研究者業績

大河内 智

オオコウチ トモ  (okochi tomo)

基本情報

所属
藤田医科大学 医学部 医学科 講師

J-GLOBAL ID
201801014490348440
researchmap会員ID
7000023621

論文

 57
  • Kohei Ninomiya, Takeo Saito, Tomo Okochi, Satoru Taniguchi, Ayu Shimasaki, Rei Aoki, Takeo Hata, Taisei Mushiroda, Tetsufumi Kanazawa, Masashi Ikeda, Nakao Iwata
    Translational psychiatry 11(1) 362-362 2021年7月7日  
    Pharmacogenetics/pharmacogenomics have enabled the detection of risk of human leukocyte antigen (HLA) variants for clozapine-induced agranulocytosis/granulocytopenia (CIAG). To apply this evidence to the clinical setting, we compared the cost-effectiveness of the proposed "HLA-guided treatment schedule" and the "current schedule" being used in Japan and the United Kingdom (UK) (absolute neutrophil count (ANC) cutoff at 1500/mm3); in the "HLA-guided treatment schedules," we considered a situation wherein the HLA test performed before clozapine initiation could provide "a priori information" by detecting patients harboring risk of HLA variants (HLA-B*59:01 and "HLA-B 158T/HLA-DQB1 126Q" for Japanese and Caucasian populations, respectively), a part of whom can then avoid CIAG onset (assumed 30% "prevention rate"). For the primary analysis, we estimated the incremental cost-effectiveness ratio (ICER) of "HLA-guided treatment schedule" and "current schedule" used in Japan and the UK, using a Markov model to calculate the cost and quality-adjusted life years (QALYs) over a 10-year time period. Furthermore, as an explorative analysis, we simulated several situations with various ANC cutoffs (1000/mm3 and 500/mm3) and plotted the cost/QALYs for each option to identify the best, or estimate the next best candidate option applicable in actual clinical settings. The primary probabilistic analysis showed that the "HLA-guided treatment schedule" was more cost effective than the "current schedule"; the ICER was £20,995 and £21,373 for the Japanese and the UK populations, respectively. Additional simulation revealed that the treatment option of ANC cutoff at 500/mm3 without HLA screening was the most cost-effective option; however, several options may be candidates to break away from the "current schedule" of ANC cutoff at 1500/mm3. Owing to its cost-effectiveness, we propose such pharmacogenetic-guided/pharmacogenomic-guided clozapine treatment for use in the real-world setting, which provides key information for optimization of clinical guidelines for high-risk patients for gradual change of clozapine treatment schedule under the safety consideration.
  • 青木 玲, 池田 匡志, 大河内 智, 齋藤 竹生, 谷口 賢, 二宮 光平, 芦澤 琢磨, 岩田 仲生
    日本神経精神薬理学会年会・日本生物学的精神医学会年会・日本精神薬学会総会・学術集会合同年会プログラム・抄録集 50回・42回・4回 217-217 2020年8月  
  • 池田 匡志, 斎藤 竹生, 大河内 智, 岩田 仲生
    実験医学 38(4) 556-559 2020年3月  
    代表的な精神疾患である双極性障害は遺伝要因が強く寄与する疾患であり、ゲノムワイド関連研究が導入されて以降、現在までに数十個の有意な関連領域が報告されている。そのなかでも、脂質代謝に重要な役割を示すfatty acid desaturase(FADS)遺伝子関連は、機能がきわめて明確な感受性遺伝子であり、この結果は双極性障害の脂質代謝異常仮説を支持するものである。事実、双極性障害患者でみられる脂質代謝異常(メタボリック症候群を含む)は、複数報告されており、その基盤となりうる結果とも言える。本稿では、双極性障害のゲノム研究を概説するとともに、この「双極性障害の脂質異常仮説」にも焦点を当て概説する。(著者抄録)
  • Kosei Esaki, Masashi Ikeda, Tomo Okochi, Satoru Taniguchi, Kohei Ninomiya, Ayu Shimasaki, Yasuyo Otsuka, Yoshiko Oda, Takaya Sakusabe, Keiko Mano, Takeo Saito, Nakao Iwata
    PloS one 15(10) e0240466 2020年  
    Depressive symptoms are a serious problem in workplaces. Hospital staff members, such as newly licensed registered nurses (NLRNs), are at particularly increased risk of these symptoms owing to their limited experience. Previous studies have shown that a brief program-based cognitive behavioral therapy program (CBP) can offer effective treatment. Here, we conducted a longitudinal observational study of 683 NLRNs (CBP group, n = 522; no-CBP group, n = 181) over a period of 1 year (six times surveys were done during this period). Outcomes were assessed on the basis of surveys that covered the Beck Depression Inventory-I (BDI). The independent variables were CBP attendance (CBP was conducted 3 months after starting work), personality traits, personal stressful life events, workplace adversity, and pre-CBP change in BDI in the 3 months before CBP (ΔBDIpre-CBP). All factors were included in Cox proportional hazards models with time-dependent covariates for depressive symptoms (BDI ≥10), and we reported hazard ratios (HRs). Based on this analysis, we detected that CBP was significantly associated with benefit for depressive symptoms in all NLRNs (Puncorrected = 0.0137, HR = 0.902). To identify who benefitted most from CBP, we conducted a subgroup analysis based on the change in BDI before CBP (ΔBDIpre-CBP). The strongest association was when BDI scores were low after starting work and increased before CBP (Puncorrected = 0.00627, HR = 0.616). These results are consistent with previous findings, and indicate that CBP may benefit the mental health of NLRNs. Furthermore, selective prevention based on the pattern of BDI change over time may be important in identifying who should be offered CBP first. Although CBP is generally effective for all nurses, such a selective approach may be most appropriate where cost-effectiveness is a prominent concern.
  • Taro Kishi, Yuki Matsuda, Shinji Matsunaga, Masatsugu Moriwaki, Yoichiro Otake, Kaku Akamatsu, Tomo Okochi, Shigeki Hirano, Toshihiko Funahashi, Momoko Okuda, Hideaki Tabuse, Kiyoshi Fujita, Nakao Iwata
    Neuropsychiatric Disease and Treatment 13 117-125 2017年1月6日  査読有り
    Objective: There are no direct comparisons between escitalopram and paroxetine controlled release in patients with major depressive disorder (MDD). Methods: We conducted a 24-week, rater-masked, randomized trial of escitalopram (5–20 mg/day) versus paroxetine controlled release (12.5–50 mg/day) in patients with MDD (UMIN000011191). Patients with the diagnosis of moderate-to-severe MDD (a 17-item Hamilton Rating Scale for Depression [HAMD-17], with total score at baseline being $20) were recruited to participate in a parallel, randomized, controlled trial. The primary outcome for efficacy was an improvement in the 21-item HAMD (HAMD-21) total score at 24 weeks. The secondary outcomes were the response, remission, and discontinuation rates and the incidence of individual adverse events. Results: A total of 88 patients with MDD (males, 61.4% mean age, 40.8�13.4 years) were recruited. The discontinuation rate was 58.0% (escitalopram, 55.8% paroxetine controlled release, 60.0%). Both escitalopram and paroxetine controlled-release treatment groups exhibited significant reduction in the HAMD-21 total score at 2, 4, 8, 12, and 24 weeks from the baseline. However, there were no significant differences in the HAMD-21 total score, response rate, remission rate, and discontinuation rate at any time point between the groups. In addition, there were no significant differences in the incidence of any individual adverse events (eg, nausea, vomiting, and somnolence) between the treatment groups. Conclusion: Our results suggest that escitalopram and paroxetine controlled release had similar efficacy and safety profiles in patients with MDD. One of the primary limitations of this study is the small sample size.
  • 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 91-97 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. (C) 2015 Elsevier Inc. All rights reserved.
  • Branko Aleksic, Itaru Kushima, Ryota Hashimoto, Kazutaka Ohi, Masashi Ikeda, Akira Yoshimi, Yukako Nakamura, Yoshihito Ito, Tomo Okochi, Yasuhisa Fukuo, Yuka Yasuda, Motoyuki Fukumoto, Hidenaga Yamamori, Hiroshi Ujike, Michio Suzuki, Toshiya Inada, Masatoshi Takeda, Kozo Kaibuchi, Nakao Iwata, Norio Ozaki
    Schizophrenia bulletin 39(3) 720-8 2013年5月  査読有り
    In recently completed Japanese genome-wide association studies (GWAS) of schizophrenia (JPN_GWAS) one of the top association signals was detected in the region of VAV3, a gene that maps to the chromosome 1p13.3. In order to complement JPN_GWAS findings, we tested the association of rs1410403 with brain structure in healthy individuals and schizophrenic patients and performed exon resequencing of VAV3. We performed voxel-based morphometry (VBM) and mutation screening of VAV3. Four independent samples were used in the present study: (1) for VBM analysis, we used case-control sample comprising 100 patients with schizophrenia and 264 healthy controls, (2) mutation analysis was performed on a total of 321 patients suffering from schizophrenia, and 2 case-control samples (3) 729 unrelated patients with schizophrenia and 564 healthy comparison subjects, and (4) sample comprising 1511 cases and 1517 healthy comparison subjects and were used for genetic association analysis of novel coding variants with schizophrenia. The VBM analysis suggests that rs1410403 might affect the volume of the left superior and middle temporal gyri (P=.011 and P=.013, respectively), which were reduced in patients with schizophrenia compared with healthy subjects. Moreover, 4 rare novel missense variants were detected. The mutations were followed-up in large independent sample, and one of the novel variants (Glu741Gly) was associated with schizophrenia (P=.02). These findings demonstrate that VAV3 can be seen as novel candidate gene for schizophrenia in which both rare and common variants may be related to increased genetic risk for schizophrenia in Japanese population.
  • Taro Kishi, Yasuhisa Fukuo, Tomo Okochi, Kunihiro Kawashima, Masatsugu Moriwaki, Osamu Furukawa, Giovanna M. Musso, Kiyoshi Fujita, Christoph U. Correll, Nakao Iwata
    HUMAN PSYCHOPHARMACOLOGY-CLINICAL AND EXPERIMENTAL 28(3) 220-229 2013年5月  査読有り
    Objectives We investigated whether nicotine dependence affects these endophenotypes in Japanese schizophrenia patients and whether alpha4 and beta2 subunits of neuronal nicotinic acetylcholine receptor genes (alpha4 subunit of the nAChR gene (CHRNA4)/beta2 subunit of the nAChR gene (CHRNB2)) were associated with nicotine dependence in patients (n=100) and healthy controls (n=107). Methods First, in patients, we evaluated cognitive function, using the Brief Assessment of Cognition in Schizophrenia, and acoustic startle responses. Second, we evaluated the severity of nicotine dependence, using the Tobacco Dependence Screener, the Fagerstrom Test for Nicotine Dependence, and the Brinkman index in current smokers in both groups. Third, we evaluated the relationship between acoustic startle responses, cognitive function, and severity of nicotine dependence. Finally, using 12 tagging single-nucleotide polymorphisms in each the CHRNA4/CHRNB2, we used multiple linear regression analysis to examine the association between nicotine dependence measures and each selected single-nucleotide polymorphism. Results The presence and severity of nicotine dependence were associated with verbal memory and executive function in schizophrenia patients. However, nicotine dependence was not correlated with any acoustic startle response. In addition, rs755203 and rs1044397 in CHRNA4 were associated with nicotine dependence in healthy controls. Conclusions Nicotine dependence might influence the level of verbal memory and executive function in schizophrenia patients. In addition, rs755203 and rs1044397 in CHRNA4 might play a role in the pathophysiology of nicotine dependence in healthy controls in the Japanese population. Copyright (c) 2013 John Wiley & Sons, Ltd.
  • Atsushi Takata, Yoshimi Iwayama, Yasuhisa Fukuo, Masashi Ikeda, Tomo Okochi, Motoko Maekawa, Tomoko Toyota, Kazuo Yamada, Eiji Hattori, Tetsuo Ohnishi, Manabu Toyoshima, Hiroshi Ujike, Toshiya Inada, Hiroshi Kunugi, Norio Ozaki, Shinichiro Nanko, Kazuhiko Nakamura, Norio Mori, Shigenobu Kanba, Nakao Iwata, Tadafumi Kato, Takeo Yoshikawa
    Biological psychiatry 73(6) 532-9 2013年3月15日  査読有り
    BACKGROUND: Genome-wide association studies have successfully identified several common variants showing robust association with schizophrenia. However, individually, these variants only produce a weak effect. To identify genetic variants with larger effect sizes, increasing attention is now being paid to uncommon and rare variants. METHODS: From the 1000 Genomes Project data, we selected 47 candidate single nucleotide variants (SNVs), which were: 1) uncommon (minor allele frequency < 5%); 2) Asian-specific; 3) missense, nonsense, or splice site variants predicted to be damaging; and 4) located in candidate genes for schizophrenia and bipolar disorder. We examined their association with schizophrenia, using a Japanese case-control cohort (2012 cases and 2781 control subjects). Additional meta-analysis was performed using genotyping data from independent Han-Chinese case-control (333 cases and 369 control subjects) and family samples (9 trios and 284 quads). RESULTS: We identified disease association of a missense variant in GRIN3A (p.R480G, rs149729514, p = .00042, odds ratio [OR] = 1.58), encoding a subunit of the N-methyl-D-aspartate type glutamate receptor, with study-wide significance (threshold p = .0012). This association was supported by meta-analysis (combined p = 3.3 × 10(-5), OR = 1.61). Nominally significant association was observed in missense variants from FAAH, DNMT1, MYO18B, and CFB, with ORs of risk alleles ranging from 1.41 to 2.35. CONCLUSIONS: The identified SNVs, particularly the GRIN3A R480G variant, are good candidates for further replication studies and functional evaluation. The results of this study indicate that association analyses focusing on uncommon and rare SNVs are a promising way to discover risk variants with larger effects.
  • Taro Kishi, Reiji Yoshimura, Yasuhisa Fukuo, Tomo Okochi, Shinji Matsunaga, Wakako Umene-Nakano, Jun Nakamura, Alessandro Serretti, Christoph U. Correll, John M. Kane, Nakao Iwata
    EUROPEAN ARCHIVES OF PSYCHIATRY AND CLINICAL NEUROSCIENCE 263(2) 105-118 2013年3月  査読有り
    The serotonin 1A receptor gene (HTR1A) has been associated with mood disorders (MDs), including major depressive disorder (MDD) and bipolar disorder (BP). Therefore, we conducted a systematic review and meta-analysis between rs6295 (C-1019G) as well as rs878567 in HTR1A and MDs. Searching PubMed through May 2012, 15 studies, including our own, previously unpublished association study (135 MDD patients and 107 healthy controls), met inclusion criteria for the meta-analysis of rs6295 (4,297 MDs patients and 5,435 controls). Five association studies met criteria for the meta-analysis of rs878567 (2041MDs patients and 2,734 controls). rs6295 was associated with combined MDs (P (allele model) = 0.007 and P (recessive model) = 0.01). When divided by diagnostic subgroup (MDD = 3,119 patients and 4,380 controls or BP = 1,170 patients and 2,252 controls), rs6295 was associated with each MDs separately (MDD: P (allele model) = 0.006, P (recessive model) = 0.01; BP: P (dominant model) = 0.003). Likewise, rs878567 was associated with combined MDs (2,041 patients and 2,734 controls (P (allele model) = 0.0002, P (dominant model) = 0.0008, and P (recessive model) = 0.01). When divided by diagnostic subgroup (MDD = 1,013 patients and 1,728 controls or BP = 1,051 patients and 2,099 controls), rs878567 was associated with MDD (P (allele model) = 0.0007 and P (dominant model) = 0.01), while only one BP study had such data, precluding a meta-analysis. All of these significances survived correction for multiple comparisons. Results from this expanded meta-analysis, which included our own new study, suggest that rs6295 (C-1019G) and rs878567 in HTR1A are related to the pathophysiology of MDs, with overlap between MDD and BP. Findings provide additional clues to the underlying biology and treatment targets in MDs.
  • Shinji Matsunaga, Masashi Ikeda, Taro Kishi, Yasuhisa Fukuo, Branko Aleksic, Reiji Yoshimura, Tomo Okochi, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Wakako Umene-Nakano, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Hiroshi Ujike, Jun Nakamura, Norio Ozaki, Tsuyoshi Kitajima, Nakao Iwata
    NEUROSCIENCE LETTERS 529(1) 66-69 2012年10月  査読有り
    Disturbances of the circadian rhythm are involved in the pathophysiology of bipolar disorder (BD), schizophrenia (SCZ) and major depressive disorder (MDD). Specifically, because clock gene dysfunction is good candidate for enhancing the susceptibility to these psychiatric disorders, we selected two circadian rhythm-related genes (CSNK1D and CSNK1E) and investigated genetic associations of the genes with these three disorders. None of the SNPs showed a significant association with MDD, but a SNP (rs2075984) in CSNK1E and SNP (rs6502097) in CSNK1D were associated with SCZ (P=0.0091. uncorrected) and BD (P=0.030, uncorrected), respectively. To confirm these findings, we analyzed an independent dataset (maximum N=3815) but found a lack of association (P=0.63 for rs2075984 and P=0.61 for rs6502097). The final meta-analysis showed no association between these SNPs with SCZ (P=0.21) and BD (P=0.53). These results do not support that genetic variation in CSNK1D and CSNK1E is a susceptibility factor for major psychiatric disorders in the Japanese population. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
  • Taro Kishi, Yasuhisa Fukuo, Tomo Okochi, Kunihiro Kawashima, Masatsugu Moriwaki, Osamu Furukawa, Kiyoshi Fujita, Giovanna M. Musso, Christoph U. Correll, John M. Kane, Nakao Iwata
    NEUROMOLECULAR MEDICINE 14(2) 131-138 2012年6月  査読有り
    Recently, schizophrenia endophenotypes have been actively investigated to better understand the pathophysiology of schizophrenia. Past studies have shown that cognitive functions, including working memory and executive function, correlate with acoustic startle responses, such as prepulse inhibition (PPI), in patients with schizophrenia. The aim of this study was to investigate the relationship between cognitive functions and acoustic startle response in Japanese patients with schizophrenia. In 100 patients with schizophrenia, we evaluated cognitive function, using the Brief Assessment of Cognition in Schizophrenia, Japanese-language version (BACS-J), and acoustic startle responses, including acoustic startle reflex, habituation, and PPI (three different intensities: 82, 86, and 90 dB SPL, equivalent to signal-to-noise ratios of +12, +16, and +20 dB, respectively). Using multiple regression analysis, we examined the relationship between acoustic startle responses and BACS-J primary measures or composite score. Level of attention was associated with magnitude of habituation in schizophrenia ( = 0.0009, beta = -0.357). None of the other domains of cognitive function were significantly associated with any measure of acoustic startle response. This included attention regarding ASR ( = 0.513), PPI ( = 0.521-0.842), verbal memory ( = 0.423-0.981), working memory ( = 0.312-0.966), motor speed ( = 0.323-0.955), verbal fluency ( = 0.125-0.920), executive function ( = 0.118-0.470), and the BACS-J composite score ( = 0.230-0.912). In this first investigation of the relationship between cognitive functions and acoustic startle responses in Japanese patients with schizophrenia, attentional deficits correlated highly with the level of habituation. However, a replication study using other population samples is required to further investigate this relationship.
  • Maiko Kitazawa, Tohru Ohnuma, Yuto Takebayashi, Nobuto Shibata, Hajime Baba, Kazutaka Ohi, Yuka Yasuda, Yukako Nakamura, Branko Aleksic, Akira Yoshimi, Tomo Okochi, Masashi Ikeda, Hiroshi Naitoh, Ryota Hashimoto, Nakao Iwata, Norio Ozaki, Masatoshi Takeda, Heii Arai
    AMERICAN JOURNAL OF MEDICAL GENETICS PART B-NEUROPSYCHIATRIC GENETICS 159B(4) 456-464 2012年6月  査読有り
    Recent GWAS demonstrated an association between candidate genes located at region 6p22.1 and schizophrenia. This region has been reported to house certain candidate SNPs, which may be associated with schizophrenia at HIST1H2BJ, PRSS16, and PGBD1. These genes may presumably be associated with pathophysiology in schizophrenia, namely epigenetics and psychoneuroimmunology. A three-step study was undertaken to focus on these genes with the following aims: (1) whether these genes may be associated in Japanese patients with schizophrenia by performing a 1st stage casecontrol study (514 cases and 706 controls) using Japanese tagging SNPs; (2) if the genetic regions of interest for the disease from the 1st stage of analyses were found, re-sequencing was performed to search for new mutations; (3) finally, a replication study was undertaken to confirm positive findings from the 1st stage were reconfirmed using a larger number of subjects (2,583 cases and 2,903 controls) during a 2nd stage multicenter replication study in Japan. Genotyping was performed using TaqMan PCR method for the selected nine tagging SNPs. Although three SNPs situated at the 3' side of PGBD1; rs3800324, rs3800327, and rs2142730, and two-window haplotypes between rs3800327 and rs2142730 showed positive associations with schizophrenia, these associations did not have enough power to sustain significance during the 2nd stage replication study. In addition, re-sequencing for exons 5 and 6 situated at this region did not express any new mutations for schizophrenia. Taken together these results indicate that the genes HIST1H2BJ, PRSS16, and PGBD1 were not associated with Japanese patients with schizophrenia. (C) 2012 Wiley Periodicals, Inc.
  • Itaru Kushima, Yukako Nakamura, Branko Aleksic, Masashi Ikeda, Yoshihito Ito, Tomoko Shiino, Tomo Okochi, Yasuhisa Fukuo, Hiroshi Ujike, Michio Suzuki, Toshiya Inada, Ryota Hashimoto, Masatoshi Takeda, Kozo Kaibuchi, Nakao Iwata, Norio Ozaki
    SCHIZOPHRENIA BULLETIN 38(3) 552-560 2012年5月  査読有り
    Our genome-wide association study of schizophrenia found association signals at the Kalirin gene (KALRN) and EPH receptor B1 gene (EPHB1) in a Japanese population. The importance of these synaptogenic pathway genes in schizophrenia is gaining independent supports. Although there has been growing interest in rare (&lt; 1%) missense mutations as potential contributors to the unexplained heritability of schizophrenia, there are no population-based studies targeting rare (&lt; 1%) coding mutations with a larger effect size (eg, OR &gt; 1.5) in KALRN or EPHB1. The present study design consisted of 3 phases. At the discovery phase, we conducted resequencing analyses for all exon regions of KALRN and EPHB1 using a DNA microarray-based method. Seventeen rare (&lt; 1%) missense mutations were discovered in the first sample set (320 schizophrenic patients). After the prioritization phase based on frequencies in the second sample set (729 cases and 562 controls), we performed association analyses for each selected mutation using the third sample set (1511 cases and 1517 controls), along with a combined association analysis across all selected mutations. In KALRN, we detected a significant association between schizophrenia and P2255T (OR = 2.09, corrected P = .048, 1 tailed); this was supported in the combined association analysis (OR = 2.07, corrected P = .006, 1 tailed). We found no evidence of association of EPHB1 with schizophrenia. In silico analysis indicated the functional relevance of these rare missense mutations. We provide evidence that multiple rare (&lt; 1%) missense mutations in KALRN may be genetic risk factors for schizophrenia.
  • Kishi T, Fukuo Y, Okochi T, Kawashima K, Kitajima T, Inada T, Ozaki N, Musso GM, Kane JM, Correll CU, Iwata N
    Human psychopharmacology 27(1) 63-69 2012年1月  査読有り
  • Taro Kishi, Yasuhisa Fukuo, Tomo Okochi, Tsuyoshi Kitajima, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Christoph U. Correll, Nakao Iwata
    HUMAN PSYCHOPHARMACOLOGY-CLINICAL AND EXPERIMENTAL 26(7) 445-450 2011年10月  査読有り
    Objectives We previously showed that the sirtuin 1 gene (SIRT1 gene), one of the clock genes, was associated with schizophrenia in a Japanese patient population. Because the symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia and because not every METH user develops psychosis, it is conceivable that METH-induced psychosis and schizophrenia have common susceptibility genes. Therefore, we conducted an analysis of the association of SIRT1 gene with METH-induced psychosis, hypothesizing a significant relationship. Methods This paper presents a case-control study of the SIRT1 gene in 515 Japanese individuals (197 with METH-induced psychosis and 318 age-matched and sex-matched controls) with four tagging single nucleotide polymorphisms (rs12778366, rs2273773, rs4746720, and rs10997875), selected a priori using the HapMap database. Results rs10997875 (located in the 3&apos; flanking region) was associated with METH-induced psychosis (unadjusted p(genotype)=0.0203). However, these results became non-significant after Bonferroni correction (corrected p(genotype)=0.0812). In the all-marker haplotype analysis, the SIRT1 gene was not associated with METH-induced psychosis (p=0.146). Conclusion Our findings suggest that SIRT1 gene does not contribute to the development of METH-induced psychosis in the Japanese population. However, a replication study using larger samples should be conducted to obtain conclusive results. Copyright (C) 2011 John Wiley & Sons, Ltd.
  • Yasuhisa Fukuo, Taro Kishi, Itaru Kushima, Reiji Yoshimura, Tomo Okochi, Tsuyoshi Kitajima, Shinji Matsunaga, Kunihiro Kawashima, Wakako Umene-Nakano, Hiroshi Naitoh, Toshiya Inada, Jun Nakamura, Norio Ozaki, Nakao Iwata
    JOURNAL OF AFFECTIVE DISORDERS 133(1-2) 150-157 2011年9月  査読有り
    Background: Several investigations have reported that abnormalities in circadian rhythms might be related to the pathophysiology of major depressive disorder (MDD) and the therapeutic response to selective serotonin reuptake inhibitors (SSRIs). Recently, ubiquitin-specific peptidase 46 (USP46), a new molecule related to the circadian clock system, has been described. We conducted a case control study between seven tagging SNPs (rs10517263, rs17675844, rs6554557, rs12646800, rs2244291, rs10034164, rs346005) in the USP46 gene, MDD, and the SSRI therapeutic response in MDD in the Japanese population. Method: We recruited 432 MOD patients (202 males and 230 females) and 792 healthy controls (319 males and 473 females). Two hundred sixty-one of 432 MOD patients were treated with SSRIs (fluvoxamine, sertraline or paroxetine). Result: We detected an association between the USP46 gene and MOD in a haplotype analysis (rs2244291-rs10034164-rs346005 and rs12646800-rs2244291-rs10034164-rs346005). However, we did not find any association between the USP46 gene and SSRI response or remission in MDD in the Japanese population. Limitations: A replication study using larger samples may be required for conclusive results, since our sample size was small. Conclusions: Our results suggest that the USP46 gene might play a role in the pathophysiology of MOD in the Japanese population. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
  • Taro Kishi, Tomo Okochi, Tsuyoshi Kitajima, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Christoph U. Correll, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 35(7) 1618-1622 2011年8月  査読有り
    Objectives: Recently, we detected that the prokineticin 2 receptor gene was associated with not only major depressive disorder (MDD) but also methamphetamine dependence. Therefore, it is possible that mood disorders and drug addiction have shared susceptibility genes. The translin-associated factor X gene (TSNAX)/disrupted-in-schizophrenia-1 gene (DISC1) has been associated with psychiatric disorders, including schizophrenia, MDD and bipolar disorder. TSNAX is located immediately upstream of DISC1 and has been shown to undergo intergenic splicing with DISC1. Based on this evidence, we hypothesized that TSNAX might be a good candidate gene for methamphetamine dependence. Methods: We conducted a case-control study of Japanese individuals (215 with methamphetamine dependence and 318 age- and sex-matched controls) with three tagging SNPs (rs1630250, rs766288 and rs6662926) selected by HapMap database. Results: rs1630250 was associated in males with methamphetamine dependence in the allele analysis (P-value: 0.0253). However, these results did not remain significant after Bonferroni correction to adjust for multiple comparisons (corrected P-value: 0.152). Conclusion: Our findings suggest that TSNAX does not play a role in methamphetamine dependence in the Japanese population. A replication study using larger samples needs to be conducted to obtain conclusive results. (C) 2011 Elsevier Inc. All rights reserved.
  • Masashi Ikeda, Branko Aleksic, Yoko Kinoshita, Tomo Okochi, Kunihiro Kawashima, Itaru Kushima, Yoshihito Ito, Yukako Nakamura, Taro Kishi, Takenori Okumura, Yasuhisa Fukuo, Hywel J. Williams, Marian L. Hamshere, Dobril Ivanov, Toshiya Inada, Michio Suzuki, Ryota Hashimoto, Hiroshi Ujike, Masatoshi Takeda, Nick Craddock, Kozo Kaibuchi, Michael J. Owen, Norio Ozaki, Michael C. O&apos;Donovan, Nakao Iwata
    BIOLOGICAL PSYCHIATRY 69(5) 472-478 2011年3月  査読有り
    Background: Genome-wide association studies have detected a small number of weak but strongly supported schizophrenia risk alleles. Moreover, a substantial polygenic component to the disorder consisting of a large number of such alleles has been reported by the International Schizophrenia Consortium. Method: We report a Japanese genome-wide association study of schizophrenia comprising 575 cases and 564 controls. We attempted to replicate 97 markers, representing a nonredundant panel of markers derived mainly from the top 150 findings, in up to three data sets totaling 1990 cases and 5389 controls. We then attempted to replicate the observation of a polygenic component to the disorder in the Japanese and to determine whether this overlaps that seen in UK populations. Results: Single-locus analysis did not reveal genome-wide support for any locus in the genome-wide association study sample (best p = 6.2 x 10(-6)) or in the complete data set in which the best supported locus was SULT6B1 (rs11895771: p = 3.7 x 10(-5) in the meta-analysis). Of loci previously supported by genome-wide association studies, we obtained in the Japanese support for NOTCH4 (rs2071287: p(meta) = 5.1 x 10(-5)). Using the approach reported by the International Schizophrenia Consortium, we replicated the observation of a polygenic component to schizophrenia within the Japanese population (p = .005). Our trans Japan-UK analysis of schizophrenia also revealed a significant correlation (best p = 7.0 x 10(-5)) in the polygenic component across populations. Conclusions: These results indicate a shared polygenic risk of schizophrenia between Japanese and Caucasian samples, although we did not detect unequivocal evidence for a novel susceptibility gene for schizophrenia.
  • Taro Kishi, Tsuyoshi Kitajima, Kunihiro Kawashima, Tomo Okochi, Yoshio Yamanouchi, Yoko Kinoshita, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    CURRENT NEUROPHARMACOLOGY 9(1) 129-132 2011年3月  査読有り
    Several investigations suggested abnormalities in circadian rhythms are related to the pathophysiology of psychiatric disorders, including drug addiction. Recently, orphan nuclear receptor rev-erb alpha and glycogen synthase kinase-3 beta (GSK-3 beta) were shown to be important circadian components. In addition, the orphan nuclear receptor rev-erb alpha is a key negative feedback regulator of the circadian clock. These evidences indicate that rev-erb alpha gene (NR1D1) is a good candidate gene for the pathogenesis of methamphetamine dependence. To evaluate the association between NR1D1 and methamphetamine dependence, we conducted a case-control study of Japanese samples (215 methamphetamine dependence and 232 controls) with three tagging SNPs selected by HapMap database. Written informed consent was obtained from each subject. This study was approved by the ethics committees at Fujita Health University, Nagoya University Graduate School of Medicine and each participating member of the Institute of the Japanese Genetics Initiative for Drug Abuse (JGIDA). We did not detect an association between NR1D1 and Japanese methamphetamine dependence patients in allele/genotype-wise analysis, or the haplotype analysis. Our findings suggest that NR1D1 does not play a major role in the pathophysiology of methamphetamine dependence in the Japanese population.
  • Taro Kishi, Tsuyoshi Kitajima, Tomoko Tsunoka, Takenori Okumura, Kunihiro Kawashima, Tomo Okochi, Yoshio Yamanouchi, Yoko Kinoshita, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    CURRENT NEUROPHARMACOLOGY 9(1) 133-136 2011年3月  査読有り
    Disruption of circadian rhythms may be involved in the pathophysiology of psychiatric disorders, including drug addiction. Recently, we detected the significant association between prokineticin 2 receptor gene (PROKR2) and Japanese methamphetamine dependence patients. Also, prokineticin 2 (PK2) gene deficient mice showed reduced physiological and behavioral parameters, including circadian locomotor activity, circulating glucocorticoid, glucose levels and the expression of peripheral clock genes compared with WT mice. These evidences indicate that PK2 gene (PROK2) is a good candidate gene for the pathogenesis of methamphetamine dependence. To evaluate the association between PROK2 and methamphetamine dependence, we conducted a case-control study of Japanese samples (215 methamphetamine dependence and 232 controls) with four tagging SNPs selected by HapMap database. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients. Written informed consent was obtained from each subject. This study was approved by the ethics committees at Fujita Health University, Nagoya University Graduate School of Medicine and each participating member of the Institute of the Japanese Genetics Initiative for Drug Abuse (JGIDA). We did not detect an association between PROK2 and Japanese methamphetamine dependence patients in allele/genotype-wise analysis, or the haplotype analysis. Our findings suggest that PROK2 does not play a major role in the pathophysiology of methamphetamine dependence in the Japanese population.
  • Takenori Okumura, Tomo Okochi, Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoko Kinoshita, Kunihiro Kawashima, Tomoko Tsunoka, Yasuhisa Fukuo, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Masaomi Iyo, Ichiro Sora, Norio Ozaki, Hiroshi Ujike, Nakao Iwata
    CURRENT NEUROPHARMACOLOGY 9(1) 155-159 2011年3月  査読有り
    The neuronal nitric oxide synthase gene (NOS1) is located at 12q24, a susceptibility region for schizophrenia, and produces nitric oxide (NO). NO has been reported to play important roles as a gaseous neurotransmitter in brain. NO is a second messenger for the N-methyl-D aspartate (NMDA) receptor and is related to the dopaminergic system. Because the symptomatology of methamphetamine (METH) use disorder patients with psychosis is similar to that of patients with schizophrenia, NOS1 is a good candidate gene for METH-induced psychosis. Therefore, we conducted a case-control association study between NOS1 and METH-induced psychosis with Japanese subjects (183 with METH-induced psychosis patients and 519 controls). We selected seven SNPs (rs41279104, rs3782221, rs3782219, rs561712, rs3782206, rs6490121, rs2682826) in NOS1 from previous reports. Written informed consent was obtained from each subject. This study was approved by the Ethics Committee at Fujita Health University School of Medicine and each participating institute of the Japanese Genetics Initiative for Drug Abuse (JGIDA). No significant association was found between NOS1 and METH-induced psychosis in the allele/genotype-wise or haplotype-wise analyses. In conclusion, we suggest that NOS1 might not contribute to the risk of METH-induced psychosis in the Japanese population.
  • Tomoko Tsunoka, Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Toshiya Inada, Hiroshi Ujike, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    CURRENT NEUROPHARMACOLOGY 9(1) 160-162 2011年3月  査読有り
    Several investigations have suggested that abnormalities in glutamate neural transmission play a role in the pathophysiology of psychiatric disorders, including schizophrenia. The metabotropic glutamate 3 receptor (mGluR3) gene was reported to be associated with schizophrenia, and paranoid type schizophrenia has symptoms that are similar to those of methamphetamine-induced psychosis. This suggests that mGluR3 gene (GRM3) is a good candidate gene for the pathogenesis of methamphetamine-induced psychosis. To evaluate the association between GRM3 and methamphetamine-induced psychosis, we conducted a case-control study of Japanese samples (181 methamphetamine-induced psychosis and 232 controls). Methods: We selected one functional SNP (rs6465084), reported to be associated with prefrontal brain functioning, for an association analysis. Written informed consent was obtained from each subject. This study was approved by the ethics committees at Fujita Health University, Nagoya University Graduate School of Medicine and each participating member of the Institute of the Japanese Genetics Initiative for Drug Abuse (JGIDA). Results: We did not detect an association between rs6465084 in GRM3 and Japanese methamphetamine-induced psychosis. Conclusion: Our findings suggest that rs6465084 in GRM3 does not play a major role in the pathophysiology of methamphetamine-induced psychosis in the Japanese population. However, because we did not perform an association analysis based on linkage disequilibrium (LD) or a mutation scan of GRM3, a replication study using a larger sample and based on LD may be required for conclusive results.
  • Taro Kishi, Tomo Okochi, Tomoko Tsunoka, Takenori Okumura, Tsuyoshi Kitajima, Kunihiro Kawashima, Yoshio Yamanouchi, Yoko Kinoshita, Hiroshi Naitoh, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Hiroshi Ujike, Norio Ozaki, Nakao Iwata
    PSYCHIATRY RESEARCH 185(1-2) 20-26 2011年1月  査読有り
    Several investigations have reported associations between serotonin 1A (5-HT1A) receptor and major psychiatric disorders, such as schizophrenia and bipolar disorder (BP), making the 5-HT1A receptor gene (HTR1A) a good candidate gene for the pathophysiology of schizophrenia and BP. To evaluate the association between HTR1A and schizophrenia and BP, we conducted a case-control study of Japanese population samples with two single- nucleotide polymorphisms (SNPs), including rs6295 (C-1019G) in HTR1A. In addition, we conducted a meta-analysis of rs6295, which has been examined in other studies. Using one functional single- nucleotide polymorphism (SNP; rs6295) and one tagging SNP (rs878567), we conducted a genetic association analysis of case-control samples (857 schizophrenic patients, 1028 BP patients and 1810 controls) in the Japanese population. Two association studies for schizophrenia and three association studies for BP, including this study, met our criteria for the meta-analysis of rs6295. We found an association between HTR1A and Japanese BP in a haplotype-wise analysis, the significance of which remained after Bonferroni correction. In addition, we detected an association between rs6295 and BP in the meta-analysis (fixed model: P(Z) = 0.000400). However, we did not detect an association between HTR1A and schizophrenia in the allele/genotype-wise, haplotype-wise or meta-analysis. HTR1A may play an important role in the pathophysiology of BP, but not schizophrenia in the Japanese population. In the meta-analysis, rs6295 in HTR1A was associated with BP patients. Crown Copyright (C) 2010 Published by Elsevier Ireland Ltd. All rights reserved.
  • Taro Kishi, Yasuhisa Fukuo, Tomo Okochi, Tsuyoshi Kitajima, Kunihiro Kawashima, Hiroshi Naitoh, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    DRUG AND ALCOHOL DEPENDENCE 113(1) 1-7 2011年1月  査読有り
    Background: Altered serotonergic neural transmission is hypothesized to be a susceptibility factor for psychotic disorders such as schizophrenia. The serotonin 6 (5-HT6) receptor is therapeutically targeted by several second generation antipsychotics, such as clozapine and olanzapine, and D-amphetamine-induced hyperactivity in rats is corrected with the use of a selective 5-HT6 receptor antagonist. In addition, the disrupted prepulse inhibition induced by D-amphetamine or phencyclidine was restored by 5-HT6 receptor antagonist in an animal study using rats. These animal models were considered to reflect the positive symptoms of schizophrenia, and the above evidence suggests that altered 5-HT6 receptors are involved in the pathophysiology of psychotic disorders. The symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an analysis of the association of the 5-HT6 gene (HTR6) with METH-induced psychosis. Method: Using five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997), we conducted a genetic association analysis of case-control samples (197 METH-induced psychosis patients and 337 controls) in the Japanese population. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients. Results: rs6693503 was associated with METH-induced psychosis patients in the allele/genotype-wise analysis. Moreover, this association remained significant after Bonferroni correction. In the haplotype-wise analysis, we detected an association between two markers (rs6693503 and rs1805054) and three markers (rs6693503, rs1805054 and rs4912138) in HTR6 and METH-induced psychosis patients, respectively. Conclusion: HTR6 may play an important role in the pathophysiology of METH-induced psychosis in the Japanese population. Crown Copyright (C) 2010 Published by Elsevier Ireland Ltd. All rights reserved.
  • Taro Kishi, Reiji Yoshimura, Yasuhisa Fukuo, Tsuyoshi Kitajima, Tomo Okochi, Shinji Matsunaga, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Hiroshi Ujike, Wakako Umene-Nakano, Jun Nakamura, Norio Ozaki, Alessandro Serretti, Christoph U. Correll, Nakao Iwata
    CHRONOBIOLOGY INTERNATIONAL 28(9) 825-833 2011年  査読有り
    The clock gene (CLOCK) is considered to be a good candidate gene for the pathophysiology of mood disorders, including bipolar disorder (BP) and major depressive disorder (MDD). rs1801260 (T3111C) has been detected at position 3111 in the CLOCK mRNA 3&apos; untranslated region, and was reported to be associated with a substantial delay in preferred timing for activity and sleep in a human study. As for function, rs1801260 has been speculated to affect mRNA. Therefore, the authors investigated the association between the three tagging single-nucleotide polymorphisms (SNPs) (rs3736544, rs1801260, and rs3749474) in CLOCK and risk of BP (n = 867) and MDD (n = 139) compared to controls (n = 889) in the Japanese population. In addition, we also performed an updated meta-analysis of nine published, genetic association studies investigating the relationship between rs1801260 and mood disorder risk, comprising 3321 mood disorders cases and 3574 controls. We did not detect any associations between tagging SNPs in CLOCK and BP or MDD in the allele, genotype, or haplotype analysis (global p(BP) = .605 and global p(MDD) = .211). Moreover, rs1801260 was also not associated with BP, MDD, or any mood disorders in the meta-analysis. In conclusion, these data suggest that CLOCK does not play a major role in the pathophysiology of mood disorders. (Author correspondence: tarok@fujita-hu.ac.jp)
  • Taro Kishi, Reiji Yoshimura, Tsuyoshi Kitajima, Tomo Okochi, Takenori Okumura, Tomoko Tsunoka, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Yasuhisa Fukuo, Hiroshi Naitoh, Wakako Umene-Nakano, Toshiya Inada, Jun Nakamura, Norio Ozaki, Nakao Iwata
    JOURNAL OF AFFECTIVE DISORDERS 126(1-2) 167-173 2010年10月  査読有り
    Background: Many studies including our previous ones as to PROKR2 and CLOCK have suggested that circadian genes may be involved in the mechanisms of mood disorders and their treatment responses. Also several recent investigations have reported that SIRT1 plays an important role in the circadian system as conventional circadian clock genes, and also have some relation to dopaminergic metabolism. So we considered the SIRT1 gene to be a good candidate gene for the pathophysiology for MDD and SSRI responses in MDD, and conducted a case-control study using four tagging SNPs (450 MDD patients, including 261 patients treated by SSRIs and 766 controls). Method: The MOD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. Marker-trait association analysis was used to evaluate allele and genotype association with the chi-square test, and haplotype association analysis was evaluated with a likelihood ratio test. Result: We found an association between rs10997875 in SIRT1 gene and MDD in the allele/genotype analysis. In addition, this significance of these associations survived Bonferroni correction. However, we did not find any association between SIRT1 gene and SSRI therapeutic response in MDD in the allele/genotype analysis or haplotype analysis. Limitations: A replication study using larger samples may be required for conclusive results, since our sample size was small. Conclusions: Our results suggest that rs10997875 in SIRT1 gene may play a role in the pathophysiology of MDD in the Japanese population. (C) 2010 Elsevier B.V. All rights reserved.
  • Taro Kishi, Reiji Yoshimura, Tsuyoshi Kitajima, Tomo Okochi, Takenori Okumura, Tomoko Tsunoka, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Hiroshi Naitoh, Jun Nakamura, Norio Ozaki, Nakao Iwata
    NEUROMOLECULAR MEDICINE 12(3) 237-242 2010年9月  査読有り
    Several recent investigations reported that the serotonin 2A receptor gene (HTR2A) was associated with selective serotonin reuptake inhibitors (SSRIs) in major depressive disorder. There have also been two reported association analyses of HTR2A with SSRI response in Japanese MDD patients, but the results were rather inconsistent and both studies had the problem of small sample sizes. Therefore, we conducted a replication association study using a sample larger than those in the two original Japanese studies (265 MDD patients), and found that four SNPs, two functional SNPs (-A1438G: rs6311 and T102C: rs6313) and two SNPs (rs7997012 and rs1928040) in HTR2A, were associated with the therapeutic response to SSRIs. HTR2A was associated with the therapeutic response SSRIs in Japanese MDD patients in a haplotype-wise analysis (P (all markers) = 0.0136), and a significant association between rs1928040 in HTR2A and SSRI response was detected in MDD (P (allele-wise analysis) = 0.0252). However, this significance disappeared after Bonferroni correction (P (allele-wise analysis) = 0.101). In conclusion, we suggest that HTR2A may play an important role in the pathophysiology of the therapeutic response to SSRIs in Japanese MDD patients. However, it will be important to replicate and confirm these findings in other independent studies using large samples.
  • Yasuhisa Fukuo, Taro Kishi, Tomo Okochi, Tsuyoshi Kitajima, Tomoko Tsunoka, Takenori Okumukura, Yoko Kinoshita, Kunihiro Kawashima, Yoshio Yamanouchi, Wakako Umene-Nakano, Hiroshi Naitoh, Toshiya Inada, Reiji Yoshimura, Jun Nakamura, Norio Ozaki, Nakao Iwata
    NEUROMOLECULAR MEDICINE 12(3) 285-291 2010年9月  査読有り
    Several investigations have reported that abnormalities in circadian rhythms might be related with the pathophysiology of psychiatric disorders, since many psychiatric patients have insomnia and sleep-awake disturbance. A recent animal study reported that Magel2, which encodes a member of the MAGE/necdin family of proteins, might be associated in the pathophysiology of psychiatric disorders. Magel2 gene knockout mice showed altered concentrations of both dopamine and serotonin in several parts of the brain compared with controls. In addition, the authors of that study detected a bilateral reduction in cortical volume in distinct regions of the Magel2 gene knockout mice brain, including focused regions in the parieto-temporal lobe of the cerebral cortex, the amygdala, the hippocampus, and the nucleus accumbens. These mice were also found to have hypoactivity and abnormalities in circadian rhythms. From this evidence, we considered Magel2 gene (MAGEL2) to be a good candidate gene for the pathophysiology of schizophrenia and mood disorder, and we conducted a case-control study among Japanese (731 schizophrenia patients, 465 MDD patients, 156 BP patients and 758 controls) using three tagging SNPs in MAGEL2 (rs850815, rs8920 and rs4480754), selected using the HapMap database. We did not find any association between MAGEL2 and schizophrenia, BP or MDD in allele/genotype-wise analysis or haplotype-wise analysis. Our results suggest that MAGEL2 may not play a role in the pathophysiology of schizophrenia and mood disorders in the Japanese population. A replication study using larger samples may be required for conclusive results, since our sample size was small and our study analyzed only three SNPs in MAGEL2.
  • Taro Kishi, Tsuyoshi Kitajima, Tomoko Tsunoka, Takenori Okumura, Tomo Okochi, Kunihiro Kawashima, Toshiya Inada, Hiroshi Ujike, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 34(6) 1033-1036 2010年8月  査読有り
    Background: Many patients with drug addiction are reported to have comorbid mood disorders. One of the suggested pathophysiological mechanisms for mood disorders is disruption of circadian rhythms. Several animal studies have shown that methamphetamine altered the expression of circadian clock molecules in the brain. Therefore, it is possible that mood disorders and drug addiction have common susceptibility genes. Recently, we reported that the prokineticin 2 receptor gene (PROKR2) was associated with mood disorders including major depressive disorder and bipolar disorder in the Japanese population. In the present study, therefore, we conducted an association analysis of tagging SNPs in PROKR2 with Japanese methamphetamine dependence patients. Methods: Using five tagging SNPs in PROKR2, we conducted a genetic association analysis of case control samples (199 methamphetamine dependence patients and 337 healthy controls). The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients. Results: We detected a significant association between PROKR2 and methamphetamine dependence patients in allele/genotype-wise and haplotype-wise analysis. Conclusion: Our results suggest that PROKR2 may play a role in the pathophysiology of methamphetamine dependence in the Japanese population. However, because we did not perform a mutation scan of PROKR2, a replication study using a larger sample may be required for conclusive results. (C) 2010 Elsevier Inc. All rights reserved.
  • Taro Kishi, Yasuhisa Fukuo, Reiji Yoshimura, Tomo Okochi, Tsuyoshi Kitajima, Hiroshi Naitoh, Wakako Umene-Nakano, Jun Nakamura, Norio Ozaki, Nakao Iwata
    HUMAN PSYCHOPHARMACOLOGY-CLINICAL AND EXPERIMENTAL 25(6) 481-486 2010年8月  査読有り
    Objective Several investigations have suggested that alterations in serotonin 6 (5-HT6) receptors might be associated with the pathophysiology of major depressive disorder (MDD), and that 5-HT6 receptors might be a therapeutic target for serotonin selective reuptake inhibitor (SSRI) in MDD. To evaluate the association between HTR6 and the efficacy of SSRI treatment in Japanese MDD patients, we conducted a case-control study in a Japanese population sample. Methods We selected five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997), and performed an association analysis of HTR6 and the efficacy of SSRI treatment in 260 MDD patients. Results We did not detect an association between tagging SNPs in HTR6 and the therapeutic response to SSRI in MDD in allele/genotype or haplotype analysis. Conclusions HTR6 may not play an important role in the pathophysiology of SSRI response in the Japanese population. Because our sample was relatively small, statistical errors were possible in the results of our association analyses. To overcome these limitations, a replication study using a larger sample may be required for conclusive results. Copyright (C) 2010 John Wiley & Sons, Ltd.
  • Yasuhisa Fukuo, Taro Kishi, Reiji Yoshimura, Tsuyoshi Kitajima, Tomo Okochi, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Hiroshi Naitoh, Wakako Umene-Nakano, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Hiroshi Ujike, Jun Nakamura, Norio Ozaki, Nakao Iwata
    NEUROSCIENCE RESEARCH 67(3) 250-255 2010年7月  査読有り
    Several evidence suggests that alterations in serotonin 6 (5-HT6) receptors might be associated with the pathophysiology of mood disorders. Therefore, to evaluate the association between HTR6 and BP and MDD, we conducted a case-control study of Japanese population samples (1007 BP patients, 447 MDD patients and 1753 controls) with five tagging SNPs, including rs1805054 (C267T), in HTR6. In addition, we conducted a meta-analysis of rs1805054, which has been examined in other studies. We selected five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997). Moreover, three association studies for BP and four association studies for MDD, including this study, met our criteria for the meta-analysis of rs1805054. We did not detect an association between tagging SNPs in HTR6 and BP and MDD in the allele/genotype, haplotype analysis or meta-analysis. In conclusion, we found no association involving polymorphism and mood disorder in the Japanese population. However, because changes in expression level or signal transduction of this receptor may be involved in the pathology of these diseases, it will be necessary to conduct the further study about the relationship between this receptor and mood disorders in the future. Crown Copyright (C) 2010 Published by Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
  • Taro Kishi, Reiji Yoshimura, Tomo Okochi, Yasuhisa Fukuo, Tsuyoshi Kitajima, Takenori Okumura, Tomoko Tsunoka, Kunihiro Kawashima, Yoshio Yamanouchi, Yoko Kinoshita, Wakako Umene-Nakano, Hiroshi Naitoh, Jun Nakamura, Norio Ozaki, Nakao Iwata
    NEUROPHARMACOLOGY 58(7) 1168-1173 2010年6月  査読有り
    Background: Several investigations have suggested the possible involvement of sigma1 non-opioid intracellular receptor 1 (sigma1 receptor) in the pathophysiology of major depressive disorder (MDD). Sigma1 receptors are also one of the major pharmacological therapeutic targets of selective serotonin reuptake inhibitors (SSRIs). To evaluate the association of sigma1 receptor gene (SIGMAR1) and MDD and SSRIs therapeutic response in MDD, we conducted a case control study of Japanese samples (466 MDD patients, 516 controls and 208 MDD patients treated by fluvoxamine or sertraline). Method: We defined a clinical response as a decrease of more than 50% in baseline the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D) within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. Therefore, we selected rs1800866 in SIGMAR1 for the following association analysis. Results: In the logistic regression analysis, we detected an association of the phenotypes (MDD or controls) with rs1800866 genotype. However, we did not detect an association between rs1800866 and SSRI therapeutic response in Japanese MDD. In addition, remission with SSRI was not associated with rs1800866. Also, we did not detect a novel polymorphism in SIGMAR1 when we performed a mutation search using MDD treated by SSRIs samples. Conclusion: Our results suggest that rs1800866 in SIGMAR1 may play a role in the pathophysiology of MDD in the Japanese population. Also, SIGMAR1 does not play a role in the therapeutic response to SSRI in Japanese MDD patients. However, because our sample was small, a replication study using another population and larger sample will be required for conclusive results. (C) Crown Copyright 2010 Published by Elsevier Ltd. All rights reserved.
  • Tomoko Tsunoka, Taro Kishi, Tsuyoshi Kitajima, Tomo Okochi, Takenori Okumura, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Hiroshi Naitoh, Toshiya Inada, Hiroshi Ujike, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 34(4) 639-644 2010年5月  査読有り
    Background: Abnormalities in glutaminergic neural transmission have been suggested to be involved in the pathogenesis of schizophrenia. A recent study reported that alterations in the 5-HT2A-mGluR2 complex may be involved in neural transmission in the schizophrenic cortex. In addition, methamphetamine-induced psychosis is thought to be similar to schizophrenia. Therefore, we conducted a case-control study with Japanese samples (738 schizophrenia patients, 196 methamphetamine-induced psychosis patients, and 802 controls) to evaluate the association and interaction between GRM2, HTR2A and schizophrenia. Methods: We selected three 'tagging SNPs' in GRM2, and two biologically functional SNPs in HTR2A (T102C and A1438G), for the association analysis. Results: We detected a significant association between methamphetamine-induced psychosis and GRM2 in a haplotype-wise analysis, but not HTR2A. We did not detect an association between GRM2 or HTR2A and schizophrenia. In addition, no interactions of GRM2 and HTR2A were found in methamphetamine-induced psychosis or schizophrenia. We did not detect any novel polymorphisms in GRM2 when we performed a mutation search using methamphetamine-induced psychosis samples. Conclusion: Our results suggested that GRM2 may play a role in the pathophysiology of methamphetamine-induced psychosis but not schizophrenia in the Japanese population. A replication study using larger samples or samples of other populations will be required for conclusive results. Crown Copyright (C) 2010 Published by Elsevier Inc. All rights reserved.
  • Taro Kishi, Masatsugu Moriwaki, Kunihiro Kawashima, Tomo Okochi, Yasuhisa Fukuo, Tsuyoshi Kitajima, Osamu Furukawa, Hiroshi Naitoh, Kiyoshi Fujita, Nakao Iwata
    NEUROSCIENCE RESEARCH 66(4) 340-344 2010年4月  査読有り
    Several investigators have reported cognitive dysfunction in chronic schizophrenia that was associated with insight and social skills. Such cognitive dysfunction seriously hinders an immediate return to normal life. Recently. Kaneda et al. reported that the Brief Assessment of Cognition in Schizophrenia. Japanese-language version (BACS-J) was superior in the evaluation of the cognitive function. We investigated which clinical factors (age, sex, duration of illness, level of education, smoking status, the Positive and Negative Syndrome Scale (PANSS) score and medication dosage) affected cognitive dysfunction in 115 Japanese schizophrenic patients, with the use of multiple regression analysis. We detected an association between composite score, verbal memory, working memory and executive function and PANSS total score. Moreover, most cognitive tasks were associated with a negative PANSS score but not a positive PANSS score or general score. We also showed an association between age and verbal fluency and attention in schizophrenia. In addition, anxiolytics/hypnotics (diazepam-equivalent) were associated with composite score, working memory and motor speed. In conclusion, cognitive function was associated with PANSS score, especially negative PANSS score. Because anxiolytics/hypnotics might have a detrimental influence on cognitive function, we strongly suggest that the use of anxiolytics/hypnotics be reduced in schizophrenics as much as possible. Crown Copyright (C) 2009 Published by Elsevier Ireland Ltd on behalf of the Japan Neuroscience Society. All rights reserved.
  • Taro Kishi, Masatsugu Moriwaki, Tsuyoshi Kitajima, Kunihiro Kawashima, Tomo Okochi, Yasuhisa Fukuo, Osamu Furukawa, Hiroshi Naitoh, Kiyoshi Fujita, Nakao Iwata
    PSYCHOPHARMACOLOGY 209(2) 185-190 2010年4月  査読有り
    Studies have also shown that differences in the kind of the antipsychotics influenced disruption of the sensorimotor gating system, including prepulse inhibition (PPI), acoustic startle reflex (ASR), and habituation (HAB). We investigated the influence on startle response in chronic schizophrenia in 20 patients with schizophrenia taking risperidone, 21 patients with schizophrenia taking olanzapine, and 20 patients with schizophrenia taking aripiprazole. The patients who participated in this study were on maintenance therapy with only one antipsychotic drug for 4 months. We performed the test for the association between all PPI measures (ASR, HAB, and PPI at prepulse sound pressure intensities of 82, 86, and 90 dB) and each the risperidene, olanzapine, and aripiprazole groups, with analysis of covariance (ANCOVA; using age, duration of illness, and daily dose of the antipsychotic as covariates). Also, when significant difference was detected in ANCOVA, the differences of PPI measures between every pairs of two drug groups were tested as a post hoc analysis with the use of t test and Bonferroni&apos;s correction of multiple tests. We found that PPI90 showed significant differences with ANCOVA among patients with schizophrenia taking each of the antipsychotics. When we performed a post hoc analysis for PPI90, the value was higher in the aripiprazole group than in the olanzapine group and higher in the risperidone group than in the olanzapine group. Aripiprazole and risperidone may improve PPI90. ASR, HAB, PPI82, and PPI86 were no different among the Japanese schizophrenic patient groups with different antipsychotics.
  • Akiko Okuda, Taro Kishi, Tomo Okochi, Masashi Ikeda, Tsuyoshi Kitajima, Tomoko Tsunoka, Takenori Okumukura, Yasuhisa Fukuo, Yoko Kinoshita, Kunihiro Kawashima, Yoshio Yamanouchi, Toshiya Inada, Norio Ozaki, Nakao Iwata
    NEUROMOLECULAR MEDICINE 12(1) 78-85 2010年3月  査読有り
    Several investigations have reported that the translin-associated factor X gene (TSNAX)/disrupted-inschizophrenia-1 gene (DISC1) was associated with major psychiatric disorders including schizophrenia, bipolar disorder ( BP), and major depressive disorder (MDD). TSNAX is located immediately upstream of DISC1, and has been shown to undergo intergenic splicing with DISC1. It thus may also be influenced by translocation. To our knowledge, there are no reported gene-based association analyses between TSNAX and mood disorders in the Japanese population. We conducted a case-control study of Japanese samples (158 bipolar patients, 314 major depressive disorder patients, and 811 controls) with three tagging SNPs in TSNAX, selected using HapMap database. In addition, we performed an association analysis between TSNAX and the efficacy of fluvoxamine treatment in 120 Japanese patients with MDD. The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. We found an association between rs766288 in TSNAX and female MDD in the allele/genotype analysis. However, we did not find any association between TSNAX and BP or the fluvoxamine therapeutic response in MDD in the allele/genotype analysis or haplotype analysis. Our results suggest that rs766288 in TSNAX may play a role in the pathophysiology of female MDD in the Japanese population. A replication study using larger samples may be required for conclusive results, since our sample size was small.
  • Taro Kishi, Tomoko Tsunoka, Masashi Ikeda, Tsuyoshi Kitajima, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Yoshio Yamanouchi, Yoko Kinoshita, Hiroshi Ujike, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    NEUROPHARMACOLOGY 58(2) 452-456 2010年2月  査読有り
    Background: Several investigations have reported associations the serotonin 1A (5-HT1A) receptor to schizophrenia and psychotic disorders, making 5-HT1A receptor gene (HTR1A) an adequate candidate gene for the pathophysiology of schizophrenia and methamphetamine (METH)-induced psychosis. Huang and colleagues reported that rs6295 in HTR1A was associated with schizophrenia. The symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia. It may indicate that METH-induced psychosis and schizophrenia have common susceptibility genes. In support of this hypothesis, we reported that the V-act murine thymoma viral oncogene homologue I (AKT1) gene was associated with METH-induced psychosis and schizophrenia in the Japanese population. Furthermore, we conducted an analysis of the association of HTR1A with METH-induced psychosis. Method: Using one functional SNP (rs6295) and one tagging SNP (rs878567), we conducted a genetic association analysis of case-control samples (197 METH-induced psychosis patients and 337 controls) in the Japanese population. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients. Results: Rs878567 was associated with METH-induced psychosis patients in the allele/genotype-wise analysis. Moreover, this significance remained after Bonferroni correction. In addition, we detected an association between rs6295 and rs878567 in HTR1A and METH-induced psychosis patients in the haplotype-wise analysis. Although we detected an association between rs6295 and METH-induced psychosis patients, this significance disappeared after Bonferroni correction. Conclusion: HTR1A may play an important role in the pathophysiology of METH-induced psychosis in the Japanese population. However, because we did not perform a mutation scan of HTR1A, a replication study using a larger sample may be required for conclusive results. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
  • Masashi Ikeda, Yasuyuki Tomita, Akihiro Mouri, Minori Koga, Tomo Okochi, Reiji Yoshimura, Yoshio Yamanouchi, Yoko Kinoshita, Ryota Hashimoto, Hywel J. Williams, Masatoshi Takeda, Jun Nakamura, Toshitaka Nabeshima, Michael J. Owen, Michael C. O'Donovan, Hiroyuki Honda, Tadao Arinami, Norio Ozaki, Nakao Iwata
    BIOLOGICAL PSYCHIATRY 67(3) 263-269 2010年2月  査読有り
    Background: Pharmacogenomic approaches based on genomewide sets of single nucleotide polymorphisms (SNPs) are now feasible and offer the potential to uncover variants that influence drug response. Methods: To detect potential predictor gene variants for risperidone response in schizophrenic subjects, we performed a convergent analysis based on 1) a genomewide (100K SNP) SNP pharmacogenetic study of risperidone response and 2) a global transcriptome study of genes with mRNA levels influenced by risperidone exposure in mouse prefrontal cortex. Results: Fourteen genes were highlighted as of potential relevance to risperidone activity in both studies: ATP2B2, HS3ST2, UNC5C, BAG3, PDE7B, PAICS, PTGFRN, NR3C2, ZBTB20, ST6GAL2, PIP5K1B, EPHA6, KCNH5, and AJAP1. The SNPs related to these genes that were associated in the pharmacogenetic study were further assessed for evidence for association with schizophrenia in up to three case-control series comprising 1564 cases and 3862 controls in total (Japanese [JPN] 1st and 2nd samples and UK sample). Of 14 SNPs tested, one (rs9389370) in PDE7B showed significant evidence for association with schizophrenia in a discovery sample (p(allele) = .026 in JPN_1st, two-tailed). This finding replicated in a joint analysis of two independent case-control samples (PJPN-2nd+UK = .008, one-tailed, uncorrected) and in all combined data sets (p(all) =.0014, two-tailed, uncorrected and p(all) = .018, two-tailed, Bonferroni correction). Conclusions: We identified novel candidate genes for treatment response to risperidone and provide evidence that one of these additionally may confer susceptibility to schizophrenia. Specifically, PDE7B is an attractive candidate gene, although evidence from integrated methodology, including pharmacogenomics, pharmacotranscriptomic, and case-control association approaches.
  • Masashi Ikeda, Branko Aleksic, George Kirov, Yoko Kinoshita, Yoshio Yamanouchi, Tsuyoshi Kitajima, Kunihiro Kawashima, Tomo Okochi, Taro Kishi, Irina Zaharieva, Michael J. Owen, Michael C. O&apos;Donovan, Norio Ozaki, Nakao Iwata
    BIOLOGICAL PSYCHIATRY 67(3) 283-286 2010年2月  査読有り
    Background: Copy number variants (CNVs) have been shown to increase the risk to develop schizophrenia. The best supported findings are at 1q21.1, 15q11.2, 15q13.3, and 22q11.2 and deletions at the gene neurexin 1 (NRXN1). Methods: In this study, we used Affymetrix 5.0 arrays to investigate the role of rare CNVs in 575 patients with schizophrenia and 564 control subjects from Japan. Results: There was a nonsignificant trend for excess of rare CNVs in schizophrenia (p = .087); however, we did not confirm the previously implicated association for very large CNVs (&gt;500 kilobase [kb]) in this population. We provide support for three previous findings in schizophrenia, as we identified one deletion in a case at 1q21.1, one deletion within NRXN1, and four duplications in cases and one in a control subject at 16p13.1, a locus first implicated in autism and later in schizophrenia. Conclusions: In this population, we support some of the previous findings in schizophrenia but could not find an increased burden of very large (&gt;500 kb) CNVs, which was proposed recently. However, we provide support for the role of CNVs at 16p13.1, 1q21.1, and NRXN1.
  • Takenori Okumura, Taro Kishi, Tomo Okochi, Masashi Ikeda, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomoko Tsunoka, Toshiya Inada, Norio Ozaki, Nakao Iwata
    NEUROPSYCHOBIOLOGY 61(2) 57-63 2010年  査読有り
    Background/Aim: Nitric oxide has been reported to play a role in neural transmitter release and N-methyl-D-aspartate receptor activation, as well as to be related to oxidative stress. Abnormalities in both of these mechanisms are thought to be involved in the pathophysiology of mood disorders including major depressive disorder (MDD) and bipolar disorder (BP). In addition, several lines of evidence support an association between abnormalities in neuronal nitric oxide synthases (nNOS) and mood disorders. Therefore, we studied the association of nNOS gene (NOS1) and mood disorders and the efficacy of fluvoxamine treatment in Japanese MDD patients. Materials and Methods: Using a single nucleotide polymorphism (SNP; rs41279104, also called ex1c), we conducted a genetic association analysis of case-control samples (325 MDD patients, 154 BP patients and 807 controls) in the Japanese population. In addition, we performed an association analysis between NOS1 and the efficacy of fluvoxamine treatment in 117 MDD patients. We defined a clinical response as a decrease of more than 50% in baseline SIGH-D (Structured Interview Guide for the Hamilton Rating Scale for Depression) score within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. Results: We did not detect a significant association between NOS1 and MDD, BP or the fluvoxamine therapeutic response in MDD in allele/genotype-wise analysis. Conclusions: We did not detect an association between only one marker (rs41279104) in NOS1 and Japanese mood disorder patients and fluvoxamine response, but sample sizes were probably too small to allow a meaningful test. Moreover, because we did not perform an association analysis based on linkage disequilibrium and a mutation scan of NOS1, a replication of the study using a larger sample and based on linkage disequilibrium may be required for conclusive results. Copyright (C) 2009 S. Karger AG, Basel
  • Masatsugu Moriwaki, Taro Kishi, Hidetoshi Takahashi, Ryota Hashimoto, Kunihiro Kawashima, Tomo Okochi, Tsuyoshi Kitajima, Osamu Furukawa, Kiyoshi Fujita, Masatoshi Takeda, Nakao Iwata
    NEUROSCIENCE RESEARCH 65(3) 259-262 2009年11月  査読有り
    Prepulse inhibition (PPI) deficit. the acoustic startle reflex (ASR) and habituation (HAB) impairment are considered to be endophenotypes for schizophrenia. The recent two studies have reported that a PPI deficit was detected in Japanese schizophrenic patients. We replicated that study using larger samples (115 schizophrenic patients and 111 normal controls) than the original study and a method same as original study. A startle response monitoring system was used to deliver acoustic startle stimuli, and to record and score the electromyographic activity of the orbicularis oculi muscle. We evaluated the startle measures of mean magnitude of ASR, HAB, and PPI at prepulse sound pressure intensities of 82 dB (PPI82),86 dB (PPI86), and 90 dB (PPI90) ASR was significantly different between schizophrenic patients and controls HAB and all PPI session data from schizophrenic patients were significantly lower than in controls. in addition, we detected significant differences for ASR, HAB and each PPI (82, 86 and 90 dB) between schizophrenic patients and controls with the use of multiple regression analysis. The gender and smoking state were not correlated with ASR. HAB or any PPI in multiple regression analysis. In conclusion, we were able to replicate the finding of HAB impairment and PPI deficit in chronic Japanese schizophrenic patients (C) 2009 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved
  • Taro Kishi, Tomoko Tsunoka, Masashi Ikeda, Kunihiro Kawashima, Tomo Okochi, Tsuyoshi Kitajima, Yoko Kinoshita, Takenori Okumura, Yoshio Yamanouchi, Toshiya Inada, Norio Ozaki, Nakao Iwata
    JOURNAL OF HUMAN GENETICS 54(11) 629-633 2009年11月  査読有り
    Several genetic studies have shown an association between the 5-HT1A receptor gene (HTR1A) and major depressive disorder (MDD); however, results have been rather inconsistent. Moreover, to our knowledge, no association study on HTR1A and MDD in the Japanese population has been reported. Therefore, to evaluate the association between HTR1A and MDD, we conducted a case-control study of Japanese population samples with two single-nucleotide polymorphisms (SNPs), including rs6295 (C-1019G) in HTR1A. In addition, we conducted a meta-analysis of rs6295, which has been examined in other papers. Using one functional SNP (rs6295) and one tagging SNP (rs878567) selected with the HapMap database, we conducted a genetic association analysis of case-control samples (331 patients with MDD and 804 controls) in the Japanese population. Seven population-based association studies, including this study, met our criteria for the meta-analysis of rs6295. We found an association between rs878567 and Japanese MDD patients in the allele-wise analysis, but the significance of this association did not remain after Bonferroni&apos;s correction. We also did not detect any association between HTR1A and MDD in the allele/genotype-wise or haplotype-wise analysis. On the other hand, we detected an association between rs6295 and MDD in the meta-analysis (P(Z)=0.0327). In an explorative analysis, rs6295 was associated with Asian MDD patients after correction for multiple testing (P(Z)=0.0176), but not with Caucasian MDD patients (P(Z)=0.138). Our results suggest that HTR1A may not have a role in the pathophysiology of Japanese MDD patients. On the other hand, according to the meta-analysis, HTR1A was associated with MDD patients, especially in the Asian population. Journal of Human Genetics (2009) 54, 629-633; doi:10.1038/jhg.2009.84; published online 4 September 2009
  • Taro Kishi, Tsuyoshi Kitajima, Masashi Ikeda, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Tomoko Tsunoka, Toshiya Inada, Norio Ozaki, Nakao Iwata
    EUROPEAN ARCHIVES OF PSYCHIATRY AND CLINICAL NEUROSCIENCE 259(5) 293-297 2009年8月  査読有り
    Recently the clock genes have been reported to play some roles in neural transmitter systems, including the dopamine system, as well as to regulate circadian rhythms. Abnormalities in both of these mechanisms are thought to be involved in the pathophysiology of major mental illness such as schizophrenia and mood disorders including bipolar disorder (BP) and major depressive disorder (MDD). Recent genetic studies have reported that CLOCK, one of the clock genes, is associated with these psychiatric disorders. Therefore, we investigated the association between the six tagging SNPs in CLOCK and the risk of these psychiatric disorders in Japanese patients diagnosed with schizophrenia (733 patients), BP (149) and MDD (324), plus 795 Japanese controls. Only one association, with schizophrenia in females, was detected in the haplotype analysis (P = 0.0362). However, this significance did not remain after Bonferroni correction (P = 0.0724). No significant association was found with BP and MDD. In conclusion, we suggest that CLOCK may not play a major role in the pathophysiology of Japanese schizophrenia, BP and MDD patients. However, it will be important to replicate and confirm these findings in other independent studies using large samples.
  • Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Tomoko Tsunoka, Takenori Okumura, Toshiya Inada, Hiroshi Ujike, Mitsuhiko Yamada, Naohisa Uchimura, Ichiro Sora, Masaomi Iyo, Norio Ozaki, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 33(5) 895-898 2009年8月  査読有り
    Background: A recent study reported an association between rs2234693, which influences enhancer activity levels in estrogen receptor alpha gene (ESR1), and schizophrenia. This study reported that schizophrenic patients with the CC genotype have significantly lower ESR1 mRNA levels in the prefrontal cortex than patients with other genotypes. The symptoms of methamphetamine induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an association analysis of rs2234693 with Japanese methamphetamine induced psychosis patients. Method: Using rs2234693, we conducted a genetic association analysis of case-control samples (197 methamphetamine induced psychosis patients and 197 healthy controls). The age and sex of the control subjects did not differ from those of the methamphetamine induced psychosis patients. Results: We detected a significant association between ESR1 and methamphetamine induced psychosis patients in allele/genotype-wise analysis. For further interpretation of these associations, we performed single marker analysis of subjects divided by sex. Rs2234693 was associated with male methamphetamine induced psychosis. Discussion: Our results suggest that rs2234693 in ESR1 may play a role in the pathophysiology of Japanese methamphetamine induced psychosis patients. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.
  • Tomoko Tsunoka, Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Toshiya Inada, Norio Ozaki, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 33(5) 875-879 2009年8月  査読有り
    Background: Several lines of evidence implicate abnormalities in glutamate neural transmission in the pathophysiology of mood disorders, including major depressive disorder (MDD) and bipolar disorder (BP). Preclinical antidepressant effects were also reported for group 11 metabotropic glutamate receptor (Group 11 mGluRs) antagonists show dose-dependent antidepressant-like effects in murine models of depression. Also, it has been suggested that abnormalities in the hypothalamic-pituitary-adrenal axis and serotonergic neural transmission are important mechanisms in the pathophysiology of mood disorders. Group 11 mGluRs play an important role in regulating the function of these mechanisms. From these results, it has been suggested that abnormalities in Group 11 mGluRs might be involved in the pathophysiology of mood disorders, including (MDD) and BP, and may influence the clinical response to treatment with SSRIs in MDD. Therefore, we studied the association between Group 11 mGluR genes (GRM2 and GRM3) and mood disorders and the efficacy of fluvoxamine treatment in Japanese MDD patients. Materials and methods: Using three tagging SNPs in GRM2 and an SNP (rs6465084) reported functional variant in GRM3, we conducted a genetic association analysis of case-control samples (325 MDD patients, 155 BP Patients and 802 controls) in the Japanese population.. In addition, we performed an association analysis of GRM2 and GRM3 and the efficacy of fluvoxamine treatment in 117 Japanese patients with MDD. The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks, Results: We found an association between rs6465084 in GRM3 and MDD in the allele-wise analysis after Bonferroni's correction (P-value = 0.0371). However, we did not find any association between GRM3 and BP or the fluvoxamine therapeutic response in MDD in the allele/genotype-wise analysis. We also did not detect any association between GRM2 and MDD, BP or the fluvoxamine therapeutic response in MDD in the allele/genotype-wise or haplotype-wise analysis. Discussion: We detected an association between only one marker (rs6465084) in GRM3 and Japanese MDD patients. However, because we did not perform an association analysis based on ID and a mutation scan of GRM3, a replication study using a larger sample and based on LD may be required for conclusive results. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.
  • Tomo Okochi, Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoko Kinoshita, Kunihiro Kawashima, Takenori Okumura, Tomoko Tsunoka, Toshiya Inada, Mitsuhiko Yamada, Naohisa Uchimura, Masaomi Iyo, Ichiro Sora, Norio Ozaki, Hiroshi Ujike, Nakao Iwata
    PROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY 33(5) 903-905 2009年8月  査読有り
    The neuregulin 1 gene (NRG1) has been identified as a candidate gene for schizophrenia in a linkage study in the Icelandic population. Recent evidence also suggested that it might be related to the neurodevelopmental hypothesis and glutamate hypothesis for schizophrenia. Because the symptomatology of methamphetamine (METH) use disorder with accompanying psychosis is similar to that of patients with schizophrenia, NRG1 is an appropriate candidate gene for METH-induced psychosis. We conducted a case-control association study between NRG1 and MEM-induced psychosis in a Japanese population (184 subjects with MEM-induced psychosis and 534 controls). Written informed consent was obtained from each subject. We selected four SNPs (SNP8NRG221533, SNP8NRG241930, SNP8NRG243177, and rs3924999) in NRG1 from previous reports. No significant association was found between NRG1 and METH-induced psychosis in the allele/genotype-wise or haplotype-wise analyses. In conclusion, NRG1 might not contribute to the risk of METH-induced psychosis in the Japanese population. (C) 2009 Elsevier Inc. All rights reserved.
  • Taro Kishi, Masashi Ikeda, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Tomoko Tsunoka, Toshiya Inada, Norio Ozaki, Nakao Iwata
    PSYCHIATRIC GENETICS 19(4) 217-218 2009年8月  査読有り
  • Kunihiro Kawashima, Masashi Ikeda, Taro Kishi, Tsuyoshi Kitajima, Yoshio Yamanouchi, Yoko Kinoshita, Tomo Okochi, Branko Aleksic, Makoto Tomita, Takeya Okada, Hiroshi Kunugi, Toshiya Inada, Norio Ozaki, Nakao Iwata
    SCHIZOPHRENIA RESEARCH 112(1-3) 72-79 2009年7月  査読有り
    A variety of evidence suggests brain-derived neurotrophic factor (BDNF) as a candidate gene for schizophrenia, and several genetic studies have shown a significant association between the disease and certain SNPs within BDNF (specifically, Val66Met and C270T). According to a recent study, the functional microsatellite marker BDNF-LCPR (BDNF-linked complex polymorphic region), which affects the expression level of BDNF, is associated with bipolar disorder. The goals of our current study were to 1) evaluate the quality of HapMap-based linkage disequilibrium (LD) tagging of BDNF-LCPR, 2) examine whether these tagging SNPs are associated with schizophrenia in a Japanese population, and 3) conduct a meta-analysis of the two most extensively studied polymorphisms: Val66Met and C270T. We genotyped eight tagging SNPs, including Val66Met and C270T. Our LID evaluation showed that BDNF-LCPR could be represented by these tagging SNPs in controls (with 73.5% allelic coverage). However, the functional A1 allele was not captured due to its low minor allele frequency (2.2%). In a case-control study (1117 schizophrenics and 1102 controls), no association was found in single-marker or multimarker analysis. Moreover, in a meta-analysis, the Val66Met polymorphism was not associated with schizophrenia, whereas C270T showed a trend for association in a fixed model (p = 0.036), but not in a random model (p = 0.053). From these findings, we conclude that if BDNF is indeed associated with schizophrenia, the A1 allele in BDNF-LCPR would be the most promising candidate. Further LD evaluation, as well as an association study in which BDNF-LCPR is genotyped directly, would be required for a more conclusive result. (C) 2009 Elsevier B.V. All rights reserved.
  • Taro Kishi, Tsuyoshi Kitajima, Masashi Ikeda, Yoshio Yamanouchi, Yoko Kinoshita, Kunihiro Kawashima, Tomo Okochi, Takenori Okumura, Tomoko Tsunoka, Norio Ozaki, Nakao Iwata
    NEUROMOLECULAR MEDICINE 11(2) 53-57 2009年6月  査読有り
    Recent studies have shown that selective serotonin reuptake inhibitors (SSRIs) have circadian properties, suggesting that the antidepressive action of SSRIs may also be attributable to circadian mechanisms. Another study reported an association between clock gene (CLOCK) and improvements in insomnia symptoms from SSRIs treatment. Therefore, we examined the association between CLOCK and the efficacy of fluvoxamine treatment in 121 patients with Japanese major depressive disorder (MDD). The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a therapeutic response as a decrease of more than a 50% in baseline SIGH-D within 8 weeks, and clinical remission as a SIGH-D score of less than seven at 8 weeks. We selected three tagging SNPs in CLOCK for the subsequent statistical association analysis. We detected a significant association between rs3736544, a synonymous polymorphism in exon 20, and the fluvoxamine therapeutic response in MDD in the allele/genotype-wise analyses. In addition, remission with fluvoxamine was also significantly associated with rs3736544. These associations remained significant after Bonferroni correction. Moreover, haplotype analysis findings supported these significant associations, which appeared to be due mainly to rs3736544, in the fluvoxamine therapeutic remission. Our results indicate that CLOCK genotype may be a predictor of fluvoxamine treatment response in Japanese MDD. However, our sample size was small, and a replication study using larger samples may be required for conclusive results.

MISC

 15
  • 岸 太郎, 松田 勇紀, 森脇 正詞, 川島 邦裕, 大竹 洋一郎, 向井 智彦, 大河内 智, 平野 茂樹, 田伏 英晶, 赤松 拡, 藤田 潔, 岩田 仲生
    Depression Journal 2(1) 28-31 2014年4月  
    日本人大うつ病性障害患者に対するエスシタロプラムの有効性、認容性について検討した。エスシタロプラム群(ESC群)21例、パロキセチン徐放製剤群(PAR群)23例を対象とした。ESC群、PAR群において、反応率は4週後57.1%、60.9%、8週後53.4%、42.4%、寛解率は4週後23.8%、17.4%、8週後40.0%、27.8%であった。ESC群、PAR群において、すべての要因による中断率は、4週後19.1%、43.5%、8週後23.8%、47.8%で、ESC群で低い傾向を認めた。副作用による中断率は、4週後9.5%、9、1%、8週後9.5%、8.7%で、有意差は認めなかった。効果不十分による中断率はESC群は4、8週後とも0%であったが、PAR群は4週後17.4%、8週後21.7%で、ESC群が有意に低かった。死亡、心血管イベントを含む重篤な有害事象は両群とも認めなかった。
  • 大河内 智, 古川 修, 藤田 潔, 岩田 仲生
    臨床精神薬理 16(4) 555-564 2013年4月  
    初発、再発(1ヵ月以内で抗精神病薬の内服歴がない)の統合失調症患者におけるblonanserin(BNS)の単剤治療の有用性について検討した。急性期症状を呈した初発あるいは再発統合失調症患者8例を対象に、8週間のオープンラベル試験を行った。BNS投与終了時の評価において8例中6例の患者で改善効果が得られた。8週間の試験を完了できた症例は4例であった。PANSS、CGI評価において、いずれも投与開始2週目時点で改善が認められた。特にPANSS-ECにおいては、投与開始1週の時点でベースラインからの改善が得られており、投与開始早期での治療反応性が示された。試験期間を通じて重篤な副作用は認められなかったが、錐体外路症状(EPS)が3例に認められ、その内2例(初発症例)はBNSの減量や抗パーキンソン薬併用といった対処を行ったが、EPSの改善は認められず中止に至っている。今回の結果から初発例では8〜16mg/日投与が適正な初期治療用量で、増量は慎重に行うことが望ましいと考えられた。(著者抄録)
  • 岩田 仲生, 大河内 智
    Pharma Medica 30(3) 197-199 2012年3月  
    drugナイーブな急性期統合失調症患者8例(男性5例、女性3例、平均年齢37.3歳)を対象に、8週間のオープンラベル試験にてブロナンセリンの有効性と安全性を検討した。その結果、1)8週の試験を継続できたのは4例であった。残り4例中1例は症状改善で転院希望により、他の1例は効果不十分、2例は副作用により脱落となった。2)治療反応率は2週目4/8例、4週目3/5例で、8週目は継続できた4例とも改善しているため4/4例であった。だが、エンドポイントは6/8例であった。3)PANSS-ECスコアでは1週目ですでに改善がみられ、サブスコールスコアでは特に陽性症状で強い改善傾向が示された。CGIも2週目時点で改善が得られ、試験開始時点では半数以上が「重度異常」であったのに対し、エンドポイントでは半数以上が「軽度異常」となった。4)副作用は椎体外路症状が3例にみられ、1例は抗パーキンソン病薬併用にて軽減・完遂したものの、2例は抗パーキンソン薬併用にても改善せず、試験の中止となった。
  • 鶴田 敬子, 戸澤 香里, 福生 泰久, 大河内 智, 岸 太郎, 池田 匡志, 亀井 浩行, 尾崎 紀夫, 岩田 仲生
    日本医療薬学会年会講演要旨集 21 331-331 2011年9月9日