clinical trials of anti-dementia drugs in patients with mild cognitive impairment or Alzheimer's Disease were included. Primary outcomes were annualized percent change of total brain volume (%TBV/y), annualized percent change of hippocampal volume (%HV/y), and annualized percent change of ventricular volume (%VV/y) measured by magnetic resonance imaging. Standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated for relevant outcomes. RESULTS: Seven randomized, placebo-controlled clinical trials (n=1708) were found to meet the inclusion criteria, including 4 mild cognitive impairment studies (n=1327) and 3 Alzheimer's Disease studies (n=381) [3 donepezil studies (2 mild cognitive impairment studies and 1 Alzheimer's Disease study), 1 galantaime study for mild cognitive impairment, 2 mementine studies for Alzheimer's Disease, and 1 rivastigmine study for mild cognitive impairment]. Pooled anti-dementia drugs showed superior protective outcomes compared with placebo regarding %TBV/y (SMD=-0.21, 95%CI=-0.37 to -0.04, P=.01, N=4, n=624) and %VV/y (SMD=-0.79, 95%CI=-1.40 to -0.19, P=.01, N=3, n=851). However, %HV/y failed to show difference between both groups. Among anti-dementia drugs, donepezil showed significantly greater protective effects than placebo regarding %TBV/y (SMD=-0.43, 95%CI=-0.74 to -0.12, P=.007, N=1, n=164) and %VV/y (SMD=-0.51, 95%CI=-0.73 to -0.29, P<.00001, N=2, n=338). Rivastigmine was also superior to placebo regarding %VV/y (SMD=-1.33, 95%CI=-1.52 to -1.14, P<.00001). CONCLUSIONS: The results favored the hypothesis that anti-dementia drugs may prevent brain atrophy in patients with mild cognitive impairment and Alzheimer's Disease.
  • Masakazu Hatano, Masashi Ikeda, Kenji Kondo, Takeo Saito, Ayu Shimasaki, Kosei Esaki, Wakako Umene-Nakano, Reiji Yoshimura, Jun Nakamura, Norio Ozaki, Nakao Iwata
    Journal of human genetics 60(6) 343-4 2015年6月  査読有り
  • Hiroki Kimura, Daisuke Tsuboi, Chenyao Wang, Itaru Kushima, Takayoshi Koide, Masashi Ikeda, Yoshimi Iwayama, Tomoko Toyota, Noriko Yamamoto, Shohko Kunimoto, Yukako Nakamura, Akira Yoshimi, Masahiro Banno, Jingrui Xing, Yuto Takasaki, Mami Yoshida, Branko Aleksic, Yota Uno, Takashi Okada, Tetsuya Iidaka, Toshiya Inada, Michio Suzuki, Hiroshi Ujike, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Nakao Iwata, Kozo Kaibuchi, Norio Ozaki
    Schizophrenia bulletin 41(3) 744-53 2015年5月  査読有り
    BACKGROUND: Nuclear distribution E homolog 1 (NDE1), located within chromosome 16p13.11, plays an essential role in microtubule organization, mitosis, and neuronal migration and has been suggested by several studies of rare copy number variants to be a promising schizophrenia (SCZ) candidate gene. Recently, increasing attention has been paid to rare single-nucleotide variants (SNVs) discovered by deep sequencing of candidate genes, because such SNVs may have large effect sizes and their functional analysis may clarify etiopathology. METHODS AND RESULTS: We conducted mutation screening of NDE1 coding exons using 433 SCZ and 145 pervasive developmental disorders samples in order to identify rare single nucleotide variants with a minor allele frequency ≤5%. We then performed genetic association analysis using a large number of unrelated individuals (3554 SCZ, 1041 bipolar disorder [BD], and 4746 controls). Among the discovered novel rare variants, we detected significant associations between SCZ and S214F (P = .039), and between BD and R234C (P = .032). Furthermore, functional assays showed that S214F affected axonal outgrowth and the interaction between NDE1 and YWHAE (14-3-3 epsilon; a neurodevelopmental regulator). CONCLUSIONS: This study strengthens the evidence for association between rare variants within NDE1 and SCZ, and may shed light into the molecular mechanisms underlying this severe psychiatric disorder.
  • Taro Kishi, Yuki Matsuda, Tomohiko Mukai, Shinji Matsunaga, Ichiro Yasue, Kiyoshi Fujita, Tomo Okochi, Shigeki Hirano, Yusuke Kajio, Toshihiko Funahashi, Kaku Akamatsu, Kei Ino, Momoko Okuda, Hideaki Tabuse, Nakao Iwata
    Comprehensive psychiatry 59 91-7 2015年5月  査読有り
    We conducted a cross-sectional survey to assess the prevalence of physical pain in Japanese major depressive disorder (MDD) and schizophrenia (SZ) patients as well as in healthy controls (HCs). We also examined the association between their psychopathology and characteristics of pain according to a face-to-face survey by an experienced psychiatrist and psychologist. We analyzed 233 HCs, 94 MDD patients, and 75 SZ patients using the McGill Pain Questionnaire (MPQ) and SF-8 (all participants), the Hamilton Depression Rating Scale 21 items (MDD patients), and the Positive and Negative Symptom Scale (SZ patients). Although MDD patients experienced more pain than HCs, there was no difference in the prevalence of pain between SZ patients and HCs. Moreover, HCs with pain did not have higher SF-8 total scores than those without pain, whereas both MDD and SZ patients with pain had higher SF-8 total scores than those without pain. The severity of psychopathology in MDD and SZ patients was also positively associated with both the prevalence of pain and MPQ scores. MPQ scores were also associated with positive symptoms in SZ patients. Considering these results, physicians need to query MDD patients about physical pain during examination if they are to ensure a favorable and quick response to treatment. The severity of positive symptoms (i.e., clinical status) in SZ patients might also be associated with pain sensitivity, and warrants further investigation.
  • Shinji Matsunaga, Taro Kishi, Nakao Iwata
    The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry 23(4) 373-383 2015年4月  査読有り
    OBJECTIVE: To clarify whether memantine is more efficacious in several outcomes and safer than placebo in patients with Lewy body disorders, we performed a meta-analysis of memantine in patients with Lewy body disorders. METHODS: The meta-analysis included randomized controlled trials of memantine for Lewy body disorders in all patients with Lewy body disorders. Motor function, activities of daily living, Neuropsychiatric Inventory, Mini-Mental State Exam, discontinuation rate, and individual side effects were evaluated. RESULTS: No significant effects of memantine on motor function scores, Mini-Mental State Exam scores, Neuropsychiatric Inventory scores, and activity of daily living scores were found. However, memantine was superior to placebo in Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change scores (standardized mean difference: -0.26; 95% confidence interval: -0.51 to -0.02; z = 2.08; p = 0.04; two studies; N = 258). Dropout due to all causes, inefficacy, or adverse events were similar in both groups. Moreover, no significant differences in serious adverse events, somnolence/tiredness, stroke, dizziness/vertigo, and confusion were found between the groups. CONCLUSION: Our results suggest that memantine did not have a benefit for the treatment of Lewy body disorders in cognition and motor function. However, memantine may be superior to placebo for the overall impression of the disorders. Further, memantine is well tolerated.
  • Taro Kishi, Nakao Iwata
    European archives of psychiatry and clinical neuroscience 265(3) 259-68 2015年4月  査読有り
    We performed an updated meta-analysis of randomized double-blind placebo-controlled trials (RCTs) on the effects of varenicline adjuvant therapy for smoking cessation in people with schizophrenia, on the basis of a previous meta-analysis (Tsoi in Cochrane Database Syst Rev 2:CD007253, 2013). We searched PubMed, the Cochrane Library databases, and PsycINFO up to August 1, 2014. RCTs comparing varenicline adjuvant therapy with placebo in schizophrenia were included. The risk ratio (RR), number needed to harm (NNH), and standardized mean differences with its 95% confidence interval (CI) were used. Seven studies (total n = 439), including 6 with only schizophrenia (total n = 352), 1 with both schizophrenia (n = 77) and bipolar disorder (n = 10), were included. Varenicline was not superior to placebo in smoking cessation (RR = 0.79, 95% CI 0.58-1.08, p = 0.14, 5 RCTs, n = 322). Varenicline failed to show its superiority to placebo for overall, positive, negative, and depressive symptoms. Moreover, there was no significant difference in the discontinuation rate due to all causes, clinical deterioration, or side effects between varenicline and placebo. Although varenicline caused less abnormal dreams/nightmares than placebo (RR = 0.47, 95% CI 0.22-0.99, p = 0.05, NNH = not significant, 4 RCTs, n = 288), it caused more nausea (RR = 1.79, 95% CI 1.20-2.67, p = 0.004, NNH = 6, p = 0.004, 6 RCTs, n = 417). We detected no significant difference in suicidal ideation and depression between varenicline and placebo. Our results suggest that although varenicline adjuvant therapy is well tolerated, varenicline is not superior to placebo for smoking cessation in people with schizophrenia. Because of the limited sample sizes of the available studies, future studies will require larger samples to ensure that these findings are generalizable.
  • Brendan Bulik-Sullivan, Schizophrenia Working Group of the Psychiatric Genomics Consortium, Po-Ru Loh, Hilary K. Finucane, Stephan Ripke, Jian Yang, Nick Patterson, Mark J. Daly, Alkes L. Price, Benjamin M. Neale, Aiden Corvin, James T.R. Walters, Kai-How Farh, Peter A. Holmans, Phil Lee, David A. Collier, Hailiang Huang, Tune H. Pers, Ingrid Agartz, Esben Agerbo, Margot Albus, Madeline Alexander, Farooq Amin, Silviu A. Bacanu, Martin Begemann, Richard A. Belliveau, Judit Bene, Sarah E. Bergen, Elizabeth Bevilacqua, Tim B. Bigdeli, Donald W. Black, Richard Bruggeman, Nancy G. Buccola, Randy L. Buckner, William Byerley, Wiepke Cahn, Guiqing Cai, Murray J. Cairns, Dominique Campion, Rita M. Cantor, Vaughan J. Carr, Noa Carrera, Stanley V. Catts, Kimberly D. Chambert, Raymond C.K. Chan, Ronald Y.L. Chen, Eric Y.H. Chen, Wei Cheng, Eric F.C. Cheung, Siow Ann Chong, C. Robert Cloninger, David Cohen, Nadine Cohen, Paul Cormican, Nick Craddock, Benedicto Crespo-Facorro, James J. Crowley, David Curtis, Michael Davidson, Kenneth L. Davis, Franziska Degenhardt, Jurgen Del Favero, Lynn E. DeLisi, Ditte Demontis, Dimitris Dikeos, Timothy Dinan, Srdjan Djurovic, Gary Donohoe, Elodie Drapeau, Jubao Duan, Frank Dudbridge, Naser Durmishi, Peter Eichhammer, Johan Eriksson, Valentina Escott-Price, Laurent Essioux, Ayman H. Fanous, Martilias S. Farrell, Josef Frank, Lude Franke, Robert Freedman, Nelson B. Freimer, Marion Friedl, Joseph I. Friedman, Menachem Fromer, Giulio Genovese, Lyudmila Georgieva, Elliot S. Gershon, Ina Giegling, Paola Giusti-Rodríguez, Stephanie Godard, Jacqueline I. Goldstein, Vera Golimbet, Srihari Gopal, Jacob Gratten, Lieuwe De Haan, Christian Hammer, Marian L. Hamshere, Mark Hansen, Thomas Hansen, Vahram Haroutunian, Annette M. Hartmann, Frans A. Henskens, Stefan Herms, Joel N. Hirschhorn, Per Hoffmann, Andrea Hofman, Mads V. Hollegaard, David M. Hougaard, Masashi Ikeda, Inge Joa, Antonio Juliá, René S. Kahn, Luba Kalaydjieva, Sena Karachanak-Yankova, Juha Karjalainen, David Kavanagh, Matthew C. Keller, Brian J. Kelly, James L. Kennedy, Andrey Khrunin, Yunjung Kim, Janis Klovins, James A. Knowles, Bettina Konte, Vaidutis Kucinskas, Zita Ausrele Kucinskiene, Hana Kuzelova-Ptackova, Anna K. Kähler, Claudine Laurent, Jimmy Lee Chee Keong, S. Hong Lee, Sophie E. Legge, Bernard Lerer, Miaoxin Li, Tao Li, Kung-Yee Liang, Jeffrey Lieberman, Svetlana Limborska, Carmel M. Loughland, Jan Lubinski, Jouko Lönnqvist, Milan Macek, Patrik K.E. Magnusson, Brion S. Maher, Wolfgang Maier, Jacques Mallet, Sara Marsal, Manuel Mattheisen, Morten Mattingsdal, Robert W. McCarley, Colm McDonald, Andrew M. McIntosh, Sandra Meier, Carin J. Meijer, Bela Melegh, Ingrid Melle, Raquelle I. Mesholam-Gately, Andres Metspalu, Patricia T. Michie, Lili Milani, Vihra Milanova, Younes Mokrab, Derek W. Morris, Ole Mors, Kieran C. Murphy, Robin M. Murray, Inez Myin-Germeys, Bertram Müller-Myhsok, Mari Nelis, Igor Nenadic, Deborah A. Nertney, Gerald Nestadt, Kristin K. Nicodemus, Liene Nikitina-Zake, Laura Nisenbaum, Annelie Nordin, Eadbhard O'Callaghan, Colm O'Dushlaine, F. Anthony O'Neill, Sang-Yun Oh, Ann Olincy, Line Olsen, Jim Van Os, Christos Pantelis, George N. Papadimitriou, Sergi Papiol, Elena Parkhomenko, Michele T. Pato, Tiina Paunio, Milica Pejovic-Milovancevic, Diana O. Perkins, Olli Pietiläinen, Jonathan Pimm, Andrew J. Pocklington, John Powell, Ann E. Pulver, Shaun M. Purcell, Digby Quested, Henrik B. Rasmussen, Abraham Reichenberg, Mark A. Reimers, Alexander L. Richards, Joshua L. Roffman, Panos Roussos, Douglas M. Ruderfer, Veikko Salomaa, Alan R. Sanders, Ulrich Schall, Christian R. Schubert, Thomas G. Schulze, Sibylle G. Schwab, Edward M. Scolnick, Rodney J. Scott, Larry J. Seidman, Jianxin Shi, Engilbert Sigurdsson, Teimuraz Silagadze, Jeremy M. Silverman, Kang Sim, Petr Slominsky, Jordan W. Smoller, Hon-Cheong So, Chris C.A. Spencer, Eli A. Stahl, Hreinn Stefansson, Stacy Steinberg, Elisabeth Stogmann, Richard E. Straub, Eric Strengman, Jana Strohmaier, T. Scott Stroup, Mythily Subramaniam, Jaana Suvisaari, Dragan M. Svrakic, Jin P. Szatkiewicz, Erik Söderman, Srinivas Thirumalai, Draga Toncheva, Paul A. Tooney, Sarah Tosato, Juha Veijola, John Waddington, Dermot Walsh, Dai Wang, Qiang Wang, Bradley T. Webb, Mark Weiser, Dieter B. Wildenauer, Nigel M. Williams, Stephanie Williams, Stephanie H. Witt, Aaron R. Wolen, Emily H.M. Wong, Brandon K. Wormley, Jing Qin Wu, Hualin Simon Xi, Clement C. Zai, Xuebin Zheng, Fritz Zimprich, Naomi R. Wray, Kari Stefansson, Peter M. Visscher, Rolf Adolfsson, Ole A. Andreassen, Douglas H.R. Blackwood, Elvira Bramon, Joseph D. Buxbaum, Anders D. Børglum, Sven Cichon, Ariel Darvasi, Enrico Domenici, Hannelore Ehrenreich, Tõnu Esko, Pablo V. Gejman, Michael Gill, Hugh Gurling, Christina M. Hultman, Nakao Iwata, Assen V. Jablensky, Erik G. Jönsson, Kenneth S. Kendler, George Kirov, Jo Knight, Todd Lencz, Douglas F. Levinson, Qingqin S. Li, Jianjun Liu, Anil K. Malhotra, Steven A. McCarroll, Andrew McQuillin, Jennifer L. Moran, Preben B. Mortensen, Bryan J. Mowry, Markus M. Nöthen, Roel A. Ophoff, Michael J. Owen, Aarno Palotie, Carlos N. Pato, Tracey L. Petryshen, Danielle Posthuma, Marcella Rietschel, Brien P. Riley, Dan Rujescu, Pak C. Sham, Pamela Sklar, David St Clair, Daniel R. Weinberger, Jens R. Wendland, Thomas Werge, Patrick F. Sullivan, Michael C. O'Donovan
    Nature Genetics 47(3) 291-295 2015年2月25日  査読有り
    Both polygenicity (many small genetic effects) and confounding biases, such as cryptic relatedness and population stratification, can yield an inflated distribution of test statistics in genome-wide association studies (GWAS). However, current methods cannot distinguish between inflation from a true polygenic signal and bias. We have developed an approach, LD Score regression, that quantifies the contribution of each by examining the relationship between test statistics and linkage disequilibrium (LD). The LD Score regression intercept can be used to estimate a more powerful and accurate correction factor than genomic control. We find strong evidence that polygenicity accounts for the majority of the inflation in test statistics in many GWAS of large sample size.
  • Masashi Ikeda, Reiji Yoshimura, Ryota Hashimoto, Kenji Kondo, Takeo Saito, Ayu Shimasaki, Kazutaka Ohi, Mamoru Tochigi, Yoshiya Kawamura, Nao Nishida, Taku Miyagawa, Tsukasa Sasaki, Katsushi Tokunaga, Kiyoto Kasai, Masatoshi Takeda, Jun Nakamura, Norio Ozaki, Nakao Iwata
    Journal of clinical psychopharmacology 35(1) 85-8 2015年2月  査読有り
  • Jun Ishigooka, Jun Nakamura, Yasuo Fujii, Nakao Iwata, Toshifumi Kishimoto, Masaomi Iyo, Naohisa Uchimura, Ryoji Nishimura, Naoaki Shimizu
    Schizophrenia research 161(2-3) 421-8 2015年2月  査読有り
    OBJECTIVE: This study was designed to evaluate efficacy and safety of aripiprazole once-monthly (AOM) by verifying non-inferiority of AOM to oral aripiprazole in Asian patients with schizophrenia. METHOD: The study consisted of a screening phase and three phases: an oral conversion phase (≤12weeks), an oral stabilization phase (≤12weeks) and a 52-week double-blind phase. Patients meeting stabilization criteria for 4weeks during the oral stabilization phase were randomly assigned (1:1) to AOM (400mg) or oral aripiprazole (6-24mg/day). The primary endpoint was Kaplan-Meier estimated rate of non-exacerbation of psychotic symptoms/non-relapse at Week 26. RESULTS: A total of 724 patients were screened, and 502 patients entered the oral stabilization phase. Of 455 patients randomized in the double-blind phase, 228 received AOM and 227 received oral aripiprazole. The non-exacerbation of psychotic symptoms/non-relapse rates at Week 26 were 95.0% (AOM) and 94.7% (oral aripiprazole) and the difference was 0.3% (95% CI: -3.9,4.5), thus non-inferiority of AOM compared to oral aripiprazole with respect to non-exacerbation of psychotic symptoms/non-relapse rate was shown with a margin of -3.9% which is well above the pre-defined non-inferiority limit (-15%). The proportions of patients meeting exacerbation of psychotic symptoms/relapse criteria and stabilization of psychotic symptoms/maintenance criteria were 6.6% and 92.5% in both groups. Discontinuation rates due to all reasons were 25.9% (AOM) and 33.5% (oral aripiprazole). AOM was well tolerated as well as oral aripiprazole. CONCLUSIONS: Non-inferiority of AOM to oral aripiprazole was established. AOM is efficacious in maintenance treatment of stabilized schizophrenia, with comparable efficacy and tolerability to oral aripiprazole. CLINICAL TRIALS REGISTRATION: JapicCTI-101175.
  • Momoko Kubo, Taro Kishi, Shinji Matsunaga, Nakao Iwata
    Journal of Alzheimer's disease : JAD 48(3) 667-71 2015年  査読有り
    BACKGROUND: No comprehensive meta-analysis has been performed concerning the efficacy and tolerability of histamine H3 receptor antagonists (H3R-ANTs) in Alzheimer's disease patients. OBJECTIVE: We performed a systematic review and meta-analysis of double-blind randomized placebo-controlled trials (RCTs) of H3R-ANTs for Alzheimer's disease. METHODS: Relevant studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations up to June 19, 2015. The primary outcome was a change in the Mini-Mental State Examination (MMSE) scores. Secondary outcomes were Neuropsychiatric Inventory (NPI) scores, discontinuation rate, and individual adverse events/side effects. Risk ratios, numbers-needed-to-treat/harm, and standardized mean differences were calculated based on a random effects model. RESULTS: The computerized search initially yielded 33 studies after excluding duplicates. We excluded 29 of these articles following a review of titles and abstracts and one RCT including healthy subjects after full-text review. We identified three RCTs (two on GSK239512 and one on ABT-288) including 402 patients. Pooled H3R-ANTs were not superior to placebo for improvement in MMSE and NPI scores. Discontinuation rate and individual adverse events/side effects did not differ among the pooled groups. CONCLUSIONS: Our results suggest that H3R-ANTs are not effective in treating cognitive dysfunction in Alzheimer's disease. However, further studies with larger samples are required for definitive conclusions regarding responsive subpopulations.
  • Yoshio Yamanouchi, Tsuruhei Sukegawa, Ataru Inagaki, Toshiya Inada, Takashi Yoshio, Reiji Yoshimura, Nakao Iwata
    Seishin shinkeigaku zasshi = Psychiatria et neurologia Japonica 117(4) 305-11 2015年  査読有り
    Compared with other countries, Japan exhibits prominent levels of antipsychotic polypharmacy and high-dose regimens. In view of these circumstances, the Safe Correction of Antipsychotic Polypharmacy and high-dose regimens (SCAP) method was developed based on previous findings as a realistic way to reduce medication consumption in patients already experiencing polypharmacy and high-dose regimens. In the SCAP method, "clinicians can reduce medications one by one, gradually, with occasional breaks permitted." A clinical study conducted to evaluate this method found no change in clinical symptoms, side effects, or quality of life (QOL), and the number of withdrawals due to aggravation was also small. A leaflet describing these results, and which is designed to support efforts to reduce medications, has been released. Future research will involve the examination and analysis of data from this study, taking into account its limitations, with a view toward developing guidelines applicable to clinical settings. The pragmatic, gradual correction of polypharmacy and high-dose regimens that goes beyond the "multiple drugs or single agent" dichotomy can decrease the burden experienced by patients. This is a practical approach that can be applied when developing comprehensive plans for the future psychiatric care of aging patient populations.
  • Taro Kishi, Yuki Matsuda, Shinji Matsunaga, Nakao Iwata
    Neuropsychiatric disease and treatment 11 419-34 2015年  査読有り
    BACKGROUND: We conducted a systematic review and meta-analysis of randomized controlled trials comparing aripiprazole with pooled antipsychotics in Japanese patients with schizophrenia. METHODS: We performed a literature search of data published in PubMed(®), the Cochrane Library database, the Japan Medical Abstracts Society, and PsycINFO(®) up to January 5, 2014. The odds ratio (OR), number-needed-to-harm (NNH), and standardized mean difference (SMD) based on a random effects model were calculated. RESULTS: We identified five relevant studies (seven comparisons, n=684; one comparison each for haloperidol [n=243], mosapramine [n=238], olanzapine [n=39], quetiapine [n=42], perospirone [n=100], and two comparisons for risperidone [n=66]). There were no significant differences in the Positive and Negative Syndrome Scale (PANSS) total, negative, and general scores (SMD=0.10, SMD=-0.09, SMD=0.10, respectively); discontinuation rate associated with all causes (OR=1.35); or side effects (OR=1.03) between aripiprazole and the pooled antipsychotics. Aripiprazole was inferior to the pooled antipsychotics in PANSS positive subscale scores (SMD=0.17) and discontinuation because of inefficacy (OR=2.21, NNH=11). However, aripiprazole had fewer side effects compared with the pooled antipsychotics (OR=0.21, NNH=20 for one or more side effects), including fatigue (OR=0.22, NNH=8), hyperprolactinemia (OR=0.00, NNH=1), extrapyramidal symptoms (OR=0.46, NNH=6), and weight gain (OR=0.36, NNH=7). Moreover, aripiprazole was associated with lower total cholesterol (SMD=-0.20) and triglyceride (SMD=-0.17) levels and body weight (SMD=-0.20) compared with the pooled antipsychotics. CONCLUSION: Although the discontinuation rate associated with inefficacy was higher with aripiprazole than with the pooled antipsychotics, aripiprazole was associated with a lower risk of hyperprolactinemia and metabolic and extrapyramidal symptoms compared with the pooled antipsychotics.
  • Shinji Matsunaga, Taro Kishi, Nakao Iwata
    PloS one 10(4) e0123289 2015年  査読有り
    BACKGROUND: We performed an updated meta-analysis of randomized placebo-controlled trials testing memantine monotherapy for patients with Alzheimer's disease (AD). METHODS: The meta-analysis included randomized controlled trials of memantine monotherapy for AD, omitting those in which patients were also administered a cholinesterase inhibitor. Cognitive function, activities of daily living, behavioral disturbances, global function, stage of dementia, drug discontinuation rate, and individual side effects were compared between memantine monotherapy and placebo groups. The primary outcomes were cognitive function and behavioral disturbances; the others were secondary outcomes. RESULTS: Nine studies including 2433 patients that met the study's inclusion criteria were identified. Memantine monotherapy significantly improved cognitive function [standardized mean difference (SMD)=-0.27, 95% confidence interval (CI)=-0.39 to -0.14, p=0.0001], behavioral disturbances (SMD=-0.12, 95% CI=-0.22 to -0.01, p=0.03), activities of daily living (SMD=-0.09, 95% CI=-0.19 to -0.00, p=0.05), global function assessment (SMD=-0.18, 95% CI=-0.27 to -0.09, p=0.0001), and stage of dementia (SMD=-0.23, 95% CI=-0.33 to -0.12, p=0.0001) scores. Memantine was superior to placebo in terms of discontinuation because of inefficacy [risk ratio (RR)=0.36, 95% CI=0.17¬ to 0.74, p=0.006, number needed to harm (NNH)=non significant]. Moreover, memantine was associated with less agitation compared with placebo (RR=0.68, 95% CI=0.49 to 0.94, p=0.02, NNH=non significant). There were no significant differences in the rate of discontinuation because of all causes, all adverse events, and individual side effects other than agitation between the memantine monotherapy and placebo groups. CONCLUSIONS: Memantine monotherapy improved cognition, behavior, activities of daily living, global function, and stage of dementia and was well-tolerated by AD patients. However, the effect size in terms of efficacy outcomes was small and thus there is limited evidence of clinical benefit.
  • Taro Kishi, Shinji Matsunaga, Nakao Iwata
    PloS one 10(8) e0136910 2015年  査読有り
    OBJECTIVE: We performed a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials evaluating suvorexant for primary insomnia. METHODS: Relevant studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations through June 27, 2015. We performed a systematic review and meta-analysis of suvorexant trial efficacy and safety outcomes. The primary efficacy outcomes were either subjective total sleep time (sTST) or subjective time-to-sleep onset (sTSO) at 1 month. The secondary outcomes were other efficacy outcomes, discontinuation rate, and individual adverse events. The risk ratio, number-needed-to-treat/harm, and weighted mean difference (WMD) and 95% confidence intervals (CI) based on a random effects model were calculated. RESULTS: The computerized literature database search initially yielded 48 results, from which 37 articles were excluded following a review of titles and abstracts and another eight review articles after full-text review. Thus, we identified 4 trials that included a total of 3,076 patients. Suvorexant was superior to placebo with regard to the two primary efficacy outcomes (sTST: WMD = -20.16, 95% CI = -25.01 to -15.30, 1889 patients, 3 trials, sTSO: WMD = -7.62, 95% CI = -11.03 to -4.21, 1889 patients, 3 trials) and was not different from placebo in trial discontinuations. Suvorexant caused a higher incidence than placebo of at least one side effects, abnormal dreams, somnolence, excessive daytime sleepiness/sedation, fatigue, dry mouth, and rebound insomnia. CONCLUSIONS: Our analysis of published trial results suggests that suvorexant is effective in treating primary insomnia and is well-tolerated.
  • Kazuto Oya, Taro Kishi, Nakao Iwata
    Neuropsychiatric disease and treatment 11 2299-307 2015年  査読有り
    OBJECTIVE: We conducted a systematic review and meta-analysis of the efficacy of aripiprazole once monthly (AOM) for schizophrenia. METHODS: Randomized controlled trials (RCTs) on AOM, published until June 25, 2015, were retrieved from PubMed, Cochrane, and PsycINFO databases. Relative risk (RR), standardized mean difference (SMD), 95% confidence intervals (95% CIs), and numbers needed to treat/harm (NNT/NNH) were calculated. RESULTS: We identified four relevant RCTs (total n=1,860), two placebo-controlled trials, one noninferiority trial comparing AOM to oral aripiprazole (OA), and one including therapeutic doses of AOM and OA, as well as an AOM dose below therapeutic threshold (control arm). AOM was superior to placebo for decreasing Positive and Negative Syndrome Scale (PANSS) total scores (SMD =-0.65, 95% CI =-0.90 to -0.41, n=1,126). However, PANSS total scores did not differ significantly between pooled AOM and OA groups. The pooled AOM group showed significantly lower incidence of all-cause discontinuation (RR =0.54, 95% CI =0.41-0.71, n=1,139, NNH =4) and inefficacy (RR =0.28, 95% CI =0.21-0.38, n=1,139, NNH =5) than placebo, but was not superior to placebo regarding discontinuation due to adverse events (AEs) or death. The AOM group exhibited a lower incidence of all-cause discontinuation than OA (RR =0.78, 95% CI =0.64-0.95, n=986, NNH =14), but there were no intergroup differences in discontinuation due to inefficacy, AEs, or death. There were no significant differences in extrapyramidal symptoms scale scores between AOM and placebo or between AOM and OA. AOM resulted in higher weight gain than placebo (SMD =0.41, 95% CI =0.18-0.64, n=734) but lower than OA (SMD =-0.16, 95% CI =-0.29 to -0.02, n=847). CONCLUSION: AOM has antipsychotic efficacy and low risk of discontinuation due to AEs.
  • Shinji Matsunaga, Taro Kishi, Peter Annas, Hans Basun, Harald Hampel, Nakao Iwata
    Journal of Alzheimer's disease : JAD 48(2) 403-10 2015年  査読有り
    BACKGROUND: This is the first meta-analysis of randomized placebo-controlled trials testing lithium as a treatment for patients with Alzheimer's disease (AD) and individuals with mild cognitive impairment (MCI). METHODS: The primary outcome measure was efficacy on cognitive performance as measured through the Alzheimer's Disease Assessment Scale cognitive subscale or the Mini-Mental State Examination. Other outcome measures were drug discontinuation rate, individual side effects, and biological markers (phosphorylated tau 181, total tau, and amyloid-β42) in cerebrospinal fluid (CSF). RESULTS: Three clinical trials including 232 participants that met the study's inclusion criteria were identified. Lithium significantly decreased cognitive decline as compared to placebo (standardized mean difference = -0.41, 95% confidence interval = -0.81 to -0.02, p = 0.04, I2 = 47% , 3 studies, n = 199). There were no significant differences in the rate of attrition, discontinuation due to all causes or adverse events, or CSF biomarkers between treatment groups. CONCLUSIONS: The results indicate that lithium treatment may have beneficial effects on cognitive performance in subjects with MCI and AD dementia.
  • Taro Kishi, Shinji Matsunaga, Nakao Iwata
    Neuropsychiatric disease and treatment 11 2883-5 2015年  査読有り
    BACKGROUND: There is no conclusive evidence supporting the efficacy of memantine in frontotemporal dementia (FTD). We conducted a comprehensive meta-analysis of memantine concerning the efficacy and tolerability of memantine in FTD. METHODS: Studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations up to April 10, 2015. Outcomes were Clinical Global Impression (primary), Mini-Mental State Examination, Neuropsychiatric Inventory, and Zarit Burden Interview scores as well as all-cause discontinuation. Standardized mean difference and risk ratio with 95% confidence interval were calculated. RESULTS: Two randomized controlled trials (RCTs) (total n=130) met the inclusion criteria. Memantine was marginally superior to placebo as assessed by the Clinical Global Impression scores (standardized mean difference =-0.34, 95% confidence interval =-0.68-0.01, P=0.06). However, there were no significant differences in Mini-Mental State Examination, Neuropsychiatric Inventory, and Zarit Burden Interview scores as well as all-cause discontinuation between memantine and placebo. CONCLUSION: Our results suggest that memantine may benefit FTD patients. However, because only two randomized controlled trials have addressed this issue, further studies using larger samples are needed.
  • T. Kishi, N. Iwata
    PHARMACOPSYCHIATRY 48(1) 30-36 2015年1月  査読有り
    Introduction: No comprehensive meta-analysis has been performed concerning the efficacy and tolerability of adjunctive therapy with histamine-2 receptor antagonists (H2R-ANTs) in schizophrenia patients who were treated with antipsychotics. Methods: Risk ratios, standardized mean differences (SMD), and 95% confidence intervals were calculated. Results: We included 8 double-blinded, randomized placebo-controlled trials (RCTs) (n=418) that met the inclusion criteria (famotidine: N=3, n=74; nizatidine: N=4, n=292; ranitidine: N=1, n=52). Pooled H2R-ANTs were not different from placebo with regard to reduction in overall symptoms and body weight. However, pooled H2R-ANTs resulted in lower body mass index (BMI) than placebo (SMD=-0.68). Moreover, nizatidine was associated with an increase in plasma leptin levels (SMD=-1.14). There were no significant differences in the discontinuation rates due to all-cause, side effects, and inefficacy between pooled H2R-ANTs and placebo. However, nizatidine produced more depression and dry mouth than placebo. Discussion: H2R-ANT adjunctive therapy did not improve overall symptoms. To clarify the opposite results between body weight and BMI, future research should investigate long-term efficacy and generate more safety data by using larger samples.
  • Taro Kishi, Shinji Matsunaga, Nakao Iwata
    NEUROPSYCHIATRIC DISEASE AND TREATMENT 11 2883-2885 2015年  査読有り
    Background: There is no conclusive evidence supporting the efficacy of memantine in frontotemporal dementia (FTD). We conducted a comprehensive meta-analysis of memantine concerning the efficacy and tolerability of memantine in FTD. Methods: Studies were identified through searches of PubMed, databases of the Cochrane Library, and PsycINFO citations up to April 10, 2015. Outcomes were Clinical Global Impression (primary), Mini-Mental State Examination, Neuropsychiatric Inventory, and Zarit Burden Interview scores as well as all-cause discontinuation. Standardized mean difference and risk ratio with 95% confidence interval were calculated. Results: Two randomized controlled trials (RCTs) (total n=130) met the inclusion criteria. Memantine was marginally superior to placebo as assessed by the Clinical Global Impression scores (standardized mean difference =-0.34, 95% confidence interval =-0.68-0.01, P=0.06). However, there were no significant differences in Mini-Mental State Examination, Neuropsychiatric Inventory, and Zarit Burden Interview scores as well as all-cause discontinuation between memantine and placebo. Conclusion: Our results suggest that memantine may benefit FTD patients. However, because only two randomized controlled trials have addressed this issue, further studies using larger samples are needed.
  • Taro Kishi, Yuki Matsuda, Shinji Matsunaga, Nakao Iwata
    NEUROPSYCHIATRIC DISEASE AND TREATMENT 11 419-434 2015年  査読有り
    Background: We conducted a systematic review and meta-analysis of randomized controlled trials comparing aripiprazole with pooled antipsychotics in Japanese patients with schizophrenia. Methods: We performed a literature search of data published in PubMed (R), the Cochrane Library database, the Japan Medical Abstracts Society, and PsycINFO (R) up to January 5, 2014. The odds ratio (OR), number-needed-to-harm (NNH), and standardized mean difference (SMD) based on a random effects model were calculated. Results: We identified five relevant studies (seven comparisons, n=684; one comparison each for haloperidol [n=243], mosapramine [n=238], olanzapine [n=39], quetiapine [n=42], perospirone [n=100], and two comparisons for risperidone [n=66]). There were no significant differences in the Positive and Negative Syndrome Scale (PANSS) total, negative, and general scores (SMD=0.10, SMD=-0.09, SMD=0.10, respectively); discontinuation rate associated with all causes (OR=1.35); or side effects (OR=1.03) between aripiprazole and the pooled antipsychotics. Aripiprazole was inferior to the pooled antipsychotics in PANSS positive subscale scores (SMD=0.17) and discontinuation because of inefficacy (OR=2.21, NNH=11). However, aripiprazole had fewer side effects compared with the pooled antipsychotics (OR=0.21, NNH=20 for one or more side effects), including fatigue (OR=0.22, NNH=8), hyperprolactinemia (OR=0.00, NNH=1), extrapyramidal symptoms (OR=0.46, NNH=6), and weight gain (OR=0.36, NNH=7). Moreover, aripiprazole was associated with lower total cholesterol (SMD=-0.20) and triglyceride (SMD=-0.17) levels and body weight (SMD=-0.20) compared with the pooled antipsychotics. Conclusion: Although the discontinuation rate associated with inefficacy was higher with aripiprazole than with the pooled antipsychotics, aripiprazole was associated with a lower risk of hyperprolactinemia and metabolic and extrapyramidal symptoms compared with the pooled antipsychotics.
  • Shinji Matsunaga, Taro Kishi, Nakao Iwata
    The international journal of neuropsychopharmacology 18(5) 1-11 2014年12月28日  査読有り
    BACKGROUND: We performed an updated meta-analysis of randomized controlled trials of combination therapy with cholinesterase inhibitors and memantine in patients with Alzheimer's disease. METHODS: We reviewed cognitive function, activities of daily living, behavioral disturbance, global assessment, discontinuation rate, and individual side effects. RESULTS: Seven studies (total n=2182) were identified. Combination therapy significantly affected behavioral disturbance scores (standardized mean difference=-0.13), activity of daily living scores (standardized mean difference=-0.10), and global assessment scores (standardized mean difference=-0.15). In addition, cognitive function scores (standardized mean difference=-0.13, P=.06) exhibited favorable trends with combination therapy. The effects of combination therapy were more significant in the moderate-to-severe Alzheimer's disease subgroup in terms of all efficacy outcome scores. The discontinuation rate was similar in both groups, and there were no significant differences in individual side effects. CONCLUSIONS: Combination therapy was beneficial for the treatment of moderate-to-severe Alzheimer's disease in terms of cognition, behavioral disturbances, activities of daily living, and global assessment was well tolerated.
  • Yoshio Yamanouchi, Tsuruhei Sukegawa, Ataru Inagaki, Toshiya Inada, Takashi Yoshio, Reiji Yoshimura, Nakao Iwata
    The international journal of neuropsychopharmacology 18(5) 2014年12月11日  査読有り
    BACKGROUND: Polypharmacy for schizophrenia treatment is not justified by the available clinical evidence. We evaluated a treatment reduction approach that reduces the dose and number of antipsychotic medications simultaneously prescribed to patients. METHODS: In a randomized open study of the Safe Correction of Antipsychotic Polypharmacy and High-Dose Prescriptions program funded by the Japanese Ministry of Health, Labour, and Welfare, we evaluated a drug reduction method consisting of a dose reduction intervention performed on 163 patients with schizophrenia for twelve or 24 weeks. One antipsychotic medication was removed each week from each patient's treatment regimen by reducing the dose by 0 to 50 chlorpromazine equivalents. Data on health-related indices of quality of life, clinical symptoms, and risk of side effects were analyzed using a two-way repeated-measures mixed linear model. RESULTS: Despite a 23% reduction in antipsychotic dose, no differences in outcomes were observed between the dose reduction and observation groups (effect size = 0.001 - 0.085, P = .24-.97), despite high statistical power (1-β = 0.48-0.97). The findings are limited by the nonuniformity of the participants' treatment history, duration, and dose reduction amount. Dose reduction protocol patients exhibited no difference in psychotic symptoms or adverse events compared with the observation group. CONCLUSIONS: Importantly, the low dropout rate in our study (6.9% of participants withdrew because of patient factors and 23.8% for all secondary reasons) indicates that our "slowly" method is well tolerated. We hope that this approach will result in therapeutic improvements.
  • Taro Kishi, Yuki Matsuda, Nakao Iwata
    Asia-Pacific psychiatry : official journal of the Pacific Rim College of Psychiatrists 6(4) 462-462 2014年12月  査読有り
  • Semanti Mukherjee, Saurav Guha, Masashi Ikeda, Nakao Iwata, Anil K Malhotra, Itsik Pe'er, Ariel Darvasi, Todd Lencz
    Human molecular genetics 23(22) 6088-95 2014年11月15日  査読有り
    Genome-wide association studies (GWAS) in schizophrenia have focused on additive allelic effects to identify disease risk loci. In order to examine potential recessive effects, we applied a novel approach to identify regions of excess homozygosity in an ethnically homogenous cohort: 904 schizophrenia cases and 1640 controls drawn from the Ashkenazi Jewish (AJ) population. Genome-wide examination of runs of homozygosity identified an excess in cases localized to the major histocompatibility complex (MHC). To refine this signal, we used the recently developed GERMLINE algorithm to identify chromosomal segments shared identical-by-descent (IBD) and compared homozygosity at such segments in cases and controls. We found a significant excess of homozygosity in schizophrenia cases compared with controls in the MHC (P-value = 0.003). An independent replication cohort of 548 schizophrenia cases from Japan and 542 matched healthy controls demonstrated similar effects. The strongest case-control recessive effects (P = 8.81 × 10(-8)) were localized to a 53-kb region near HLA-A, in a segment encompassing three poorly annotated genes, TRIM10, TRIM15 and TRIM40. At the same time, an adjacent segment in the Class I MHC demonstrated clear additive effects on schizophrenia risk, demonstrating the complexity of association in the MHC and the ability of our IBD approach to refine localization of broad signals derived from conventional GWAS. In sum, homozygosity in the classical MHC region appears to convey significant risk for schizophrenia, consistent with the ecological literature suggesting that homozygosity at the MHC locus may be associated with vulnerability to disease.
  • Yoshitaka Inui, Hiroshi Toyama, Yuta Manabe, Masayoshi Sarai, Nakao Iwata
    Annals of nuclear medicine 28(8) 796-804 2014年10月  査読有り
    OBJECTIVE: This study aimed to compare the diagnostic value of (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy, N-isopropyl-p[(123)I]iodoamphetamine (IMP) brain perfusion single-photon emission computed tomography (SPECT), and brain magnetic resonance imaging (MRI) voxel-based morphometry (VBM) for the differentiation of dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). METHODS: Thirty-five and 34 patients with probable DLB and probable AD, respectively, were enrolled. All patients underwent (123)I-MIBG myocardial scintigraphy, (123)I-IMP brain perfusion SPECT, and brain MRI. For (123)I-MIBG imaging, we calculated early and delayed heart-to-mediastinum (H/M) uptake ratios. Three-dimensional stereotactic surface projections (3D-SSP) were used to analyze the results of (123)I-IMP SPECT. VBM with statistical parametric mapping 8 plus diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) was used to analyze the brain MRI data. RESULTS: The area under the receiver operating characteristic curves (AUC) for discriminating DLB and AD was highest (0.882) for the delayed H/M ratio on (123)I-MIBG scintigraphy. AUC for z-score measurement in the occipital lobe was 0.818 and that for the extent of gray matter (GM) atrophy in the whole brain was 0.788. AUC for the combination of 3D-SSP and VBM analysis was 0.836. The respective sensitivities and specificities for distinguishing DLB from AD were 97.1 and 100 % for the delayed H/M ratio using (123)I-MIBG scintigraphy; 88.6 and 73.5 % for the occipital lobe z-score using 3D-SSP analysis; 85.7 and 64.7 % for the extent of whole brain GM atrophy using voxel-based MRI morphometry; and 91.4 and 76.5 % for the combination of 3D-SSP analysis and VBM. CONCLUSIONS: (123)I-MIBG myocardial scintigraphy was superior to brain perfusion SPECT and brain MRI using an advanced statistical technique to differentiate DLB and AD.
  • Hashimoto R, Ikeda M, Yamashita F, Ohi K, Yamamori H, Yasuda Y, Fujimoto M, Fukunaga M, Nemoto K, Takahashi T, Ochigi M, Onitsuka T, Yamasue H, Matsuo K, Iidaka T, Iwata N, Suzuki M, Takeda M, Kasai K, Ozaki N
    4(e472) e472 2014年10月  査読有り
  • Kazuto Oya, Taro Kishi, Nakao Iwata
    Human psychopharmacology 29(5) 483-91 2014年9月  査読有り
    OBJECTIVE: This study aimed to perform a comprehensive meta-analysis of minocycline augmentation therapy in patients with schizophrenia receiving antipsychotic agents. METHODS: Data published up to 2 June 2014 were obtained from the PubMed, PsycINFO, Google Scholar, and Cochrane Library databases.We conducted a systematic review and meta-analysis of patient data from randomized controlled trials (RCTs) comparing minocycline with placebo. Relative risk (RR), standardized mean difference (SMD), and 95% confidence intervals were calculated. RESULTS: We included four RCTs. The total sample included 330 patients. Minocycline was superior to placebo for decreasing Positive and Negative Syndrome Scale (PANSS) total scores (SMD=0.70), PANSS negative subscale scores (SMD=0.86), and PANSS general subscale scores (SMD=-0.50) but was not different from placebo for PANSS positive subscale scores (SMD=0.26) and depressive symptoms (SMD=0.28). Minocycline was equivalent to placebo for all-cause discontinuation (RR=1.10), discontinuation due to inefficacy (RR=0.42), discontinuation due to adverse events (RR = 1.56), and discontinuation due to death (RR = 3.18). Minocycline was superior to placebo for extrapyramidal side-effect scores (SMD=0.32). CONCLUSIONS: Minocycline may improve the psychopathology of schizophrenia, especially the negative symptoms, and seems to be well tolerated.
  • Kazutaka Ohi, Ryota Hashimoto, Masashi Ikeda, Fumio Yamashita, Masaki Fukunaga, Kiyotaka Nemoto, Takashi Ohnishi, Hidenaga Yamamori, Yuka Yasuda, Michiko Fujimoto, Satomi Umeda-Yano, Yoshiyuki Watanabe, Nakao Iwata, Daniel R Weinberger, Masatoshi Takeda
    Cortex; a journal devoted to the study of the nervous system and behavior 58 23-6 2014年9月  査読有り
  • Chenyao Wang, Takayoshi Koide, Hiroki Kimura, Shohko Kunimoto, Akira Yoshimi, Yukako Nakamura, Itaru Kushima, Masahiro Banno, Naoko Kawano, Yuto Takasaki, Jingrui Xing, Yukihiro Noda, Akihiro Mouri, Branko Aleksic, Masashi Ikeda, Takashi Okada, Tetsuya Iidaka, Toshiya Inada, Nakao Iwata, Norio Ozaki
    Schizophrenia research 157(1-3) 149-56 2014年8月  査読有り
    The ubiquitin ligase F-box protein 45 (FBXO45) is critical for synaptogenesis, neuronal migration, and synaptic transmission. FBXO45 is included in the 3q29 microdeletion region that confers a significant risk for schizophrenia, as shown by rare structural variant studies. Thus, FBXO45 is considered a prominent candidate for mediating schizophrenia pathogenesis. Here, we investigated rare, deleterious single nucleotide variants (SNVs) as well as small insertions and deletions (INDELs) in FBXO45 that may contribute to schizophrenia susceptibility. Using Sanger sequencing, we performed mutation screening in FBXO45 exon regions in 337 schizophrenia patients. Novel missense or nonsense variants were followed up with a genetic association study in an independent sample set of 601 schizophrenia patients and 916 controls, a case report for assessing the clinical consequence of the mutations, a pedigree study for measuring mutation inheritance in the proband's family, bioinformatics analyses for evaluating mutation effect on protein structure and function, and mRNA expression analysis for examining mutation transcriptional influence on FBXO45 expression. One heterozygous, novel, and rare missense mutation (R108C) was identified in a single schizophrenia patient and in his healthy mother. At age 20, this patient was diagnosed with paranoid schizophrenia and carried some clinical features of 3q29 deletion phenotypes, including premorbid IQ decline. With follow-up genotyping, this mutation was not found in either the schizophrenia group (0/601) or the healthy control group (0/916). Bioinformatics analyses predicted that R108C probably pathologically impacted the structure and function of the FBXO45 protein. The relative expression of FBXO45 in SCZ case with R108C mutation was relatively low when compared to 50 schizophrenia patients and 52 healthy controls. The R108C mutation in FBXO45 is a rare variant with a modest effect on schizophrenia risk that may disrupt the structure and function of the FBXO45 protein. Our findings also suggest that FBXO45 may be a new attractive candidate gene for schizophrenia.
  • Chiaki Kawanishi, Tohru Aruga, Naoki Ishizuka, Naohiro Yonemoto, Kotaro Otsuka, Yoshito Kamijo, Yoshiro Okubo, Katsumi Ikeshita, Akio Sakai, Hitoshi Miyaoka, Yoshie Hitomi, Akihiro Iwakuma, Toshihiko Kinoshita, Jotaro Akiyoshi, Naoshi Horikawa, Hideto Hirotsune, Nobuaki Eto, Nakao Iwata, Mototsugu Kohno, Akira Iwanami, Masaru Mimura, Takashi Asada, Yoshio Hirayasu
    The lancet. Psychiatry 1(3) 193-201 2014年8月  査読有り
    BACKGROUND: Non-fatal suicide attempt is the most important risk factor for later suicide. Emergency department visits for attempted suicide are increasingly recognised as opportunities for intervention. However, no strong evidence exists that any intervention is effective at preventing repeated suicide attempts. We aimed to investigate whether assertive case management can reduce repetition of suicide attempts in people with mental health problems who had attempted suicide and were admitted to emergency departments. METHODS: In this multicentre, randomised controlled trial in 17 hospital emergency departments in Japan, we randomly assigned people aged 20 years and older with mental health problems who had attempted suicide to receive either assertive case management (based on psychiatric diagnoses, social risks, and needs of the patients) or enhanced usual care (control), using an internet-based randomisation system. Interventions were provided until the end of the follow-up period (ie, at least 18 months and up to 5 years). Outcome assessors were masked to group allocation, but patients and case managers who provided the interventions were not. The primary outcome was the incidence of first recurrent suicidal behaviour (attempted suicide or completed suicide); secondary outcomes included completed suicide and all-cause mortality. This study is registered at ClinicalTrials.gov (NCT00736918) and UMIN-CTR (C000000444). FINDINGS: Between July 1, 2006, and Dec 31, 2009, 914 eligible participants were randomly assigned, 460 to the assertive case management group and 456 to the enhanced usual care group. We noted no significant difference in incidence of first recurrent suicidal behaviour between the assertive case management group and the enhanced usual care group over the full study period (log-rank p=0·258). Because the proportional hazards assumption did not hold, we did ad-hoc analyses for cumulative incidence of the primary outcome at months 1, 3, 6, 12, and 18 after randomisation, adjusting for multiplicity with the Bonferroni method. Assertive case management significantly reduced the incidence of first recurrent suicidal behaviour up to the 6-month timepoint (6-month risk ratio 0·50, 95% CI 0·32-0·80; p=0·003), but not at the later timepoints. Prespecified subgroup analyses showed that the intervention had a greater effect in women (up to 18 months), and in participants younger than 40 years and those with a history of previous suicide attempts (up to 6 months). We did not identify any differences between the intervention and control groups for completed suicide (27 [6%] of 460 vs 30 [7%] of 454, log-rank p=0·660) or all-cause mortality (46 [10%] of 460 vs 42 [9%] of 454, log-rank p=0·698). INTERPRETATION: Our results suggest that assertive case management is feasible in real-world clinical settings. Although it was not effective at reducing the incidence of repetition of suicide attempts in the long term, the results of our ad-hoc analyses suggested that it was effective for up to 6 months. This finding should be investigated in future research. FUNDING: The Ministry of Health, Labour, and Welfare of Japan.
  • Takeo Saito, Kenji Kondo, Yoshimi Iwayama, Ayu Shimasaki, Branko Aleksic, Kazuo Yamada, Tomoko Toyota, Eiji Hattori, Kosei Esaki, Hiroshi Ujike, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Norio Ozaki, Masashi Ikeda, Nakao Iwata
    American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 165B(5) 421-7 2014年7月  査読有り
    Recent genome-wide association studies (GWASs) of schizophrenia (SCZ) identified several susceptibility genes and suggested shared genetic components between SCZ and bipolar disorder (BD). We conducted a genetic association study of single nucleotide polymorphisms (SNPs) selected according to previous SCZ GWAS targeting psychotic disorders (SCZ and BD) in the Japanese population. Fifty-one SNPs were analyzed in a two-stage design using first-set screening samples (all SNPs: 1,032 SCZ, 1,012 BD, and 993 controls) and second-set replication samples ("significant" SNPs in the first-set screening analysis: 1,808 SCZ, 821 BD, and 2,321 controls). We assessed allelic associations between the selected SNPs and the three phenotypes (SCZ, BD, and "psychosis" [SCZ + BD]). Nine SNPs revealed nominal association signals for all comparisons (P(uncorrected) < 0.05), of which two SNPs located in the major histocompatibility complex region (rs7759855 in zinc finger and SCAN domain containing 31 [ZSCAN31] and rs1736913 in HLA-F antisense RNA1 [HLA-F-AS1]) were further assessed in the second-set replication samples. The associations were confirmed for rs7759855 (P(corrected) = 0.026 for psychosis; P(corrected) = 0.032 for SCZ), although the direction of effect was opposite to that in the original GWAS of the Chinese population. Finally, a meta-analysis was conducted using our two samples and using our data and data from Psychiatric GWAS Consortium (PGC), which have shown the same direction of effect. SNP in ZSCAN31 (rs7759855) had the strongest association with the phenotypes (best P = 6.8 × 10(-5) for psychosis: present plus PGC results). These data support shared risk SNPs between SCZ and BD in the Japanese population and association between MHC and psychosis.
  • Stephan Ripke, Benjamin M. Neale, Aiden Corvin, James T. R. Walters, Kai-How Farh, Peter A. Holmans, Phil Lee, Brendan Bulik-Sullivan, David A. Collier, Hailiang Huang, Tune H. Pers, Ingrid Agartz, Esben Agerbo, Margot Albus, Madeline Alexander, Farooq Amin, Silviu A. Bacanu, Martin Begemann, Richard A. Belliveau, Judit Bene, Sarah E. Bergen, Elizabeth Bevilacqua, Tim B. Bigdeli, Donald W. Black, Richard Bruggeman, Nancy G. Buccola, Randy L. Buckner, William Byerley, Wiepke Cahn, Guiqing Cai, Dominique Campion, Rita M. Cantor, Vaughan J. Carr, Noa Carrera, Stanley V. Catts, Kimberly D. Chambert, Raymond C. K. Chan, Ronald Y. L. Chen, Eric Y. H. Chen, Wei Cheng, Eric F. C. Cheung, Siow Ann Chong, C. Robert Cloninger, David Cohen, Nadine Cohen, Paul Cormican, Nick Craddock, James J. Crowley, David Curtis, Michael Davidson, Kenneth L. Davis, Franziska Degenhardt, Jurgen Del Favero, Ditte Demontis, Dimitris Dikeos, Timothy Dinan, Srdjan Djurovic, Gary Donohoe, Elodie Drapeau, Jubao Duan, Frank Dudbridge, Naser Durmishi, Peter Eichhammer, Johan Eriksson, Valentina Escott-Price, Laurent Essioux, Ayman H. Fanous, Martilias S. Farrell, Josef Frank, Lude Franke, Robert Freedman, Nelson B. Freimer, Marion Friedl, Joseph I. Friedman, Menachem Fromer, Giulio Genovese, Lyudmila Georgieva, Ina Giegling, Paola Giusti-Rodriguez, Stephanie Godard, Jacqueline I. Goldstein, Vera Golimbet, Srihari Gopal, Jacob Gratten, Lieuwe de Haan, Christian Hammer, Marian L. Hamshere, Mark Hansen, Thomas Hansen, Vahram Haroutunian, Annette M. Hartmann, Frans A. Henskens, Stefan Herms, Joel N. Hirschhorn, Per Hoffmann, Andrea Hofman, Mads V. Hollegaard, David M. Hougaard, Masashi Ikeda, Inge Joa, Antonio Julia, Rene S. Kahn, Luba Kalaydjieva, Sena Karachanak-Yankova, Juha Karjalainen, David Kavanagh, Matthew C. Keller, James L. Kennedy, Andrey Khrunin, Yunjung Kim, Janis Klovins, James A. Knowles, Bettina Konte, Vaidutis Kucinskas, Zita Ausrele Kucinskiene, Hana Kuzelova-Ptackova, Anna K. Kahler, Claudine Laurent, Jimmy Lee Chee Keong, S. Hong Lee, Sophie E. Legge, Bernard Lerer, Miaoxin Li, Tao Li, Kung-Yee Liang, Jeffrey Lieberman, Svetlana Limborska, Carmel M. Loughland, Jan Lubinski, Jouko Lonnqvist, Milan Macek, Patrik K. E. Magnusson, Brion S. Maher, Wolfgang Maier, Jacques Mallet, Sara Marsal, Manuel Mattheisen, Morten Mattingsdal, Robert W. McCarley, Colm McDonald, Andrew M. McIntosh, Sandra Meier, Carin J. Meijer, Bela Melegh, Ingrid Melle, Raquelle I. Mesholam-Gately, Andres Metspalu, Patricia T. Michie, Lili Milani, Vihra Milanova, Younes Mokrab, Derek W. Morris, Ole Mors, Kieran C. Murphy, Robin M. Murray, Inez Myin-Germeys, Bertram Mueller-Myhsok, Mari Nelis, Igor Nenadic, Deborah A. Nertney, Gerald Nestadt, Kristin K. Nicodemus, Liene Nikitina-Zake, Laura Nisenbaum, Annelie Nordin, Eadbhard O'Callaghan, Colm O'Dushlaine, F. Anthony O'Neill, Sang-Yun Oh, Ann Olincy, Line Olsen, Jim Van Os, Christos Pantelis, George N. Papadimitriou, Sergi Papiol, Elena Parkhomenko, Michele T. Pato, Tiina Paunio, Milica Pejovic-Milovancevic, Diana O. Perkins, Olli Pietilainen, Jonathan Pimm, Andrew J. Pocklington, John Powell, Alkes Price, Ann E. Pulver, Shaun M. Purcell, Digby Quested, Henrik B. Rasmussen, Abraham Reichenberg, Mark A. Reimers, Alexander L. Richards, Joshua L. Roffman, Panos Roussos, Douglas M. Ruderfer, Veikko Salomaa, Alan R. Sanders, Ulrich Schall, Christian R. Schubert, Thomas G. Schulze, Sibylle G. Schwab, Edward M. Scolnick, Rodney J. Scott, Larry J. Seidman, Jianxin Shi, Engilbert Sigurdsson, Teimuraz Silagadze, Jeremy M. Silverman, Kang Sim, Petr Slominsky, Jordan W. Smoller, Hon-Cheong So, Chris C. A. Spencer, Eli A. Stahl, Hreinn Stefansson, Stacy Steinberg, Elisabeth Stogmann, Richard E. Straub, Eric Strengman, Jana Strohmaier, T. Scott Stroup, Mythily Subramaniam, Jaana Suvisaari, Dragan M. Svrakic, Jin P. Szatkiewicz, Erik Soderman, Srinivas Thirumalai, Draga Toncheva, Sarah Tosato, Juha Veijola, John Waddington, Dermot Walsh, Dai Wang, Qiang Wang, Bradley T. Webb, Mark Weiser, Dieter B. Wildenauer, Nigel M. Williams, Stephanie Williams, Stephanie H. Witt, Aaron R. Wolen, Emily H. M. Wong, Brandon K. Wormley, Hualin Simon Xi, Clement C. Zai, Xuebin Zheng, Fritz Zimprich, Naomi R. Wray, Kari Stefansson, Peter M. Visscher, Rolf Adolfsson, Ole A. Andreassen, Douglas H. R. Blackwood, Elvira Bramon, Joseph D. Buxbaum, Anders D. Borglum, Sven Cichon, Ariel Darvasi, Enrico Domenici, Hannelore Ehrenreich, Tonu Esko, Pablo V. Gejman, Michael Gill, Hugh Gurling, Christina M. Hultman, Nakao Iwata, Assen V. Jablensky, Erik G. Jonsson, Kenneth S. Kendler, George Kirov, Jo Knight, Todd Lencz, Douglas F. Levinson, Qingqin S. Li, Jianjun Liu, Anil K. Malhotra, Steven A. McCarroll, Andrew McQuillin, Jennifer L. Moran, Preben B. Mortensen, Bryan J. Mowry, Markus M. Noethen, Roel A. Ophoff, Michael J. Owen, Aarno Palotie, Carlos N. Pato, Tracey L. Petryshen, Danielle Posthuma, Marcella Rietschel, Brien P. Riley, Dan Rujescu, Pak C. Sham, Pamela Sklar, David St Clair, Daniel R. Weinberger, Jens R. Wendland, Thomas Werge, Mark J. Daly, Patrick F. Sullivan, Michael C. O'Donovan
    NATURE 511(7510) 421-+ 2014年7月  査読有り
    Schizophrenia is a highly heritable disorder. Genetic risk is conferred by a large number of alleles, including common alleles of small effect that might be detected by genome-wide association studies. Here we report a multi-stage schizophrenia genome-wide association study of up to 36,989 cases and 113,075 controls. We identify 128 independent associations spanning 108 conservatively defined loci that meet genome-wide significance, 83 of which have not been previously reported. Associations were enriched among genes expressed in brain, providing biological plausibility for the findings. Many findings have the potential to provide entirely new insights into aetiology, but associations at DRD2 and several genes involved in glutamatergic neurotransmission highlight molecules of known and potential therapeutic relevance to schizophrenia, and are consistent with leading pathophysiological hypotheses. Independent of genes expressed in brain, associations were enriched among genes expressed in tissues that have important roles in immunity, providing support for the speculated link between the immune system and schizophrenia.
  • Tsutomu Takahashi, Yumiko Nakamura, Yukako Nakamura, Branko Aleksic, Yoichiro Takayanagi, Atsushi Furuichi, Mikio Kido, Mihoko Nakamura, Daiki Sasabayashi, Masashi Ikeda, Kyo Noguchi, Kozo Kaibuchi, Nakao Iwata, Norio Ozaki, Michio Suzuki
    Progress in neuro-psychopharmacology & biological psychiatry 51 166-71 2014年6月3日  査読有り
    An altered sulcogyral pattern in the orbitofrontal cortex (OFC) has been implicated in schizophrenia as a possible marker of abnormal neurodevelopment, while its genetic mechanism remains unknown. This magnetic resonance imaging study investigated the relationship between the polymorphism of YWHAE (rs28365859), a gene encoding 14-3-3epsilon that is a Disrupted-in-Schizophrenia 1 (DISC1)-interacting molecule associated with neuronal development, and the OFC subtypes of the 'H-shaped' sulcus (Types I, II, and III) in a Japanese sample of 72 schizophrenia patients and 86 healthy controls. The schizophrenia patients had significantly increased Type III (p = 0.004) and decreased Type I (p = 0.013) expression on the right hemisphere compared to the controls. The subjects carrying the protective C allele showed a decrease in Type III (p = 0.005) and an increase in Type I (p = 0.017) compared to the G allele homozygotes, especially for the healthy subjects in the left hemisphere. These results suggest a possible role for the YWHAE genotype in the early development of the OFC sulcogyral pattern, but its effect alone is not likely to explain the altered sulcogyral pattern in schizophrenia.
  • Masashi Ikeda, Kenji Kondo, Nakao Iwata
    The New England journal of medicine 370(19) 1856-7 2014年5月8日  査読有り
  • Tokiko Morita, Koji Senzaki, Ryoko Ishihara, Kazunori Umeda, Nakao Iwata, Taku Nagai, Hirotake Hida, Toshitaka Nabeshima, Kazunori Yukawa, Norio Ozaki, Yukihiro Noda
    Human psychopharmacology 29(3) 280-6 2014年5月  査読有り
    OBJECTIVE: We attempted to investigate whether dehydroepiandrosterone sulfate (DHEA-S) levels are associated with remission of major depressive disorder by assessing scores on the 17-Item Structured Interview Guide for the Hamilton Depression before and after antidepressant treatment. METHODS: Plasma DHEA-S levels in 24 patients diagnosed with major depressive disorder on the basis of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (text revision) before and after antidepressant treatment, and 24 healthy, gender-matched, and age-matched controls were measured using a radioimmunoassay kit. RESULTS: Plasma DHEA-S levels in patients were significantly higher than those in healthy controls. In patients who achieved remission after antidepressant treatment, plasma DHEA-S levels significantly declined compared with the levels before treatment. A significant correlation was observed between changes in DHEA-S levels and Absence of Depressive and Anxious Mood scores, which are calculated from the 2-Item Structured Interview Guide for the Hamilton Depression rating as follows: severity of depressive mood and anxiety in patients before and after antidepressant treatment. CONCLUSIONS: These findings suggest that plasma DHEA-S levels can be used as a putative indicator of the state of remission in patients with major depressive disorder. Copyright © 2014 John Wiley & Sons, Ltd.
  • Tsuruhei Sukegawa, Ataru Inagaki, Yoshio Yamanouchi, Toshiya Inada, Takashi Yoshio, Reiji Yoshimura, Nakao Iwata
    BMC psychiatry 14 103-103 2014年4月7日  査読有り
    BACKGROUND: In Japan, combination therapy with high doses of antipsychotic drugs is common, but as a consequence, many patients with schizophrenia report extrapyramidal and autonomic nervous system side effects. To resolve this, we proposed a method of safety correction of high dose antipsychotic polypharmacy (the SCAP method), in which the initial total dose of all antipsychotic drugs is calculated and converted to a chlorpromazine equivalent (expressed as milligrams of chlorpromazine, mg CP). The doses of low-potency antipsychotic drugs are then reduced by ≤ 25 mg CP/week, and the doses of high-potency antipsychotics are decreased at a rate of ≤ 50 mg CP/week. Although a randomized, case-controlled comparative study has demonstrated the safety of this method, the number of participants was relatively small and its results required further validation. In this study of the SCAP method, we aimed to substantially increase the number of participants. METHODS/DESIGN: The participants were in- or outpatients treated with two or more antipsychotics at doses of 500-1,500 mg CP/day. Consenting participants were randomized into control and dose reduction groups. In the control group, patients continued with their normal regimen for 3 months without a dose change before undergoing the SCAP protocol. The dose reduction group followed the SCAP strategy over 3-6 months with a subsequent 3-month follow-up period. Outcome measures were measured at baseline and then at 3-month intervals, and included clinical symptoms measured on the Manchester scale, the extent of extrapyramidal and autonomic side effects, and quality of life using the Euro QOL scale. We also measured blood drug concentrations and drug efficacy-associated biochemical parameters. The Brief Assessment of Cognition in Schizophrenia, Japanese version, was also undertaken in centers where it was available. DISCUSSION: The safety and efficacy of the SCAP method required further validation in a large randomized trial. The design of this study aimed to address some of the limitations of the previous case-controlled study, to build a more robust evidence base to assist clinicians in their efforts to reduce potentially harmful polypharmacy in this vulnerable group of patients. TRIAL REGISTRATION: UMIN Clinical Trials Registry 000004511.
  • Taro Kishi, Yasuhisa Fukuo, Masatsugu Moriwaki, Nakao Iwata, Hikaru Hori, Reiji Yoshimura, Asuka Katsuki, Atsuko Ikenouchi-Sugita, Kiyokazu Atake, Wakako Umene-Nakano, Jun Nakamura, Yasuhiro Kaneda, Kiyoshi Fujita
    Psychiatry research 215(3) 803-5 2014年3月30日  査読有り
  • Jennifer Gladys Mulle, Ann E Pulver, John A McGrath, Paula S Wolyniec, Anne F Dodd, David J Cutler, Jonathan Sebat, Dheeraj Malhotra, Gerald Nestadt, Donald F Conrad, Matthew Hurles, Chris P Barnes, Masashi Ikeda, Nakao Iwata, Douglas F Levinson, Pablo V Gejman, Alan R Sanders, Jubao Duan, Adele A Mitchell, Inga Peter, Pamela Sklar, Colm T O'Dushlaine, Detelina Grozeva, Michael C O'Donovan, Michael J Owen, Christina M Hultman, Anna K Kähler, Patrick F Sullivan, George Kirov, Stephen T Warren
    Biological psychiatry 75(5) 371-7 2014年3月1日  査読有り
    BACKGROUND: Several copy number variants (CNVs) have been implicated as susceptibility factors for schizophrenia (SZ). Some of these same CNVs also increase risk for autism spectrum disorders, suggesting an etiologic overlap between these conditions. Recently, de novo duplications of a region on chromosome 7q11.23 were associated with autism spectrum disorders. The reciprocal deletion of this region causes Williams-Beuren syndrome. METHODS: We assayed an Ashkenazi Jewish cohort of 554 SZ cases and 1014 controls for genome-wide CNV. An excess of large rare and de novo CNVs were observed, including a 1.4 Mb duplication on chromosome 7q11.23 identified in two unrelated patients. To test whether this 7q11.23 duplication is also associated with SZ, we obtained data for 14,387 SZ cases and 28,139 controls from seven additional studies with high-resolution genome-wide CNV detection. We performed a meta-analysis, correcting for study population of origin, to assess whether the duplication is associated with SZ. RESULTS: We found duplications at 7q11.23 in 11 of 14,387 SZ cases with only 1 in 28,139 control subjects (unadjusted odds ratio 21.52, 95% confidence interval: 3.13-922.6, p value 5.5 × 10(-5); adjusted odds ratio 10.8, 95% confidence interval: 1.46-79.62, p value .007). Of three SZ duplication carriers with detailed retrospective data, all showed social anxiety and language delay premorbid to SZ onset, consistent with both human studies and animal models of the 7q11.23 duplication. CONCLUSIONS: We have identified a new CNV associated with SZ. Reciprocal duplication of the Williams-Beuren syndrome deletion at chromosome 7q11.23 confers an approximately tenfold increase in risk for SZ.
  • Taro Kishi, Tomohiko Mukai, Yuki Matsuda, Nakao Iwata
    Neuromolecular medicine 16(1) 61-9 2014年3月  査読有り
    Double-blinded, randomized, placebo-control trials of selective serotonin 3 receptor antagonists (5-HT3R-ANTs) for schizophrenia have differed in outcome. This meta-analysis tests the hypothesis that 5-HT3R-ANTs are effective for the treatment for schizophrenia. We searched PubMed, the Cochrane Library database, and PsycINFO up to June 15, 2013. We conducted a systematic review and meta-analysis of individual patient data from randomized controlled trials comparing 5-HT3R-ANTs add-on therapy with placebo. The risk ratio (RR), 95 % confidence intervals (CI), and standardized mean difference (SMD) were calculated. A random-effects model was used. Six studies (total n = 311) were identified. These included one granisetron plus risperidone study, one ondansetron plus risperidone study, one ondansetron plus haloperidol, and three tropisetron plus risperidone studies. The statistically significant effects of 5-HT3R-ANTs add-on therapy on Positive and Negative Syndrome Scale (PANSS) total scores were SMD = -1.03, CI = -1.70 to -0.36, p = 0.003 (I (2) = 82 %, 5 studies, n = 261); on negative scores were SMD = -1.10, CI = -1.82 to -0.39, p = 0.002 (I (2) = 84 %, 5 studies, n = 261); and on PANSS general scores were SMD = -0.70, CI = -1.23 to -0.17, p = 0.01 (I (2) = 73 %, 5 studies, n = 261). However, 5-HT3R-ANTs add-on therapy was not superior to placebo in PANSS positive scores (SMD = -0.12, p = 0.33). Dropout due to all cause (RR = 0.80, p = 0.50), inefficacy (RR = 0.76, p = 0.65), or adverse events (RR = 0.84, p = 0.75) was similar in both groups. Constipation occurred significantly more often with 5-HT3R-ANTs than placebo (RR = 2.05, CI = 1.07-3.91, p = 0.03, NNH = 11, p = 0.02). 5-HT3R-ANTs add-on therapy is more beneficial on the psychopathology (especially negative symptoms) than controls in patients with schizophrenia, and 5-HT3R-ANTs seem to be well-tolerated treatments.
  • Taro Kishi, Nakao Iwata
    The international journal of neuropsychopharmacology 17(2) 343-54 2014年2月  査読有り
    We examined whether noradrenergic and specific serotonergic antidepressants (NaSSAs: mirtazapine and mianserin), as augmentation therapy, have therapeutic potential for schizophrenia treatment. A systematic review was conducted of PubMed, Cochrane Library and PsycINFO in December 2012 and meta-analyses of double-blind, randomized placebo-controlled trials were performed. Standardized mean difference (SMD), risk ratio (RR), number-needed-to-treat (NNT), number-needed-to-harm (NNH) and 95% confidence intervals (CI) were calculated. Results were across 12 studies and 362 patients were included (mirtazapine: seven trials and 221 patients; mianserin: five trials and 141 patients). NaSSA augmentation therapy was superior to placebo in overall symptoms (S.M.D. = -0.75, CI -1.24 to -0.26, p = 0.003, N = 11, n = 301), negative symptoms (S.M.D. = -0.88, CI -1.41 to -0.34, p = 0.001, N = 9, n = 240) and response rate (RR = 0.71, CI 0.57-0.88, p = 0.002, NNT = 4, p<0.00001, N = 6, n = 163). There was no significant difference in positive symptoms, depressive symptoms or discontinuation rate between NaSSAs and placebo treatments. In addition, no patients who received NaSSAs developed worsening psychosis during the study. For individual NaSSAs, mirtazapine was superior to placebo in overall symptoms (S.M.D. = 0.98, CI = -1.74 to -0.22, p = 0.01, N = 7, n = 194), negative symptoms (S.M.D. = -1.25, CI -1.88 to -0.62, p = 0.0001, N = 6, n = 172) and response rate (RR = 0.70, p = 0.04, NNT = 4, p = 0.0004, N = 4, n = 119). Moreover, NaSSAs were associated with reduced akathisia score (p < 0.00001) and extrapyramidal symptom scales (p = 0.01). However, NaSSAs caused drowsiness/sedation/somnolence compared with placebo (RR = 3.52, p = 0.002, NNT = 6, p = 0.01, N = 8, n = 209). Our results indicate that NaSSA (especially mirtazapine) augmentation therapy improved overall and negative symptoms in patients with schizophrenia. Because the included studies were small, the results should be treated with caution.
  • Yuichi Esaki, Tsuyoshi Kitajima, Akiko Tsuchiya, Marina Hirose, Yumika Torii, Shiho Fujita, Nakao Iwata
    Psychiatry and clinical neurosciences 68(2) 167-167 2014年2月  査読有り
  • T. Lencz, E. Knowles, G. Davies, S. Guha, D. C. Liewald, J. M. Starr, S. Djurovic, I. Melle, K. Sundet, A. Christoforou, I. Reinvang, S. Mukherjee, Pamela DeRosse, A. Lundervold, V. M. Steen, M. John, T. Espeseth, K. Raikkonen, E. Widen, A. Palotie, J. G. Eriksson, I. Giegling, B. Konte, M. Ikeda, P. Roussos, S. Giakoumaki, K. E. Burdick, A. Payton, W. Ollier, M. Horan, G. Donohoe, D. Morris, A. Corvin, M. Gill, N. Pendleton, N. Iwata, A. Darvasi, P. Bitsios, D. Rujescu, J. Lahti, S. L. Hellard, M. C. Keller, O. A. Andreassen, I. J. Deary, D. C. Glahn, A. K. Malhotra
    MOLECULAR PSYCHIATRY 19(2) 168-174 2014年2月  査読有り
    It has long been recognized that generalized deficits in cognitive ability represent a core component of schizophrenia (SCZ), evident before full illness onset and independent of medication. The possibility of genetic overlap between risk for SCZ and cognitive phenotypes has been suggested by the presence of cognitive deficits in first-degree relatives of patients with SCZ; however, until recently, molecular genetic approaches to test this overlap have been lacking. Within the last few years, large-scale genome-wide association studies (GWAS) of SCZ have demonstrated that a substantial proportion of the heritability of the disorder is explained by a polygenic component consisting of many common single-nucleotide polymorphisms (SNPs) of extremely small effect. Similar results have been reported in GWAS of general cognitive ability. The primary aim of the present study is to provide the first molecular genetic test of the classic endophenotype hypothesis, which states that alleles associated with reduced cognitive ability should also serve to increase risk for SCZ. We tested the endophenotype hypothesis by applying polygenic SNP scores derived from a large-scale cognitive GWAS meta-analysis (similar to 5000 individuals from nine nonclinical cohorts comprising the Cognitive Genomics consorTium (COGENT)) to four SCZ case-control cohorts. As predicted, cases had significantly lower cognitive polygenic scores compared to controls. In parallel, polygenic risk scores for SCZ were associated with lower general cognitive ability. In addition, using our large cognitive meta-analytic data set, we identified nominally significant cognitive associations for several SNPs that have previously been robustly associated with SCZ susceptibility. Results provide molecular confirmation of the genetic overlap between SCZ and general cognitive ability, and may provide additional insight into pathophysiology of the disorder.
  • Yusuke Kajio, Kenji Kondo, Takeo Saito, Yoshimi Iwayama, Branko Aleksic, Kazuo Yamada, Tomoko Toyota, Eiji Hattori, Hiroshi Ujike, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Norio Ozaki, Masashi Ikeda, Nakao Iwata
    Journal of human genetics 59(1) 54-6 2014年1月  査読有り
    Several epidemiological and genetic studies have suggested that the risk of type II diabetes (T2D) is likely to overlap with the susceptibility to psychotic disorders such as schizophrenia (SCZ) and bipolar disorder (BD). In this study, we aimed to examine the association of single-nucleotide polymorphisms (SNPs) detected in previous T2D genome-wide association studies (GWAS) with SCZ, BD and psychosis (SCZ plus BD). A total of 37 SNPs were selected from the literature. A two-stage analysis was conducted using a first set of screening samples (total N=3037) and a second set of replication samples (N=4950). None of the SNPs showed a significant association to the screening samples after correction for multiple testing. To avoid type II error, we genotyped the top three SNPs in BCL11A, HMG20A and HNF4A showing associations with any of the phenotypes (Puncorrected <0.01) using independent samples to replicate the nominal associations. However, we were unable to find any significant associations based on the screening results (Puncorrected>0.05). Our findings did not support the shared genetic risk between T2D and psychotic disorders in the Japanese population. However, further replication using a larger sample size is required.
  • Tomohiko Mukai, Taro Kishi, Yuki Matsuda, Nakao Iwata
    Human psychopharmacology 29(1) 55-63 2014年1月  査読有り
    OBJECTIVE: This study is a meta-analysis of inositol as a treatment for depression and anxiety disorders. METHODS: PubMed, Cochrane Library database, and PsycINFO were searched up to 14 August 2013. A systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials (RCTs) were conducted comparing inositol for depressed or anxiety disorder patients. RESULTS: Seven RCTs in depression (two bipolar depression studies, one bipolar depression and major depressive disorder (MDD) study, two MDD studies, and two premenstrual dysphoric disorder (PMDD) studies) (n = 242) were identified. Four RCTs in anxiety disorders (two obsessive-compulsive disorder studies, one panic disorder study, and one posttraumatic stress disorder study) (n = 70) were also identified. There were no statistically significant effects of inositol on depressive, anxiety, and obsessive-compulsive symptoms and discontinuation (all-cause, side effects, and worsening psychiatric symptoms). However, inositol had marginally more responders in depression than placebo (p = 0.06), and inositol showed a trend towards superior efficacy for depressive symptoms in patients with PMDD (p = 0.07). Inositol marginally caused gastrointestinal upset compared with placebo (p = 0.06). CONCLUSIONS: Our results suggest that inositol may be beneficial for depressed patients, especially those with PMDD. The main limitation of this report is that a small number of studies were included in this meta-analysis.

MISC

 625

書籍等出版物

 6

共同研究・競争的資金等の研究課題

 15