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
  • Taro Kishi, Yuki Matsuda, Nakao Iwata
    PloS one 9(2) e88049 2014年  査読有り
    BACKGROUND: The present study aimed to evaluate cardiometabolic risks [weight gain, blood lipid levels (total cholesterol and triglycerides), blood glucose levels, hemoglobin A1c (HbA1c) levels, and corrected QT interval (QTc) prolongation] associated with the use of blonanserin and perospirone versus other antipsychotics in the management of patients with schizophrenia. METHOD: We conducted a systematic review and meta-analysis of patient data from randomized controlled trials comparing blonanserin or perospirone with other antipsychotics. RESULTS: In total, 4 blonanserin studies (n = 1080) were identified [vs. risperidone (2 studies, n = 508); vs. haloperidol (2 studies, n = 572)]. Blonanserin produced less weight gain compared with risperidone (weighted mean difference = -0.86, 95% confidence intervals = -1.36 to -0.36, p = 0.0008; 2 studies, 480 patients). However, no significant differences were observed in blood lipid, glucose, and HbA1c levels or QTc prolongation between blonanserin and risperidone or haloperidol. For perospirone studies, 5 studies [562 adult patients with schizophrenia randomized to perospirone (n = 256), olanzapine (n = 20), quetiapine (n = 28), risperidone (n = 53), aripiprazole (n = 49), haloperidol (n = 75), or mosapramine (n = 81)] were identified. Perospirone did not differ from other antipsychotics with regard to weight gain and total cholesterol levels. CONCLUSIONS: Our results suggest that blonanserin is associated with a lower of weight gain compared with other antipsychotics. Because the number of studies was small, additional controlled clinical trials with larger number of patients are indicated.
  • Reiji Yoshimura, Taro Kishi, Hikaru Hori, Asuka Katsuki, Atsuko Sugita-Ikenouchi, Wakako Umene-Nakano, Kiyokazu Atake, Nakao Iwata, Jun Nakamura
    Psychiatry investigation 11(1) 84-8 2014年1月  査読有り
    OBJECTIVE: It is important to predict a response to an antidepressant in early time after starting the antidepressant. We previously reported that serum brain-derived neurotrophic factor (BDNF) levels in responders to treatment with antidepressants were increased, whereas, those in nonresponders were not. Therefore, we hypothesized that the changes in serum levels of BDNF from baseline (T0) to 4 weeks (T4) after treatment with selective serotonin reuptake inhibitors (SSRIs) predict the response to the treatment at 8 weeks (T8) in depressed patients. To confirm the hypothesis, we measured serum BDNF at T0, T4, and T8 during the treatment with SSRIs (paroxetine, sertraline, and fluvoxamine). METHODS: One hundred fifty patients (M/F; 51/99, age; 50.4±15.1 years) met major depressive disorder (MDD) using by DSM-IV-TR enrolled in the present study. We measured serum BDNF concentrations at T0, T4, and T8 in patients with MDD treated with SSRIs. RESULTS: The changes in serum BDNF, age, sex, dose of SSRIs, and HAMD-17 score did not predict the response to SSRIs at T8. CONCLUSION: These results suggest that the changes in serum BDNF levels from T0 to T4 could not predict the subsequent responses to SSRIs at T8.
  • Hayashi K, Yoshimura R, Kakeda S, Kishi T, Abe O, Umene-Nakano W, Katsuki A, Hori H, Ikenouchi-Sugita A, Watanabe K, Ide S, Ueda I, Moriya J, Iwata N, Korogi Y, Kubicki M, Nakamura J
    Neuropsychiatric disease and treatment 10 1183-90 2014年  査読有り
  • Yoshimura R, Kishi T, Hori H, Atake K, Katsuki A, Nakano-Umene W, Ikenouchi-Sugita A, Iwata N, Nakamura J
    Annals of general psychiatry 13 19-19 2014年  査読有り
  • Mikio Kido, Yukako Nakamura, Kiyotaka Nemoto, Tsutomu Takahashi, Branko Aleksic, Atsushi Furuichi, Yumiko Nakamura, Masashi Ikeda, Kyo Noguchi, Kozo Kaibuchi, Nakao Iwata, Norio Ozaki, Michio Suzuki
    PloS one 9(8) e103571 2014年  査読有り
    BACKGROUND: YWHAE is a possible susceptibility gene for schizophrenia that encodes 14-3-3epsilon, a Disrupted-in-Schizophrenia 1 (DISC1)-interacting molecule, but the effect of variation in its genotype on brain morphology remains largely unknown. METHODS: In this voxel-based morphometric magnetic resonance imaging study, we conducted whole-brain analyses regarding the effects of YWHAE single-nucleotide polymorphisms (SNPs) (rs28365859, rs11655548, and rs9393) and DISC1 SNP (rs821616) on gray matter volume in a Japanese sample of 72 schizophrenia patients and 86 healthy controls. On the basis of a previous animal study, we also examined the effect of rs28365859 genotype specifically on hippocampal volume. RESULTS: Whole-brain analyses showed no significant genotype effect of these SNPs on gray matter volume in all subjects, but we found significant genotype-by-diagnosis interaction for rs28365859 in the left insula and right putamen. The protective C allele carriers of rs28365859 had a significantly larger left insula than the G homozygotes only for schizophrenia patients, while the controls with G allele homozygosity had a significantly larger right putamen than the C allele carriers. The C allele carriers had a larger right hippocampus than the G allele homozygotes in schizophrenia patients, but not in healthy controls. No significant interaction was found between rs28365859 and DISC1 SNP on gray matter volume. CONCLUSIONS: These different effects of the YWHAE (rs28365859) genotype on brain morphology in schizophrenia and healthy controls suggest that variation in its genotype might be, at least partly, related to the abnormal neurodevelopment, including in the limbic regions, reported in schizophrenia. Our results also suggest its specific role among YWHAE SNPs in the pathophysiology of schizophrenia.
  • Taro Kishi, Yuki Matsuda, Kiyoshi Fujita, Nakao Iwata
    Neuropsychiatric disease and treatment 10 1861-6 2014年  査読有り
    BACKGROUND: Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia in Japan and Korea. The present study aimed to examine early prediction of blonanserin in patients with schizophrenia. METHODS: An 8-week, prospective, single-arm, flexible-dose clinical trial of blonanserin in patients with schizophrenia was conducted under real-world conditions. The inclusion criteria were antipsychotic naïve, and first-episode schizophrenia patients or schizophrenia patients with no consumption of any antipsychotic medication for more than 4 weeks before enrollment in this study. The positive predictive value, negative predictive value, sensitivity, specificity, and predictive power were calculated for the response status at week 4 to predict the subsequent response at week 8. RESULTS: Thirty-seven patients were recruited (56.8% of them had first-episode schizophrenia), and 28 (75.7%) completed the trial. At week 8, blonanserin was associated with a significant improvement in the Positive and Negative Syndrome Scale (PANSS) total score (P<0.0001) and in positive (P<0.0001), negative (P<0.0001), and general subscale scores (P<0.0001). In terms of percentage improvement of PANSS total scores from baseline to week 8, 64.9% of patients showed a ≥20% reduction in the PANSS total score and 48.6% showed a ≥30% reduction. However, 8.1% of patients experienced at least one adverse event. Using the 20% reduction in the PANSS total score at week 4 as a definition of an early response, the negative predictive values for later responses (ie, reductions of ≥30 and ≥40 in the PANSS total scores) were 88.9% and 94.1%, respectively. The specificities were 80.0% and 51.6%, respectively. CONCLUSION: Our results suggest that the blonanserin response at week 4 could predict the later response at week 8.
  • Jingrui Xing, Chenyao Wang, Hiroki Kimura, Yuto Takasaki, Shohko Kunimoto, Akira Yoshimi, Yukako Nakamura, Takayoshi Koide, Masahiro Banno, Itaru Kushima, Yota Uno, Takashi Okada, Branko Aleksic, Masashi Ikeda, Nakao Iwata, Norio Ozaki
    PloS one 9(11) e112531 2014年  査読有り
    BACKGROUND: The PTPRA gene, which encodes the protein RPTP-α, is critical to neurodevelopment. Previous linkage studies, genome-wide association studies, controlled expression analyses and animal models support an association with both schizophrenia and autism spectrum disorders, both of which share a substantial portion of genetic risks. METHODS: We sequenced the protein-encoding areas of the PTPRA gene for single nucleotide polymorphisms or small insertions/deletions (InDel) in 382 schizophrenia patients. To validate their association with the disorders, rare (minor allele frequency <1%), missense mutations as well as one InDel in the 3'UTR region were then genotyped in another independent sample set comprising 944 schizophrenia patients, 336 autism spectrum disorders patients, and 912 healthy controls. RESULTS: Eight rare mutations, including 3 novel variants, were identified during the mutation-screening phase. In the following association analysis, L59P, one of the two missense mutations, was only observed among patients of schizophrenia. Additionally, a novel duplication in the 3'UTR region, 174620_174623dupTGAT, was predicted to be located within a Musashi Binding Element. MAJOR CONCLUSIONS: No evidence was seen for the association of rare, missense mutations in the PTPRA gene with schizophrenia or autism spectrum disorders; however, we did find some rare variants with possibly damaging effects that may increase the susceptibility of carriers to the disorders.
  • Ayu Shimasaki, Kenji Kondo, Takeo Saito, Kosei Esaki, Yasuyo Otsuka, Keiko Mano, Masashi Ikeda, Nakao Iwata
    PloS one 9(12) e115135 2014年  査読有り
    Genome-wide association studies (GWASs) have identified a number of susceptibility genes for schizophrenia (SCZ) and bipolar disorder (BD). However, the identification of risk genes for major depressive disorder (MDD) has been unsuccessful because the etiology of MDD is more influenced by environmental factors; thus, gene-environment (G × E) interactions are important, such as interplay with stressful life events (SLEs). We assessed the G×E interactions and main effects of genes targeting depressive symptoms. Using a case-control design, 922 hospital staff members were evaluated for depressive symptoms according to Beck Depressive Inventory (BDI; "depression" and "control" groups were classified by scores of 10 in the BDI test), SLEs, and personality. A total of sixty-three genetic variants were selected on the basis of previous GWASs of MDD, SCZ, and BD as well as candidate-gene (SLC6A4, BDNF, DBH, and FKBP5) studies. Logistic regression analysis revealed a marginally significant interaction (genetic variant × SLE) at rs4523957 (P uncorrected = 0.0034) with depression and a significant association of single nucleotide polymorphism identified from evidence of BD GWAS (rs7296288, downstream of DHH at 12q13.1) with depression as the main effect (P uncorrected = 9.4 × 10(-4), P corrected = 0.0424). We also found that SLEs had a larger impact on depression (odds ratio ∼ 3), as reported previously. These results suggest that DHH plays a possible role in depression etiology; however, variants from MDD or SCZ GWAS evidence or candidate genes showed no significant associations or minimal effects of interactions with SLEs on depression.
  • Taro Kishi, Shinji Matsunaga, Yuki Matsuda, Nakao Iwata
    Neuropsychiatric disease and treatment 10 2339-51 2014年  査読有り
    BACKGROUND: We conducted a meta-analysis of the iminodibenzyl antipsychotics carpipramine, clocapramine, and mosapramine, which are classified as second-generation antipsychotics (SGAs) for schizophrenia treatment. METHODS: We searched data that had been published in PubMed, the Cochrane Library databases, PsycINFO, CiNii, and the Japan Medical Abstracts Society up to August 29, 2014. Randomized controlled trials that compared iminodibenzyl antipsychotics with other antipsychotics in patients with schizophrenia were included. Odds ratios and standardized mean differences were evaluated. RESULTS: We included four randomized controlled trials on carpipramine (number of patients [n]=290), six on clocapramine (n=1,048), and five on mosapramine (n=986) in the meta-analysis. There were no significant differences in the response rates or in the discontinuation rates either between carpipramine and the other pooled antipsychotics or between clocapramine and the other pooled antipsychotics. On the Positive and Negative Syndrome Scale, mosapramine's positive subscale scores were superior to those of the other pooled antipsychotics (standard mean of difference =-0.22); however, on that same scale, there were no significant differences in total scores, negative scores, general subscale scores, response rates, or the discontinuation rates between mosapramine and the other pooled antipsychotics. Furthermore, the incidences of extrapyramidal symptoms and of hyperprolactinemia were significantly greater with mosapramine than with the other pooled antipsychotics. CONCLUSION: The pharmacological profiles of carpipramine and clocapramine, which are classified as SGAs, were similar to those of first-generation antipsychotics because there were no significant differences in efficacy and safety outcomes. However, mosapramine was associated with a greater risk of extrapyramidal symptoms and hyperprolactinemia than the other SGAs were, although it may be beneficial for the improvement of positive symptoms.
  • Taro Kishi, Shinji Matsunaga, Yuki Matsuda, Nakao Iwata
    NEUROPSYCHIATRIC DISEASE AND TREATMENT 10 2339-2351 2014年  査読有り
    Background: We conducted a meta-analysis of the iminodibenzyl antipsychotics carpipramine, clocapramine, and mosapramine, which are classified as second-generation antipsychotics (SGAs) for schizophrenia treatment. Methods: We searched data that had been published in PubMed, the Cochrane Library databases, PsycINFO, CiNii, and the Japan Medical Abstracts Society up to August 29, 2014. Randomized controlled trials that compared iminodibenzyl antipsychotics with other antipsychotics in patients with schizophrenia were included. Odds ratios and standardized mean differences were evaluated. Results: We included four randomized controlled trials on carpipramine (number of patients [n]=290), six on clocapramine (n=1,048), and five on mosapramine (n=986) in the meta-analysis. There were no significant differences in the response rates or in the discontinuation rates either between carpipramine and the other pooled antipsychotics or between clocapramine and the other pooled antipsychotics. On the Positive and Negative Syndrome Scale, mosapramine's positive subscale scores were superior to those of the other pooled antipsychotics (standard mean of difference =-0.22); however, on that same scale, there were no significant differences in total scores, negative scores, general subscale scores, response rates, or the discontinuation rates between mosapramine and the other pooled antipsychotics. Furthermore, the incidences of extrapyramidal symptoms and of hyperprolactinemia were significantly greater with mosapramine than with the other pooled antipsychotics. Conclusion: The pharmacological profiles of carpipramine and clocapramine, which are classified as SGAs, were similar to those of first-generation antipsychotics because there were no significant differences in efficacy and safety outcomes. However, mosapramine was associated with a greater risk of extrapyramidal symptoms and hyperprolactinemia than the other SGAs were, although it may be beneficial for the improvement of positive symptoms.
  • Kenji Hayashi, Reiji Yoshimura, Shingo Kakeda, Taro Kishi, Osamu Abe, Wakako Umene-Nakano, Asuka Katsuki, Hikaru Hori, Atsuko Ikenouchi-Sugita, Keita Watanabe, Satoru Ide, Issei Ueda, Junji Moriya, Nakao Iwata, Yukunori Korogi, Marek Kubicki, Jun Nakamura
    NEUROPSYCHIATRIC DISEASE AND TREATMENT 10 1183-1190 2014年  査読有り
    We investigated the association between the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene, the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene, and white matter changes in patients with major depressive disorder (MDD) and healthy subjects using diffusion tensor imaging (DTI). We studied 30 patients with MDD (17 males and 13 females, with mean age +/- standard deviation [SD] =44 +/- 12 years) and 30 sex-and age-matched healthy controls (17 males and 13 females, aged 44 +/- 13 years). Using DTI analysis with a tract-based spatial statistics (TBSS) approach, we investigated the differences in fractional anisotropy, radial diffusivity, and axial diffusivity distribution among the three groups (patients with the COMT gene Val158Met, those with the BDNF gene Val66Met, and the healthy subjects). In a voxel-wise-based group comparison, we found significant decreases in fractional anisotropy and axial diffusivity within the temporal lobe white matter in the Met-carriers with MDD compared with the controls (P&lt;0.05). No correlations in fractional anisotropy, axial diffusivity, or radial diffusivity were observed between the MDD patients and the controls, either among those with the BDNF Val/Val genotype or among the BDNF Met-carriers. These results suggest an association between the COMT gene Val158Met and the white matter abnormalities found in the temporal lobe of patients with MDD.
  • Taro Kishi, Yuki Matsuda, Kiyoshi Fujita, Nakao Iwata
    NEUROPSYCHIATRIC DISEASE AND TREATMENT 10 1861-1866 2014年  査読有り
    Background: Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia in Japan and Korea. The present study aimed to examine early prediction of blonanserin in patients with schizophrenia. Methods: An 8-week, prospective, single-arm, flexible-dose clinical trial of blonanserin in patients with schizophrenia was conducted under real-world conditions. The inclusion criteria were antipsychotic naive, and first-episode schizophrenia patients or schizophrenia patients with no consumption of any antipsychotic medication for more than 4 weeks before enrollment in this study. The positive predictive value, negative predictive value, sensitivity, specificity, and predictive power were calculated for the response status at week 4 to predict the subsequent response at week 8. Results: Thirty-seven patients were recruited (56.8% of them had first-episode schizophrenia), and 28 (75.7%) completed the trial. At week 8, blonanserin was associated with a significant improvement in the Positive and Negative Syndrome Scale (PANSS) total score (P&lt;0.0001) and in positive (P&lt;0.0001), negative (P&lt;0.0001), and general subscale scores (P&lt;0.0001). In terms of percentage improvement of PANSS total scores from baseline to week 8, 64.9% of patients showed a &gt;= 20% reduction in the PANSS total score and 48.6% showed a &gt;= 30% reduction. However, 8.1% of patients experienced at least one adverse event. Using the 20% reduction in the PANSS total score at week 4 as a definition of an early response, the negative predictive values for later responses (ie, reductions of &gt;30 and &gt;40 in the PANSS total scores) were 88.9% and 94.1%, respectively. The specificities were 80.0% and 51.6%, respectively. Conclusion: Our results suggest that the blonanserin response at week 4 could predict the later response at week 8.
  • Taro Kishi, Tomoya Hirota, Nakao Iwata
    European archives of psychiatry and clinical neuroscience 263(8) 633-41 2013年12月  査読有り
    We performed an updated meta-analysis of fluvoxamine add-on therapy in patients with schizophrenia treated with antipsychotics based on two previous meta-analyses (Sepehry et al., in J Clin Psychiatry 68:604-610, 2007 and Singh et al., in Br J Psychiatry J Mental Sci 197:174-179, 2010). We searched PubMed, the Cochrane Library database, and PsycINFO up to January 2013. We conducted a systematic review and meta-analysis of individual patient data from randomized controlled trials comparing fluvoxamine add-on therapy with placebo. The risk ratio (RR), 95 % confidence intervals (CI), and standardized mean difference (SMD) were calculated. Seven studies (total n = 272) were identified. These included two clozapine studies, one olanzapine study, one second-generation antipsychotic (SGA) monotherapy study, and three first-generation antipsychotics (FGAs) monotherapy studies. There were significant effect of fluvoxamine add-on therapy on overall (SMD = -0.46, CI = -0.75 to -0.16, p = 0.003, I (2) = 0 %, 5 studies, n = 180) and negative symptoms (SMD = -0.44, CI = -0.74 to -0.14, p = 0.004, I (2) = 0 %, 5 studies, n = 180). However, fluvoxamine add-on therapy showed no significant effects on positive symptoms, depressive symptoms, and discontinuations from any cause or adverse events. Fluvoxamine add-on therapy in patients primarily treated with SGAs improved overall (p = 0.02) but not negative symptoms (p = 0.31). On the other hand, fluvoxamine add-on therapy in patients primarily treated with FGAs improved both overall (p = 0.04) and negative symptoms (p = 0.004) compared with control groups. Our results suggest that fluvoxamine add-on therapy is more beneficial on the psychopathology (especially negative symptoms) than controls in patients with schizophrenia who are primarily treated with FGAs. Given that a small number of studies were included in this meta-analysis, the results should be treated with caution.
  • Yuki Matsuda, Taro Kishi, Nakao Iwata
    Journal of psychiatric research 47(12) 2018-20 2013年12月  査読有り
  • Taro Kishi, Yuki Matsuda, Nakao Iwata, Christoph U Correll
    The Journal of clinical psychiatry 74(12) e1169-80-U79 2013年12月  査読有り
    OBJECTIVE: Since cocaine and psychostimulant dependence are related to increased dopamine release, antipsychotics have been tried to reduce their reinforcing properties. A meta-analysis was undertaken to assess the efficacy and tolerability of antipsychotics in cocaine- or stimulant-dependent patients. DATA SOURCES: We searched PubMed, Cochrane Library databases, and PsycINFO from database inception until June 24, 2013, using the following keywords: (randomized OR random OR randomly) AND (placebo) AND (methylphenidate OR cocaine OR methamphetamine OR amphetamine OR 3,4-methylenedioxymethamphetamine) AND (dependence OR abuse) AND (antipsychotic OR neuroleptic OR 34 specific antipsychotic names). STUDY SELECTION: Included were randomized, placebo-controlled trials of antipsychotics lasting at least 2 weeks in patients with primary cocaine or psychostimulant dependence. Of 363 hits, we removed 316 duplicates, 20 references based on abstract/title, and 13 ineligible full-text articles, retaining 14 trials for this meta-analysis. DATA EXTRACTION: Two authors independently extracted the data. Coprimary outcomes included degree of substance use and lack of abstinence. Risk ratio (RR), 95% CI, and standardized mean difference were calculated. RESULTS: Ten studies in patients with primary cocaine dependence (risperidone = 5, olanzapine = 3, reserpine = 2; n = 562) and 4 in those with amphetamine/methamphetamine dependence (aripiprazole = 4; n = 179) were meta-analyzed (14 studies, total n = 741). When study results were pooled together, antipsychotics did not differ from placebo in regard to cocaine use days and lack of cocaine or amphetamine/methamphetamine abstinence, severity of addiction, cocaine or amphetamine/methamphetamine craving, Clinical Global Impressions-Severity of Illness (CGI-S) scores, depression, anxiety, compliance, all-cause discontinuation, and several side effects. However, antipsychotics caused more intolerability-related discontinuation than placebo (P = .0009). Individually, aripiprazole was superior to placebo in regard to CGI-S (P = .001), while olanzapine was inferior to placebo in regard to cocaine craving (P = .03) and risperidone was inferior to placebo in regard to depression (P = .002). CONCLUSIONS: Antipsychotics had no advantages over placebo in regard to cocaine use and cocaine or psychostimulant abstinence or craving, while causing more intolerability-related discontinuations.
  • Yuichiro Watanabe, Yoshimi Iijima, Jun Egawa, Ayako Nunokawa, Naoshi Kaneko, Tadao Arinami, Hiroshi Ujike, Toshiya Inada, Nakao Iwata, Hiroshi Kunugi, Masanari Itokawa, Tsukasa Sasaki, Norio Ozaki, Ryota Hashimoto, Masako Shibuya, Hirofumi Igeta, Toshiyuki Someya
    Schizophrenia research 150(2-3) 596-7 2013年11月  査読有り
  • Taro Kishi, Tomohiko Mukai, Yuki Matsuda, Masatsugu Moriwaki, Nakao Iwata
    Journal of psychiatric research 47(11) 1557-63 2013年11月  査読有り
    BACKGROUND: We performed an updated meta-analysis of noradrenalin reuptake inhibitor (NRI) augmentation therapy in patients with schizophrenia treated with antipsychotics based on a previous meta-analysis (Singh et al.). METHODS: PubMed, Cochrane Library databases, and PsycINFO citations were searched from their inception to June 10, 2013 without language restrictions. We conducted a systematic review and meta-analysis of individual patient data from randomized controlled trials comparing NRI augmentation therapy with placebo. The outcome measure for efficacy was the psychopathology of schizophrenia and the measures for safety were discontinuation rate and several side effects. We used standardized mean differences (SMD) to estimate treatment effects for continuous variables, and risk ratios (RR) for dichotomous variables, with their 95% confidence intervals (CIs). A random-effects model was used. RESULTS: Nine studies (4 atomoxetine studies, 3 reboxetine studies, 1 reboxetine-betahistine combination study and 1 mazindol study, total n=298) were identified. No statistically significant effects of NRI augmentation therapy on overall (p=0.90), positive (p=0.81), and negative (p=0.89) symptoms were found. NRI augmentation therapy was marginally superior to placebo for efficacy of depressive symptoms (SMD=-1.08, p=0.05). Dropout due to all-cause (p=0.70), inefficacy (p=0.64), or adverse events (p=0.18) was similar in both groups. NRI augmentation therapy showed a significantly lower increase or larger reduction in body weight than placebo (SMD=-0.47, p=0.03). Reboxetine augmentation was associated with less weight gain that placebo in antipsychotic treated schizophrenia patients (SMD=-0.78, p=0.0001). CONCLUSION: NRIs may exert an effect on depressive symptoms, and seem to be well-tolerated treatments.
  • Jun Ishigooka, Kazuyuki Nakagome, Tetsuro Ohmori, Nakao Iwata
    BMC psychiatry 13 243-243 2013年10月3日  査読有り
    BACKGROUND: It is desirable to establish evidence for the selection of antipsychotics from the viewpoint of recovery of social activity in individual patient with schizophrenia receiving medication. From this perspective, awareness of the importance of studies about drug effectiveness on treatment discontinuation rate, remission rate, and improvement in QOL has grown recently. In Western countries, numerous reports are available in effectiveness studies, which are related to olanzapine and risperidone primarily, whereas evidence for other second-generation antipsychotics (SGAs) is poor. In Japan, no effectiveness study has been reported: thus, it is desirable to collect data that will serve as evidence for selection of the 3 SGAs approved after olanzapine. METHODS: The present study was a long-term effectiveness study under healthcare setting in Japan. It was designed as an open-label, multicenter, randomized, comparative study involving 104-week oral treatment with 1 of the 3 drugs (aripiprazole, blonanserin, and paliperidone) in patients with schizophrenia aged 20 years or over who required antipsychotic medication or switching of the current medication to others for reasons such as lack of efficacy and intolerability. The primary endpoint is treatment discontinuation rate for any causes. The secondary endpoints include remission rate, improvement of social activity, alleviation, aggravation or recurrence of psychiatric symptoms, and safety. The target number of subjects was set at 300. DISCUSSION: Because this study is expected to yield evidence regarding the selection of antipsychotics for facilitating the recovery of social activity in patients with schizophrenia, it is considered highly valuable to perform this effectiveness study under ordinary healthcare setting in Japan. TRIAL REGISTRATION: UMIN Clinical Trials Registry 000007942.
  • Tetsufumi Kanazawa, Masashi Ikeda, Stephen J Glatt, Atsushi Tsutsumi, Hiroki Kikuyama, Yoshiya Kawamura, Nao Nishida, Taku Miyagawa, Ryota Hashimoto, Masatoshi Takeda, Tsukasa Sasaki, Katsushi Tokunaga, Jun Koh, Nakao Iwata, Hiroshi Yoneda
    American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics 162B(7) 679-86 2013年10月  査読有り
    Atypical psychosis with a periodic course of exacerbation and features of major psychiatric disorders [schizophrenia (SZ) and bipolar disorder (BD)] has a long history in clinical psychiatry in Japan. Based upon the new criteria of atypical psychosis, a Genome-Wide Association Study (GWAS) was conducted to identify the risk gene or variants. The relationships between atypical psychosis, SZ and BD were then assessed using independent GWAS data. Forty-seven patients with solid criteria of atypical psychosis and 882 normal controls (NCs) were scanned using an Affymetrics 6.0 chip. GWAS SZ data (560 SZ cases and 548 NCs) and GWAS BD (107 cases with BD type 1 and 107 NCs) were compared using gene-based analysis. The most significant SNPs were detected around the CHN2/CPVL genes (rs245914, P = 1.6 × 10(-7)) , COL21A1 gene (rs12196860, P = 2.45 × 10(-7) ), and PYGL/TRIM9 genes (rs1959536, P = 7.73 × 10(-7) ), although none of the single-nucleotide polymorphisms exhibited genome-wide significance (P = 5 × 10(-8) ). One of the highest peaks was detected on the major histocompatibility complex region, where large SZ GWASs have previously disclosed an association. The gene-based analysis suggested significant enrichment between SZ and atypical psychosis (P = 0.01), but not BD. This study provides clues about the types of patient whose diagnosis lies between SZ and BD. Studies with larger samples are required to determine the causal variant.
  • Shabeesh Balan, Kazuo Yamada, Yoshimi Iwayama, Tomoko Toyota, Tetsuo Ohnishi, Motoko Maekawa, Manabu Toyoshima, Yasuhide Iwata, Katsuaki Suzuki, Mitsuru Kikuchi, Hiroshi Ujike, Toshiya Inada, Hiroshi Kunugi, Norio Ozaki, Nakao Iwata, Shinichiro Nanko, Tadafumi Kato, Takeo Yoshikawa
    Gene 526(2) 246-50 2013年9月10日  査読有り
    The early growth response gene 2 (EGR2) has been recently reported to be associated with bipolar disorder in the Korean population. However replication studies in independent cohorts of same and different ethnicities are essential for establishing the credibility of a genotype-phenotype association. With this notion, in the present study we have performed a replication study of the reported association of SNPs in EGR2 in a case-control study comprising of 867 unrelated Japanese bipolar disorder patients and 895 age-, sex- and ethnicity-matched controls. Results showed no significant differences in allele and genotype frequencies of EGR2 SNPs between bipolar disorder patients and controls and also in a sex-stratified genetic analysis. The haplotype and meta-analyses also showed no significant association with bipolar disorder. In conclusion, this is the first replication study of the previously reported association of EGR2 with bipolar disorder in a larger sample set and the results showed that the EGR2 gene is unlikely to contribute to the susceptibility of bipolar disorder in a Japanese cohort.
  • Masashi Ikeda, Yuko Okahisa, Branko Aleksic, Mujun Won, Naoki Kondo, Nobuya Naruse, Kumi Aoyama-Uehara, Ichiro Sora, Masaomi Iyo, Ryota Hashimoto, Yoshiya Kawamura, Nao Nishida, Taku Miyagawa, Masatoshi Takeda, Tsukasa Sasaki, Katsushi Tokunaga, Norio Ozaki, Hiroshi Ujike, Nakao Iwata
    Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology 38(10) 1864-70 2013年9月  査読有り
    Methamphetamine (METH) use can provoke psychotic reactions requiring immediate treatment, namely METH-induced psychosis. Although the distinction between METH-induced and primary psychosis is important for understanding their clinical courses, we do not have clear diagnostic procedure by their symptoms. Not only are there similarities between the clinical features of METH-induced psychosis and schizophrenia (SCZ), but there is also epidemiological evidence of a shared genetic risk between 'METH-related' disorders and SCZ, which makes the differentiation of these two conditions difficult. In this study, we conducted a genome-wide association study (GWAS) targeting METH-dependent patients. The METH sample group, used in the METH-dependence GWAS, included 236 METH-dependent patients and 864 healthy controls. We also included a 'within-case' comparison between 194 METH-induced psychosis patients and 42 METH-dependent patients without psychosis in a METH-induced psychosis GWAS. To investigate the shared genetic components between METH dependence, METH-induced psychosis, and SCZ, data from our previous SCZ GWAS (total N=1108) were re-analyzed. In the SNP-based analysis, none of the SNPs showed genome-wide significance in either data set. By performing a polygenic component analysis, however, we found that a large number of 'risk' alleles for METH-induced psychosis are over-represented in individuals with SCZ (Pbest=0.0090). Conversely, we did not detect enrichment either between METH dependence and METH-induced psychosis or between METH dependence and SCZ. The results support previous epidemiological and neurobiological evidence for a relationship between METH-induced psychosis and SCZ. These also suggest that the overlap between genes scored as positive in these data sets can have higher probability as susceptibility genes for psychosis.
  • Taro Kishi, Nakao Iwata
    Journal of psychiatric research 47(9) 1143-9 2013年9月  査読有り
    BACKGROUND: We examined whether N-methyl d-aspartate (NMDA) receptor antagonists as adjunctive therapy have therapeutic potential for schizophrenia treatment. METHOD: Systematic review of PubMed, Cochrane Library, PsycINFO and Google Scholar up until October 2012 and meta-analysis of randomized placebo-controlled trials were performed. Risk ratio (RR), 95% confidence intervals (CI), numbers-needed-to-harm (NNH), and standardized mean difference (SMD) were calculated. RESULTS: Results were across 8 studies and 406 patients (85.5% schizophrenia related disorder and 14.5% bipolar disorder) were included (amantadine: 5 trials and 220 patients, memantine: 3 trials and 186 patients). NMDA receptor antagonists (NMDAR-ANTs) as adjunctive therapy were not superior to placebo in overall (SMD = -0.25, CI = -0.72, 0.23, p = 0.31, N = 6, n = 347), positive symptoms (SMD = -0.20, CI = -0.70, 0.31, p = 0.44, N = 4, n = 205), and negative symptoms (SMD = -0.69, CI = -1.65, 0.27, p = 0.16, N = 4, n = 205), and Clinical Global Impression Severity scale (SMD = -0.27, CI = -1.20, 0.65, p = 0.56, N = 3, n = 177). There was also no significant difference in discontinuation rate between NMDAR-ANTs and placebo treatments (all cause: RR = 1.23, CI = 0.89-1.70, p = 0.20, N = 8, n = 396, side effects: RR = 1.86, CI = 0.84-4.13, p = 0.13, N = 6, n = 359, inefficacy/worsening psychosis: RR = 0.70, CI = 0.20-2.38, p = 0.56, N = 7, n = 380). However, memantine was favorable compared with placebo in Mini-Mental State Examination in schizophrenia (SMD = -0.77, CI = -1.27, -0.28, p = 0.002, N = 3, n = 71). While NMDAR-ANTs caused weight loss compared with placebo (SMD = -0.42, CI = -0.73, -0.11, p = 0.008, N = 3, n = 165), amantadine caused more frequent insomnia than placebo (RR = 3.83, CI = 1.41-10.38, p = 0.008, NNH = 9, p = 0.002, N = 2, n = 147). CONCLUSION: Our results indicate that NMDAR-ANTs as adjunctive therapy may improve cognitive function in patients with schizophrenia. Because the included studies were small, a replication study using larger samples is needed.
  • Taro Kishi, Nakao Iwata
    CNS drugs 27(9) 731-41 2013年9月  査読有り
    BACKGROUND: Perospirone is a second-generation antipsychotic (SGA) used only in Japan, and acts as a serotonin (5-HT)1A receptor partial agonist, 5-HT2A receptor inverse agonist, and dopamine (D)₂, D₄, and α₁-adrenergic receptor antagonist. To our knowledge, no meta-analysis addressing the efficacy and effectiveness of perospirone in schizophrenia has been published to date. OBJECTIVE: The aim of the study was to identify the characteristics of perospirone by assessing the efficacy, discontinuation rate, and side effects of perospirone versus other antipsychotics in the treatment of patients with schizophrenia. METHODS: Using information obtained from the PubMed, PsycINFO, Google Scholar and Cochrane Library databases without language restrictions published up to 10 June 2013, we conducted a systematic review and meta-analysis of patient data from randomized controlled trials comparing perospirone with other antipsychotic medications. Risk ratio (RR), standardized mean difference (SMD) and 95% confidence intervals were calculated. All studies used the Positive and Negative Syndrome Scale (PANSS) for the evaluation of the schizophrenia psychopathology. RESULTS: The search in PubMed, Cochrane Library databases, Google Scholar and PsycINFO yielded 69 hits. We included three studies in the current meta-analysis and excluded 66 studies based on title, abstract, and full text review. Moreover, two additional studies were identified from a review article. Across the five studies (mean duration 9.6 weeks), 562 adult patients with schizophrenia were randomized to perospirone (n = 256), olanzapine (n = 20), quetiapine (n = 28), risperidone (n = 53), aripiprazole (n = 49), haloperidol (n = 75), or mosapramine (n = 81). Perospirone was not different from other pooled antipsychotics regarding reduction in PANSS negative (SMD = 0.38, p = 0.09) and general (SMD = 0.28, p = 0.06) subscale scores, and discontinuation due to any cause (RR = 1.03, p = 0.83), inefficacy (RR = 0.99, p = 0.98) and side effects (RR = 0.72, p = 0.25). However, perospirone was inferior to other pooled antipsychotics in the reduction of PANSS total scores (SMD = 0.36, p = 0.04) and positive subscale scores (SMD = 0.34, p = 0.03). Moreover, excluding the comparison of perospirone with the first-generation antipsychotic (haloperidol), perospirone was inferior to other pooled SGAs in the reduction of PANSS total scores (SMD = 0.46, p = 0.02), positive (SMD = 0.42, p = 0.03), negative (SMD = 0.52, p = 0.02) and general subscale scores (SMD = 0.37, p = 0.03). However, perospirone was superior to haloperidol in the reduction of PANSS negative subscale scores (SMD = -0.41, p = 0.01). Perospirone also had lower scores related to extrapyramidal symptoms than other pooled antipsychotics (SMD = -0.30, p = 0.01). CONCLUSIONS: Our results suggest that although perospirone seems to be a well tolerated treatment, perospirone does not reduce PANSS score as much as other SGAs.
  • Masaomi Furukawa, Mamoru Tochigi, Takeshi Otowa, Tadao Arinami, Toshiya Inada, Hiroshi Ujike, Yuichiro Watanabe, Nakao Iwata, Masanari Itokawa, Hiroshi Kunugi, Ryota Hashimoto, Norio Ozaki, Chihiro Kakiuchi, Kiyoto Kasai, Tsukasa Sasaki
    Psychiatric genetics 23(4) 179-80 2013年8月  査読有り
  • Kosei Esaki, Kenji Kondo, Masakazu Hatano, Takeo Saito, Taro Kishi, Wakako Umene-Nakano, Reiji Yoshimura, Jun Nakamura, Norio Ozaki, Masashi Ikeda, Nakao Iwata
    Journal of human genetics 58(8) 568-9 2013年8月  査読有り
  • Sasayama D, Hiraishi A, Tatsumi M, Kamijima K, Ikeda M, Umene-Nakano W, Yoshimura R, Nakamura J, Iwata N, Kunugi H
    The pharmacogenomics journal 13(4) 354-358 2013年8月  査読有り
  • Taro Kishi, Herbert Y Meltzer, Nakao Iwata
    The international journal of neuropsychopharmacology 16(6) 1259-66 2013年7月  査読有り
    The aim of the study was to evaluate the evidence that serotonin1A (5-HT1A) receptor partial agonists of the azapirone class, which are not antipsychotic, have benefits for adjunctive treatment of overall psychopathology, positive and negative symptoms for patients with schizophrenia. We carried out a systematic review of the literature available through PubMed, Cochrane Library, PsycINFO and Google Scholar during September 2012, followed by a meta-analysis of randomized placebo-controlled trials. Risk ratio (RR), 95% confidence intervals (CI) and standardized mean difference (s.m.d.) were calculated. Four studies, involving 163 patients with schizophrenia, met inclusion criteria: buspirone: three trials and 137 patients; tandospirone: one trial and 26 patients. As adjunctive therapy, 5-HT1A partial agonists were significantly superior to placebo for overall improvement in psychopathology (s.m.d. = -0.46, CI = -0.79 to -0.13, p = 0.006, N = 4, n = 149) and marginally more effective to improve positive symptoms (s.m.d. = -0.31, CI = -0.64 to 0.01, p = 0.06, N = 4, n = 149). However, 5-HT1A partial agonists were not more efficacious than placebo as adjunctive therapy for improving negative symptoms (s.m.d. = -0.09, CI = -0.60 to 0.42, p = 0.72, N = 4, n = 149). In addition, there was no significant difference in discontinuation rates between 5-HT1A partial agonists and placebo (all cause: RR = 0.98, CI = 0.49-1.98, p = 0.96, N = 4, n = 153, side-effects: RR = 1.96, CI = 0.54-7.19, p = 0.31, N = 4, n = 153). 5-HT1A partial agonists as adjunctive therapy improved overall psychopathology with a trend to improve positive symptoms in patients with schizophrenia. Because the number of studies was small, additional controlled clinical trials with larger numbers of patients are indicated.
  • Motoshi Asano, Kosei Esaki, Aya Wakamatsu, Tomoko Kitajima, Tomohiro Narita, Hiroshi Naitoh, Norio Ozaki, Nakao Iwata
    Psychiatry and clinical neurosciences 67(5) 340-4 2013年7月  査読有り
    AIMS: The purpose of this study was to predict the outcome of cognitive behavior therapy (CBT) by trainees for major depressive disorder (MDD) based on the Parental Bonding Instrument (PBI). The hypothesis was that the higher level of care and/or lower level of overprotection score would predict a favorable outcome of CBT by trainees. METHODS: The subjects were all outpatients with MDD treated with CBT as a training case. All the subjects were asked to fill out the Japanese version of the PBI before commencing the course of psychotherapy. The difference between the first and the last Beck Depression Inventory (BDI) score was used to represent the improvement of the intensity of depression by CBT. In order to predict improvement (the difference of the BDI scores) as the objective variable, multiple regression analysis was performed using maternal overprotection score and baseline BDI score as the explanatory variables. RESULTS: The multiple regression model was significant (P = 0.0026) and partial regression coefficient for the maternal overprotection score and the baseline BDI was -0.73 (P = 0.0046) and 0.88 (P = 0.0092), respectively. Therefore, when a patient's maternal overprotection score of the PBI was lower, a better outcome of CBT was expected. CONCLUSION: The hypothesis was partially supported. This result would be useful in determining indications for CBT by trainees for patients with MDD.
  • Hiroki Shibata, Ken Yamamoto, Zhu Sun, Akira Oka, Hidetoshi Inoko, Tadao Arinami, Toshiya Inada, Hiroshi Ujike, Masanari Itokawa, Mamoru Tochigi, Yuichiro Watanabe, Toshiyuki Someya, Hiroshi Kunugi, Tatsuyo Suzuki, Nakao Iwata, Norio Ozaki, Yasuyuki Fukumaki
    Psychiatric genetics 23(3) 117-23 2013年6月  査読有り
    OBJECTIVES: To search for schizophrenia susceptibility loci, we carried out a case-control study using 28601 microsatellite markers distributed across the entire genome. MATERIALS AND METHODS: To control the highly multiple testing, we designed three sequential steps of screening using three independent sets of pooled samples, followed by the confirmatory step using an independent sample set (>2200 case-control pairs). RESULTS: The first screening using pooled samples of 157 case-control pairs showed 2966 markers to be significantly associated with the disorder (P<0.05). After the second and the third screening steps using pooled samples of 150 pairs each, 374 markers remained significantly associated with the disorder. We individually genotyped all screening samples using a total of 1536 tag single nucleotide polymorphisms (SNPs) located in the vicinity of ~200 kb from the 59 positive microsatellite markers. Of the 167 SNPs that replicated the significance, we selected 31 SNPs on the basis of the levels of P values for the confirmatory association test using an independent-sample set. The best association signal was observed in rs13404754, located in the upstream region of SLC23A3. We genotyped six additional SNPs in the vicinity of rs13404754. Significant associations were observed in rs13404754, rs6436122, and rs1043160 in the cumulative samples (2617 cases and 2698 controls) (P=0.005, 0.035, and 0.011, respectively). These SNPs are located in the linkage disequilibrium block of 20 kb in size containing SLC23A3, CNPPD1, and FAM134A genes. CONCLUSION: Genome-wide association study using microsatellite markers suggested SLC23A3, CNPPD1, and FAM134A genes as candidates for schizophrenia susceptibility in the Japanese population.
  • Ryota Hashimoto, Masashi Ikeda, Kazutaka Ohi, Yuka Yasuda, Hidenaga Yamamori, Motoyuki Fukumoto, Satomi Umeda-Yano, Dwight Dickinson, Branko Aleksic, Masao Iwase, Hiroaki Kazui, Norio Ozaki, Daniel R Weinberger, Nakao Iwata, Masatoshi Takeda
    The American journal of psychiatry 170(6) 683-4 2013年6月  査読有り
  • Taro Kishi, Kiyoshi Fujita, Osamu Furukawa, Tatsuyo Suzuki, Masatsugu Moriwaki, Mari Nitta, Miho Hattori, Tomoko Tsunoka, Raja Chekuri, John M Kane, Christoph U Correll, Nakao Iwata
    Asian journal of psychiatry 6(3) 200-7 2013年6月  査読有り
    Japan approved clozapine for treatment-resistant schizophrenia in June 2009. The aim of this study was to evaluate clozapine's efficacy and tolerability in Japanese patients. A twelve-week, single-arm clinical trial of clozapine in treatment-resistant schizophrenia inpatients, was conducted under real-world conditions using raters masked for type of antipsychotic. Thirty-eight patients were recruited, with 33 (86.8%) completing the trial. At week 12, clozapine was associated with significant improvement in the Positive and Negative Syndrome Scale (PANSS) total (p < 0.0001), PANSS positive (p < 0.0001), negative (p = 0.0055) and general subscale scores (p < 0.0001). Significant improvements occurred in all PANSS scores by week 4, the first post-baseline psychopathology rating. Altogether, 50.0% of patients showed ≥20% reduction in PANSS total score, 20.6% had ≥30% reduction and 14.7% had >40% reduction. Eighteen patients (47.4%) were discharged before week 12. However, all patients experienced ≥1 adverse event. Two of 38 patients (5.2%) dropped out due to moderate leucopenia and one of them developed agranulocytosis after stopping clozapine. However, both patients recovered. Eight adverse events (hypersalivation, fatigue, sedation, constipation, insomnia, nausea/vomiting, chest pain and leucopenia) were observed in 34-79% of patients. These findings suggest that clozapine is beneficial in Japanese treatment-resistant schizophrenia patients. However, attention should be paid to patients' adverse events.
  • 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 28(3) 220-9 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 Fagerström 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.
  • Koichi Furuhashi, Nakao Iwata
    Nihon rinsho. Japanese journal of clinical medicine 71(4) 635-40 2013年4月  査読有り
    Schizophrenia is chronically progressed disease with a functional decline and adequate treatment is needed for respective clinical stages. Duration of psychosis before treatment is called DUP (duration of untreated psychosis) and may be an important predictor of outcome. Furthermore, the early phase of schizophrenia including DUP is considered a critical period, in which long-term outcome is predictable. Therefore, that shows the importance of early detection and intervention for schizophrenia and relapse prevention during a critical period. The atypical antipsychotics now play the leading role in pharmacotherapy of schizophrenia. They clearly decrease adverse effects, and may prevent the relapse and improve long-term outcome. However, better pharmacotherapy needs the viewpoint of adherence and we do not have to remember the importance of psychosocial therapy.
  • 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.
  • Saurav Guha, Elliott Rees, Ariel Darvasi, Dobril Ivanov, Masashi Ikeda, Sarah E Bergen, Patrik K Magnusson, Paul Cormican, Derek Morris, Michael Gill, Sven Cichon, Jeffrey A Rosenfeld, Annette Lee, Peter K Gregersen, John M Kane, Anil K Malhotra, Marcella Rietschel, Markus M Nöthen, Franziska Degenhardt, Lutz Priebe, René Breuer, Jana Strohmaier, Douglas M Ruderfer, Jennifer L Moran, Kimberly D Chambert, Alan R Sanders, Jianxin Shi, Kenneth Kendler, Brien Riley, Tony O'Neill, Dermot Walsh, Dheeraj Malhotra, Aiden Corvin, Shaun Purcell, Pamela Sklar, Nakao Iwata, Christina M Hultman, Patrick F Sullivan, Jonathan Sebat, Shane McCarthy, Pablo V Gejman, Douglas F Levinson, Michael J Owen, Michael C O'Donovan, Todd Lencz, George Kirov
    JAMA psychiatry 70(3) 253-60 2013年3月  査読有り
    CONTEXT: Large genomic copy number variations have been implicated as strong risk factors for schizophrenia. However, the rarity of these events has created challenges for the identification of further pathogenic loci, and extremely large samples are required to provide convincing replication. OBJECTIVE: To detect novel copy number variations that increase the susceptibility to schizophrenia by using 2 ethnically homogeneous discovery cohorts and replication in large samples. DESIGN: Genetic association study of microarray data. SETTING: Samples of DNA were collected at 9 sites from different countries. PARTICIPANTS: Two discovery cohorts consisted of 790 cases with schizophrenia and schizoaffective disorder and 1347 controls of Ashkenazi Jewish descent and 662 parent-offspring trios from Bulgaria, of which the offspring had schizophrenia or schizoaffective disorder. Replication data sets consisted of 12,398 cases and 17,945 controls. MAIN OUTCOME MEASURES: Statistically increased rate of specific copy number variations in cases vs controls. RESULTS: One novel locus was implicated: a deletion at distal 16p11.2, which does not overlap the proximal 16p11.2 locus previously reported in schizophrenia and autism. Deletions at this locus were found in 13 of 13,850 cases (0.094%) and 3 of 19,954 controls (0.015%) (odds ratio, 6.25 [95% CI, 1.78-21.93]; P = .001, Fisher exact test). CONCLUSIONS: Deletions at distal 16p11.2 have been previously implicated in developmental delay and obesity. The region contains 9 genes, several of which are implicated in neurological diseases, regulation of body weight, and glucose homeostasis. A telomeric extension of the deletion, observed in about half the cases but no controls, potentially implicates an additional 8 genes. Our findings add a new locus to the list of copy number variations that increase the risk for development of schizophrenia.
  • 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) 105-18 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.
  • Taro Kishi, Yuki Matsuda, Hiroshi Nakamura, Nakao Iwata
    Journal of psychiatric research 47(2) 149-54 2013年2月  査読有り
    BACKGROUND: There is uncertainty about the efficacy and tolerability of blonanserin in schizophrenia. METHOD: PubMed, the Cochrane Library databases, PsycINFO, and Google Scholar were searched up to September 2012. A systematic review and meta-analysis of individual patient data from randomized, controlled trials comparing blonanserin with other antipsychotics were conducted. The risk ratio (RR), 95% confidence intervals (CI), numbers-needed-to-harm (NNH), and weighted mean difference (WMD) were calculated. RESULTS: Four studies (total n = 1080) were identified (vs. risperidone studies [n = 508], vs. haloperidol studies [n = 572]). Comparing blonanserin with other pooled antipsychotics, there were no significant differences in the Positive and Negative Syndrome Scale (PANSS) total score (p = 0.75), PANSS positive (p = 0.41), PANSS negative (p = 0.09), and PANSS general psychopathology subscale scores (p = 0.96), and response rate (p = 0.72). However, blonanserin showed greater efficacy in PANSS negative subscale scores compared with haloperidol (WMD = -1.29, CI = -2.29 to -0.30, p = 0.01, I(2) = 0%). No significant differences were found in discontinuation rates between blonanserin and other pooled antipsychotics (due to any cause: p = 0.29, inefficacy: p = 0.32, adverse events: p = 0.56). Blonanserin had a 0.31 lower risk of hyperprolactinemia than the other pooled antipsychotics (CI = 0.20-0.49, NNH = not significant). While dizziness (RR = 0.47, CI = 0.23-0.93, NNH = not significant) and akathisia (RR = 0.54, CI = 0.32-0.90, NNH = 7) occurred significantly less often with blonanserin than with haloperidol, blonanserin had a 1.62 higher risk of akathisia than risperidone (CI = 1.18-2.22, NNH = 8) [corrected]. CONCLUSION: Our results suggest that although blonanserin has a more beneficial effect on negative symptoms than haloperidol, there was a significant difference in the adverse events profile between blonanserin and other antipsychotics.
  • Taro Kishi, Tatsuyo Suzuki, Hirotaka Sekiguchi, Masatsugu Moriwaki, Akiko Okuda, Takahiro Mekata, Miho Hattori, Tomoko Tsunoka, Raja Chekuri, Giovanna M Musso, Kiyoshi Fujita, Nakao Iwata
    Asian journal of psychiatry 6(1) 86-7 2013年2月  査読有り
  • Branko Aleksic, Itaru Kushima, Tamae Ohye, Masashi Ikeda, Shohko Kunimoto, Yukako Nakamura, Akira Yoshimi, Takayoshi Koide, Shuji Iritani, Hiroki Kurahashi, Nakao Iwata, Norio Ozaki
    Scientific reports 3 2587-2587 2013年  査読有り
    Using a very high-resolution oligonucleotide array for copy number variant (CNV) screening of samples comprising schizophrenic patients, we detected a novel CNV within the critical region (NCBI36/hg18, Chr7: 158,630,410-158,719,410) previously shown to be associated with schizophrenia. We investigated the association between the novel CNV identified in the current study and schizophrenia. Three independent samples were used: (1) Screening set, 300 Japanese schizophrenic patients (53.28 ± 14.66 years); (2) Confirmation set, 531 schizophrenic patients (46.03 ± 12.15 years); and (3) 711 healthy controls (47.12 ± 11.03 years). All subjects enrolled in the study were Japanese. Chromosomal position was determined using fluorescence in situ hybridization. We identified a novel duplication within the region associated with schizophrenia identified on 7q36.3 that is adjacent to VIPR2 and is not associated with schizophrenia. In the Japanese population, the 35-kb region that harbors the common, novel CNV should be excluded from the region associated with schizophrenia on 7q36.3.
  • Todd Lencz, Saurav Guha, Chunyu Liu, Jeffrey Rosenfeld, Semanti Mukherjee, Pamela DeRosse, Majnu John, Lijun Cheng, Chunling Zhang, Judith A Badner, Masashi Ikeda, Nakao Iwata, Sven Cichon, Marcella Rietschel, Markus M Nöthen, A T A Cheng, Colin Hodgkinson, Qiaoping Yuan, John M Kane, Annette T Lee, Anne Pisanté, Peter K Gregersen, Itsik Pe'er, Anil K Malhotra, David Goldman, Ariel Darvasi
    Nature communications 4 2739-2739 2013年  査読有り
    Schizophrenia and bipolar disorder are major psychiatric disorders with high heritability and overlapping genetic variance. Here we perform a genome-wide association study in an ethnically homogeneous cohort of 904 schizophrenia cases and 1,640 controls drawn from the Ashkenazi Jewish population. We identify a novel genome-wide significant risk locus at chromosome 4q26, demonstrating the potential advantages of this founder population for gene discovery. The top single-nucleotide polymorphism (SNP; rs11098403) demonstrates consistent effects across 11 replication and extension cohorts, totalling 23, 191 samples across multiple ethnicities, regardless of diagnosis (schizophrenia or bipolar disorder), resulting in Pmeta=9.49 × 10(-12) (odds ratio (OR)=1.13, 95% confidence interval (CI): 1.08-1.17) across both disorders and Pmeta=2.67 × 10(-8) (OR=1.15, 95% CI: 1.08-1.21) for schizophrenia alone. In addition, this intergenic SNP significantly predicts postmortem cerebellar gene expression of NDST3, which encodes an enzyme critical to heparan sulphate metabolism. Heparan sulphate binding is critical to neurite outgrowth, axon formation and synaptic processes thought to be aberrant in these disorders.
  • Jiewei Liu, Shusuke Numata, Masashi Ikeda, Yuichiro Watanabe, Xue-Bin Zheng, Xiongjian Luo, Makoto Kinoshita, Ayako Nunokawa, Toshiyuki Someya, Tetsuro Ohmori, Jin-Xin Bei, Siow-Ann Chong, Jimmy Lee, Zhiqiang Li, Jianjun Liu, Nakao Iwata, Yongyong Shi, Ming Li, Bing Su
    PloS one 8(11) e80696 2013年  査読有り
    Recent genetic analyses have implicated several candidate susceptibility variants for schizophrenia. The single nucleotide polymorphism (SNP) rs7294919 is likely a schizophrenia-susceptibility variant according to its significant association with hippocampal volume, hippocampus function, and cognitive performance as well as the nominal association with schizophrenia. However, all previous analyses were conducted only in Europeans, and whether rs7294919 is associated with schizophrenia in other populations are yet to be tested. Here, we conducted a case-control analysis of rs7294919 with schizophrenia in six independent Chinese (N = 3) and Japanese (N = 3) samples, including a total of 7,352 cases and 10,824 controls. The results of our association analysis were not able to confirm the association of rs7294919 with schizophrenia (p = 0.51 in total samples, odds ratio = 1.02 for allele[C]). The absence of rs7294919's association in Chinese and Japanese suggest a potential genetic heterogeneity in the susceptibility of schizophrenia on this locus and also demonstrate the difficulties in replicating associations of schizophrenia across different ethnic populations.
  • Iwata N, Tourian KA, Hwang E, Mele L, Vialet C
    Journal of psychiatric practice 19(1) 5-14 2013年1月  査読有り
  • Yuki Matsuda, Taro Kishi, Hiroto Shibayama, Nakao Iwata
    Human psychopharmacology 28(1) 80-6 2013年1月  査読有り
    OBJECTIVES: There is currently no meta-analysis of the efficacy and tolerability of Yokukansan in the treatment of behavioral and psychological symptoms of dementia. METHOD: We used information obtained from the PubMed and Cochrane Library databases until October 2012. We conducted a systematic review and meta-analysis of individual patient data from randomized controlled trials comparing Yokukansan with usual care (UC, i.e., controls). Standardized mean difference and weighted mean difference were calculated. All studies used the Neuropsychiatric Inventory (NPI) for the evaluation of behavioral and psychological symptoms of dementia. RESULTS: Four relevant studies (total n = 236) were identified. Yokukansan was superior to UC in the reduction of total NPI scores (p = 0.0009, weighted mean difference = -7.20, I(2) = 0%). In addition, Yokukansan was more efficacious in reducing scores on the NPI subscale (delusions, hallucinations, and agitation/aggression) than UC (p < 0.00001-0.0009). Yokukansan treatment also improved activities of daily living scores compared with UC (p = 0.04, standardized mean difference = -0.32, I(2) = 0%). Mini-mental state examination scores did not differ between the Yokukansan and UC treatment groups. Yokukansan was not different from UC regarding discontinuation due to any cause. CONCLUSION: Our results suggest that Yokukansan has a beneficial effect on NPI and on ADL scores and that Yokukansan seems to be a well-tolerated treatment.
  • Kei Nagao, Taro Kishi, Masatsugu Moriwaki, Kiyoshi Fujita, Shigeki Hirano, Yoshio Yamanouchi, Toshihiko Funahashi, Nakao Iwata
    Neuropsychiatric disease and treatment 9 781-6 2013年  査読有り
    No studies have compared mirtazapine with duloxetine in patients with major depressive disorder (MDD). Fifty-six patients were nonrandomly assigned to a 4-week treatment with either 15 to 45 mg/day of mirtazapine (n = 22) or 20 to 60 mg/day of duloxetine (n = 34). The primary efficacy measurements were the Hamilton Rating Scale for Depression (HRSD) and the Montgomery-Åsberg Depression 6-point Rating Scale (MADRS) scores. The second efficacy measurements were the response and remission rates of treatment. Tolerability assessments were also performed. Fifty-six patients (43 male; age, 43.6 years) were recruited. There was no significant difference in the discontinuation rate between the mirtazapine and duloxetine treatment groups (P = 0.867). Both mirtazapine and duloxetine significantly improved the HRSD and MADRS scores from baseline (P < 0.0001-0.0004). While mirtazapine was superior to duloxetine in the reduction of HRSD scores (P = 0.0421), there was no significant change in MADRS scores in terms of between-group differences (P = 0.171). While more somnolence was observed with mirtazapine (P = 0.0399), more nausea was associated with duloxetine (P = 0.0089). No serious adverse events were observed for either antidepressant. Mirtazapine and duloxetine were safe and well-tolerated treatments for Japanese patients with MDD. Double-blind controlled studies are needed to further explore the efficacy and safety of mirtazapine and duloxetine in Japanese patients with MDD.
  • Kenji Kondo, Masashi Ikeda, Yusuke Kajio, Takeo Saito, Yoshimi Iwayama, Branko Aleksic, Kazuo Yamada, Tomoko Toyota, Eiji Hattori, Hiroshi Ujike, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Norio Ozaki, Nakao Iwata
    PloS one 8(8) e70964 2013年  査読有り
    BACKGROUND: Recent genome-wide association studies (GWASs) investigating bipolar disorder (BD) have detected a number of susceptibility genes. These studies have also provided novel insight into shared genetic components between BD and schizophrenia (SCZ), two major psychotic disorders. To examine the replication of the risk variants for BD and the pleiotropic effect of the variants associated with BD, we conducted a genetic association study of single nucleotide polymorphisms (SNPs) that were selected based upon previous BD GWASs, which targeted psychotic disorders (BD and SCZ) in the Japanese population. METHODS: Forty-eight SNPs were selected based upon previous GWASs. A two-stage analysis was conducted using first-set screening (for all SNPs: BD = 1,012, SCZ = 1,032 and control = 993) and second-set replication samples (for significant SNPs in the screening analysis: BD = 821, SCZ = 1,808 and control = 2,149). We assessed allelic association between BD, SCZ, psychosis (BD+SCZ) and the SNPs selected for the analysis. RESULTS: Eight SNPs revealed nominal association signals for all comparisons (Puncorrected<0.05). Among these SNPs, the top two SNPs (associated with psychosis: Pcorrected = 0.048 and 0.037 for rs2251219 and rs2709722, respectively) were further assessed in the second-set samples, and we replicated the signals from the initial screening analysis (associated with psychosis: Pcorrected = 0.0070 and 0.033 for rs2251219 and rs2709722, respectively). The meta-analysis between the current and previous GWAS results showed that rs2251219 in Polybromo1 (PBRM1) was significant on genome-wide association level (P = 5×10(-8)) only for BD (P = 9.4×10(-9)) and psychosis (P = 2.0×10(-10)). Although the association of rs2709722 in Sp8 transcription factor (SP8) was suggestive in the Asian population (P = 2.1×10(-7) for psychosis), this signal weakened when the samples size was increased by including data from a Caucasian population (P = 4.3×10(-3)). CONCLUSIONS: We found 3p21.1 (including PBRM1, strong linkage disequilibrium made it difficult to pinpoint the risk genes) and SP8 as risk loci for BD, SCZ and psychosis. Further replication studies will be required for conclusive results.
  • Yueren Zhao, Taro Kishi, Nakao Iwata, Manabu Ikeda
    Neuropsychiatric disease and treatment 9 1655-9 2013年  査読有り
    A recent meta-analysis showed that long-acting injectable (LAI) antipsychotics were not superior to oral antipsychotics for preventing relapse in patients with schizophrenia. We therefore designed a treatment strategy combining risperidone LAI and COMPASS (COMprehensive Psycho-educational Approach and Scheme Set), an original psychoeducational program supporting treatment with risperidone LAI and evaluating subjective treatment satisfaction, transition of symptoms, and effectiveness in preventing symptomatic relapse. The aim of this study was to examine whether addition of COMPASS to risperidone LAI was more effective in preventing relapse in schizophrenia patients than risperidone LAI alone, with the latter group consisting of patients enrolled in a Phase III trial of risperidone LAI in Japan. Patients were followed up for 6 months, with COMPASS continuously implemented from the transition to the observation phase. The primary efficacy measurements were relapse rate (rates of rehospitalization and discontinuation due to inefficacy). Secondary efficacy measurements were the Brief Psychiatric Rating Scale (BPRS) and Global Assessment of Functioning (GAF) scores. Of the 96 patients originally enrolled, 19 (19.8%) were discontinued from all causes. During the 6-month study period, ten of the 96 patients (10.4%) relapsed, compared with a 12.2% relapse rate in patients enrolled in a Phase III trial of risperidone LAI in Japan. Patients showed significant improvements in BPRS total scores (P = 0.0031), BPRS positive (P = 0.0451), BRPS negative (P < 0.0001), and general subscale scores (P = 0.0031), and GAF (P < 0.0001) from baseline to 6 months. In conclusion, the lower relapse rate observed in patients treated with COMPASS plus risperidone LAI than in patients treated with risperidone LAI alone suggests that COMPASS may have benefits in the treatment of schizophrenia, indicating a need for randomized, controlled trials in larger numbers of patients.
  • Ikeda M, Aleksic B, Yamada K, Iwayama-Shigeno Y, Matsuo K, Numata S, Watanabe Y, Ohnuma T, Kaneko T, Fukuo Y, Okochi T, Toyota T, Hattori E, Shimodera S, Itakura M, Nunokawa A, Shibata N, Tanaka H, Yoneda H, Arai H, Someya T, Ohmori T, Yoshikawa T, Ozaki N, Iwata N
    Molecular Psychiatry 18(6) 636-638 2013年  査読有り
  • Taro Kishi, Hiroshi Ichinose, Reiji Yoshimura, Yasuhisa Fukuo, Tsuyoshi Kitajima, Toshiya Inada, Hiroshi Kunugi, Tadafumi Kato, Takeo Yoshikawa, Hiroshi Ujike, Giovanna M Musso, Wakako Umene-Nakano, Jun Nakamura, Norio Ozaki, Nakao Iwata
    Journal of affective disorders 142(1-3) 315-22 2012年12月15日  査読有り
    BACKGROUND: Tetrahydrobiopterin (BH4) plays an important role in the biosynthesis of serotonin, melatonin and catecholamines, all of which are implicated in the pathophysiology of mood disorders (MDs), including major depressive disorder (MDD) and bipolar disorder (BP). Production of BH4 is regulated by GTP cyclohydrolase transcription and activity. Thus, we considered the GTP cyclohydrolase gene (GCH1) to be a good candidate gene in the pathophysiology of MDs and of the serotonin selective reuptake inhibitors (SSRIs) response in MDD, and conducted a case-control study utilizing three SNPs (rs8007267, rs3783641 and rs841) and moderate sample sizes (405 MDD patients, including 262 patients treated by SSRIs, 1022 BP patients and 1805 controls). METHOD: A multiple logistic regression analysis was carried out to compare the frequencies of each SNP genotype for the target phenotype across patients and controls in several genetic models, while adjusting for possible confounding factors. A clinical response was defined as a decrease of more than 50% from the baseline score on the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D) within 8 weeks, and clinical remission as a SIGH-D score of less than 7 at 8 weeks. RESULT: No associations between three SNPs in GCH1 and MDD or BP were observed; however, GCH1 was associated with SSRI therapeutic response in MDD in all the marker's haplotype analysis (Global P value=0.0379). CONCLUSIONS: Results suggest that GCH1 may predict response to SSRI in MDD in the Japanese population. Nevertheless, a replication study using larger samples may be required for conclusive results, since our sample size was small.
  • Reiji Yoshimura, Taro Kishi, Hikaru Hori, Atsuko Ikenouchi-Sugita, Asuka Katsuki, Wakako Umene-Nakano, Nakao Iwata, Jun Nakamura
    Progress in neuro-psychopharmacology & biological psychiatry 39(2) 355-7 2012年12月3日  査読有り
    OBJECTIVE: Only two-thirds of depressive patients respond to antidepressant treatment. In recent years, addition of an atypical antipsychotic drug to ongoing treatment with an antidepressant has been considered effective and well-tolerated. In the present study, we compared the efficacy between paroxetine and sertraline augmented with aripiprazole in patients with refractory major depression. SUBJECTS AND METHODS: Twenty-four patients who met the DSM-IV criteria for major depressive disorder who did not at least two different classes of antidepressants were enrolled in the study. Nine were male and thirteen were female, and their ages ranged from 28 to 66 (mean±SD=39±12) years. Patients were prescribed paroxetine (n=11) or sertraline (n=13) for 4weeks. Then, those whose scores on the 17-item Hamilton Rating Scale for Depression (HAMD17) decreased below 50% received adjunctive therapy of aripiprazole for 4weeks. RESULTS: Although the use of either combination treatment decreased the HAMD17 scores compared to the respective monotherapy, there was no significant difference in HAMD17 scores between the paroxetine plus aripiprazole group and sertraline plus aripiprazole group. CONCLUSION: Aripiprazole augmentation therapy with paroxetine or sertraline was equally effective and tolerated in patients with refractory major depressive order.

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