Methylation analysis for postpartum depression: a case control study.

BACKGROUND: Postpartum depression (PPD) is a major depressive disorder that occurs after childbirth. Objective diagnostic and predictive methods for PPD are important for early detection and appropriate intervention. DNA methylation has been recognized as a potential biomarker for major depressive disorder. In this study, we used methylation analysis and peripheral blood to search for biomarkers that could to lead to the development a predictive method for PPD. METHODS: Study participants included 36 pregnant women (18 cases and 18 controls determined after childbirth). Genome-wide DNA methylation profiles were obtained by analysis with an Infinium Human Methylation 450BeadChip. The association of DNA methylation status at each DNA methylation site with PPD was assessed using linear regression analysis. We also conducted functional enrichment analysis of PPD using The Database for Annotation, Visualization and Integrated Discovery 6.8 to explore enriched functional-related gene groups for PPD. RESULTS: In the analysis with postpartum depressed state as an independent variable, the difference in methylation frequency between the postpartum non-depressed group and the postpartum depressed group was small, and sites with genome-wide significant differences were not confirmed. After analysis by The Database for Annotation, Visualization and Integrated Discovery 6.8, we revealed four gene ontology terms, including axon guidance, related to postpartum depression. CONCLUSIONS: These findings may help with the development of an objective predictive method for PPD.

Issues on the diagnosis and etiopathogenesis of mood disorders: reconsidering DSM-5.

The authors present a narrative review from the diagnostic and nosologic viewpoints of mood disorders (bipolar and depressive ones) by revisiting the revision from the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, Text Revision to DSM-5, including the following: the separation of the bipolar and depressive sections; the addition of increased energy and continuation of symptoms to the hypo/manic criteria; the elimination of mixed episodes; the creation of new categories and specifiers ("other specified bipolar and related disorder", "disruptive mood dysregulation disorder", "with anxious distress", "with mixed features", "with peripartum onset"); the categorization of hypo/manic episodes during antidepressant treatment into bipolar disorder; the elimination of the "bereavement exclusion"; the ambiguous separation between bipolar I and II; the insufficient distinction between "other specified bipolar and related disorders" and major depressive disorder; the differentiation regarding borderline personality disorder; agitation; premenstrual dysphoric disorder; and society and psychiatry. Through this analysis, we point out both the achievements and limitations of DSM-5. In addition, to examine the future direction of psychiatry, we introduce our cohort study regarding maternal depression and an outline of the National Institute of Mental Health's Research Domain Criteria project in the US. Finally, we advocate the importance of elucidating etiopathogeneses by starting from or going beyond the DSM operational diagnostic system, which has shown great efficacy.

The coping process of Japanese parents who experience violence from adult children with schizophrenia.

With the acceleration of deinstitutionalization might increase families' chances of suffering violence by patients. This study clarified parents' coping processes with violence experienced from patients with schizophrenia. The grounded theory approach was used, and 26 parents were interviewed. We identified a four-stage coping process: (1) hope for treatment, (2) living with violence, (3) trying to solve violence, and (4) last solution for violence. This coping process had two illness-related characteristics: (1) a process of coping with two main stressful events (the illness and violence), and (2) the need for long-term appraisal of violence because of its unclear causes.

Violence Towards Family Caregivers by Their Relative with Schizophrenia in Japan.

There have been several violence-related deaths in Japan due to family violence by persons with severe mental illness against their caregivers. However, it is not often acknowledged that these violent acts are mainly directed at family members. This study aimed to clarify what acts of violence family caregivers experienced from their relative with schizophrenia, and how frequently these violent incidents occurred in their lifetime. We also examined caregivers' thoughts of death about themselves and their relatives, as well as their consultation efforts and escape from the violence perpetrated by their relative. Of the 277 caregivers, 87.7% had experienced psychological violence and 75.8% had experienced physical violence perpetrated by their relative. Of 210 caregivers who had experienced physical violence, 26.7% had thought of murder-suicide and 31.0% had wished for their relative's death. Family violence by persons with schizophrenia is not rare but a common occurrence in Japan and may have fatal consequences.

Relationship between maternal depression and bonding failure: A prospective cohort study of pregnant women.

AIM: Although the association between maternal depression and bonding failure during pregnancy and after delivery has been investigated, the causal relationships remain unclear. METHODS: A total of 751 women (mean [SD] age, 32.1 [4.4] years) completed the Mother-Infant Bonding Questionnaire and the Edinburgh Postnatal Depression Scale during early pregnancy before week 25 (T1), during late pregnancy around week 36 (T2), and at 5 days after delivery (T3). We created a structural regression model to clarify the relationships between depressive mood and bonding failure during pregnancy and at 5 days after delivery. The model was tested with structural equation modeling. RESULTS: Our non-recursive model fit the data well, and we found that: (i) during T2, bonding failure predicted depressive mood (P < 0.01, r = 0.23); (ii) at T3, bonding failure predicted depressive mood (P < 0.05, r = 0.31); (iii) during T1, depressive mood was correlated with bonding failure (P < 0.01, r = 0.45); (iv) depressive mood during T1 predicted depressive mood during T2 (P < 0.01, r = 0.58); (v) depressive mood during T2 predicted depressive mood at T3 (P < 0.01, r = 0.45); (vi) bonding failure during T1 predicted bonding failure during T2 (P < 0.01, r = 0.84); and (vii) bonding failure during T2 predicted bonding failure at T3 (P < 0.01, r = 0.44). The determinant coefficients of depressive mood and bonding failure at T3 were 0.41 and 0.28, respectively. CONCLUSION: Our large-scale cohort study indicates that bonding failure predicts depressive mood during pregnancy and 5 days after delivery. These findings suggest that protection and support for pregnant women with depressive mood and bonding failure may prevent both issues during pregnancy and the early stage after delivery.

Changes in Families' Caregiving Experiences through Involvement as Participants then Facilitators in a Family Peer-Education Program for Mental Disorders in Japan.

A family peer-education program for mental disorders was developed in Japan, similar to existing programs in the United States and Hong Kong. Families that serve as facilitators in such programs may enhance their caregiving processes and, thereby, their well-being. This study's aim was to describe how families' caregiving experiences change, beginning with the onset of a family member's mental illness, through their involvement in a family group or peer-education program as participants then facilitators. Thus, this study was conducted in a family peer-education program for mental disorders in Japan. Group interviews were conducted with 27 facilitators from seven program sites about their experiences before, during, and after becoming facilitators. Interview data were coded and categorized into five stages of caregiving processes: (1) withdrawing and suppressing negative experiences with difficulty and regret; (2) finding comfort through being listened to about negative experiences; (3) supporting participants' sharing as facilitators; (4) understanding and affirming oneself through repeated sharing of experiences; and (5) finding value and social roles in one's experiences. The third, fourth, and fifth stages were experienced by the facilitators. The value that the facilitators placed on their caregiving experiences changed from negative to positive, which participants regarded as helpful and supportive. We conclude that serving as facilitators may improve families' caregiving processes.

Validation and factor analysis of mother-infant bonding questionnaire in pregnant and postpartum women in Japan.

BACKGROUND: The Mother-Infant Bonding Questionnaire (MIBQ) has been widely used to assess maternal emotional involvement with infants. Although the reliability and validity of the MIBQ in the postpartum period has been confirmed, it remains unclear whether the MIBQ is appropriate to assess maternal bonding in both pregnancy and the postpartum period over time. Our study were aimed to 1) examine the reliability and validity of the MIBQ for clinical use among pregnant and postpartum women; and 2) examine the factor structure of the items, create subscales, and confirm the stability of the MIBQ in the pregnancy and postpartum periods. METHODS: Participants (n = 751, mean age 32.1 ± 4.4 years) completed the MIBQ and the Edinburgh Postnatal Depression Scale (EPDS) in early pregnancy (before week 25), in late pregnancy (around week 36), 5 days after delivery, and 1 month after delivery. We randomly divided participants into two sample sets. We conducted an exploratory factor analysis of the nine MIBQ items using data from one group of mothers (Group 1; n = 376) in all four periods. The factor structure derived from the exploratory factor analysis was confirmed by a confirmatory factor analysis in the second group (Group 2; n = 375) of mothers in all four periods. RESULTS: Exploratory factor analysis yielded two factors: Lack of Affection (LA) and Anger and Rejection (AR). Confirmatory factor analysis demonstrated that LA and AR factors existed for the MIBQ in all periods. Cronbach's alpha coefficients were 0.879 and 0.584, respectively. The scores for LA and AR were significantly correlated over the four time periods. Mothers with higher AR scores on the MIBQ at any of the four periods had higher scores on the EPDS. CONCLUSIONS: The MIBQ has two subscales regardless of the timing of the assessment. The MIBQ is appropriate for pregnant as well as postpartum women to assess maternal bonding toward the fetus and infant.

Diffusion and dissemination of a family peer-education program on mental disorders: a case study of the Omotenashi--Family Experiences Learning Program.

OBJECTIVES: The families of people with mental illnesses need sufficient opportunities to learn about such illnesses. Therefore, a family peer-education program about mental disorders, the Omotenashi - Family Experiences Learning Program, has been developed in Japan following the design of similar programs in the U.S. and Hong Kong. We aimed to clarify the factors related to the diffusion and dissemination of the program and to identify areas for improvement in its dissemination strategies. METHODS: This report was a case study based on the conceptual framework of the diffusion and dissemination of innovation in a health-care organization. The conceptual framework incorporates the adoption and routinization of the innovations by individuals and organizations in the external context. Interview data from fifteen family members in three family groups that had adopted the program were analyzed. They were interviewed about their backgrounds, the adoption of the program, and their experiences with the program implementation. We extracted descriptions based on the conceptual framework from the transcribed interview data and classified them into the framework components. We also compared the processes of adoption and routinization employed by the three family groups. RESULTS: Adoption processes were affected by the sense of crisis caused by decreased membership, member aging, and the necessity of policy change in family groups as well as the anticipation that the program may solve problems and the strength of the leader's intention to change and sustain the family group. Cooperative families and sufficient funding were necessary for the adoption of the program. Support from relevant organizational staff encouraged the family groups to adopt the program. Adopters encountered difficulties in gaining program participants but continued to take part in the program after realizing their anticipated positive results and receiving positive feedback from program participants. CONCLUSION: Our results suggest that the following may be effective for further dissemination of the program: an explanation about the ripple effects of the program on family groups and obtaining assistance from the relevant organizational staff in consulting for funding of the program and referring program participants.

[Factors related to adoption of a family peer-education program on mental disorders. Dissemination research of the Omotenashi-Family Experiences Learning Program].

OBJECTIVES: To identify effective dissemination strategies regarding a family peer-education program, the Omotenashi-Family Experiences Learning Program, on mental disorders, we evaluated factors related to the program adoption by family groups. METHODS: A cross-sectional mail survey was conducted from June to September 2013, involving 12 family group associations for mental disorders and their affiliated local family groups. For the analysis, we used the conceptual framework of diffusion and dissemination of innovations in a health-care organization. We divided the adaptation process into two steps: (1) understanding the program information, involved the level of program information sharing (with or without family group members); and (2) adaptation decision, involved the adaptation plan (planned or under consideration, or no plan). Data were analyzed regarding the differences between the two categories of the dependent variable in each step, and a logistic regression was conducted in the first step. RESULTS: Ten associations agreed to participate in the survey. Of the 177 family groups that had not adopted the program, 110 family groups responded to the survey (response rate 62.1%). In the first step, a municipal population where the family groups were located of over 10,000 (OR = 5.53, 95%CI; 1.93-15.89), influential individuals who strongly recommended the program (OR=5.22, 95%CI; 1.46-18.69), and information acquisition through the association (OR=3.41, 95% CI; 1.27-9.17) were related to the shared program information in the family group. In the second step, data from 39 family groups that shared the program information with family members were analyzed. The family groups with adaptation plans that were planned or under consideration had significantly more board members, labor, and motivated members compared to the family groups without adaptation plans. The former groups had significantly fewer concerns with the program's difficulties, risks, and tasks than the latter groups. The former groups expected significantly more memberships and more effective mutual member support, experienced greater correspondence between concerns of the family group or family group members and the program's content, and were not opposed to the program. CONCLUSION: Greater family-group awareness of the program could occur through the involvement of influential figures and provision of program information through family group associations. Program implementation involving other family groups and for non-group member families could lead to increased program adoption.

No associations found between the genes situated at 6p22.1, HIST1H2BJ, PRSS16, and PGBD1 in Japanese patients diagnosed with schizophrenia.

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 case-control 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.

Identification of ultra-rare disruptive variants in voltage-gated calcium channel-encoding genes in Japanese samples of schizophrenia and autism spectrum disorder.

Several large-scale whole-exome sequencing studies in patients with schizophrenia (SCZ) and autism spectrum disorder (ASD) have identified rare variants with modest or strong effect size as genetic risk factors. Dysregulation of cellular calcium homeostasis might be involved in SCZ/ASD pathogenesis, and genes encoding L-type voltage-gated calcium channel (VGCC) subunits Cav1.1 (CACNA1S), Cav1.2 (CACNA1C), Cav1.3 (CACNA1D), and T-type VGCC subunit Cav3.3 (CACNA1I) recently were identified as risk loci for psychiatric disorders. We performed a screening study, using the Ion Torrent Personal Genome Machine (PGM), of exon regions of these four candidate genes (CACNA1C, CACNA1D, CACNA1S, CACNA1I) in 370 Japanese patients with SCZ and 192 with ASD. Variant filtering was applied to identify biologically relevant mutations that were not registered in the dbSNP database or that have a minor allele frequency of less than 1% in East-Asian samples from databases; and are potentially disruptive, including nonsense, frameshift, canonical splicing site single nucleotide variants (SNVs), and non-synonymous SNVs predicted as damaging by five different in silico analyses. Each of these filtered mutations were confirmed by Sanger sequencing. If parental samples were available, segregation analysis was employed for measuring the inheritance pattern. Using our filter, we discovered one nonsense SNV (p.C1451* in CACNA1D), one de novo SNV (p.A36V in CACNA1C), one rare short deletion (p.E1675del in CACNA1D), and 14 NSstrict SNVs (non-synonymous SNV predicted as damaging by all of five in silico analyses). Neither p.A36V in CACNA1C nor p.C1451* in CACNA1D were found in 1871 SCZ cases, 380 ASD cases, or 1916 healthy controls in the independent sample set, suggesting that these SNVs might be ultra-rare SNVs in the Japanese population. The neuronal splicing isoform of Cav1.2 with the p.A36V mutation, discovered in the present study, showed reduced Ca2+-dependent inhibition, resulting in excessive Ca2+ entry through the mutant channel. These results suggested that this de novo SNV in CACNA1C might predispose to SCZ by affecting Ca2+ homeostasis. Thus, our analysis successfully identified several ultra-rare and potentially disruptive gene variants, lending partial support to the hypothesis that VGCC-encoding genes may contribute to the risk of SCZ/ASD.

Cross-Disorder Analysis of Genic and Regulatory Copy Number Variations in Bipolar Disorder, Schizophrenia, and Autism Spectrum Disorder.

BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (<100 kb) exonic deletions in BD, which contrasted with the highest burden of larger (>500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25-0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD.

Validation and factor analysis of the parental bonding instrument in Japanese pregnant women.

The Parental Bonding Instrument (PBI) evaluates parental attitudes derived from an individual's childhood experiences with their parents. The factor structure of the PBI differs depending on variables such as psychosocial factors including culture, race, sex, and psychological and social conditions of participants. Although previous studies of the relationships between perinatal depression and parenting experiences have used the factor structures of the PBI from the general population, it is unclear whether the same factor structures are appropriate in the highly variable perinatal period. In this study, complete responses to the PBI and the Edinburgh Postnatal Depression Scale (EPDS) were received from 932 primiparas at 25 weeks of gestation and at 1 month postpartum. An exploratory factor analysis was performed on half of the responses, and it was confirmed that the three factors were care, interference, and autonomy. Confirmatory factor analysis of the remaining half of the answers showed comprehensible fitness. Each factor showed a high degree of internal consistency, and each factor of the PBI correlated with the EPDS, indicating construct validity. The reliability and validity of the PBI in perinatal Japanese women were confirmed, and it was found that the PBI had a three-factor structure.

Perceived Social Support Partially Mediates the Impact of Temperament and Character on Postpartum Depression.

INTRODUCTION: Temperament and character of pregnant women, especially harm avoidance (HA) and self-directedness (SD) have been identified as risk factors for postpartum depression, in addition to poor social support. However, the relationship between these personality traits and social support for depressive symptoms after delivery has not been examined. METHODS: Data were extracted from a prospective cohort survey on pregnant women conducted in Nagoya, Japan that included the Temperament and Character Inventory (TCI), the Social Support Questionnaire (J-SSQ), and the Edinburgh Postnatal Depression Scale (EPDS) at approximately week 25 and 1 month postpartum. A mediation analysis using structural equation modeling (SEM) was used to test if social support in pregnancy is a mediator between personality traits and postpartum depressive symptoms. RESULTS: Thousand five hundred and fifty-nine women were included in the analysis. Both harm avoidance and SD were significantly associated with depressive symptoms (total effect: ß [SE], 0.298 [0.041], P < 0.001 for harm avoidance; total effect: ß [SE], -0.265 [0.067], P < 0.001 for SD). Mediation analysis showed that the effect of harm avoidance on depressive symptoms was partially mediated by low social support (direct effect: ß [SE], 0.193 [0.004], P < 0.001; indirect effect: ß [SE], 0.082 [0.034], P = 0.015). Self-directedness on depressive symptoms was not found to be mediated by low social support. CONCLUSION: Results indicate that poor social support worsens depressive symptoms in women with high HA during pregnancy. Limitations include a possible selection bias due to the limited target facilities; most variables being evaluated based on self-report questionnaires, and different number of samples available for analysis between harm avoidance and SD.

Influence of HTR2A polymorphisms and parental rearing on personality traits in healthy Japanese subjects.

Genetic factors and environmental influences contribute to the determination of human personality traits. This study examined the influence of serotonin receptor 2A polymorphisms and parental rearing on temperament. Subjects included 1245 Japanese volunteers (592 males and 653 females). Three single-nucleotide polymorphisms (SNPs) (rs6311, rs6313 and rs643627) were selected for genotyping. All subjects completed the 125-item Japanese short version of the temperament and character inventory, and 572 completed the Japanese version of the Parental Bonding Instrument. All SNPs were in Hardy-Weinberg equilibrium. A significant association (P=0.0026) was observed between rs643627 and novelty seeking in females. On the other hand, significant effects of maternal overprotection to harm avoidance (HA) were seen for rs6311 (P=0.0005), rs6313 (P=0.0004) and rs643627 (P=0.0003) in males only. In terms of the interaction of genotype and maternal overprotection with HA, interaction was observed in rs6311 (P=0.0290) and rs6313 (P=0.0230) in females only. Our results indicate a relationship between the rs643627 polymorphism and novelty seeking in females. In terms of serotonin receptor 2A gene polymorphisms and maternal overprotection, our findings suggest the existence of a gene-environmental interaction that influences HA.

Association study of ubiquitin-specific peptidase 46 (USP46) with bipolar disorder and schizophrenia in a Japanese population.

Recently, ubiquitin-specific peptidase 46 (Usp46) has been identified as a quantitative trait gene responsible for immobility in the tail suspension test and forced swimming test in mice. Mice with 3-bp deletion in Usp46 exhibited loss of 'behavioral despair' under inescapable stresses in addition to abnormalities in circadian behavioral rhythms and the GABAergic system. Considering the face and construct validity as an animal model for bipolar disorder, we explored an association of USP46 and bipolar disorder in a Japanese population. We also examined an association of USP46 and schizophrenia. We found nominal evidence for an association of rs12646800 and schizophrenia. This association was not significant after correction for multiple testing. No significant association was detected for bipolar disorder. In conclusion, our data argue against the presence of any strong genetic susceptibility factors for bipolar disorder or schizophrenia in the region USP46.

The effects of acute treatment with tandospirone, diazepam, and placebo on driving performance and cognitive function in healthy volunteers.

OBJECTIVE: To assess the effects of two anxiolytics, diazepam and tandospirone, on driving performance from methodological viewpoints taking frequent rear-end collisions into account. METHODS: In this double-blinded, three-way crossover trial, 18 healthy males received acute doses of 20 mg tandospirone (TSP), 5 mg diazepam (DZP), and placebo (PCB). The subjects were administered three driving tasks-road tracking, car following, and harsh braking-performed using a driving simulator and three cognitive tasks-Wisconsin Card Sorting Test, Continuous Performance Test, and N-back test-at baseline and at 1 and 4 h post-dosing. The Stanford Sleepiness Scale scores were also assessed. RESULTS: DZP nonsignificantly increased the percent change of brake reaction time (BRT) as compared to PCB at 4 h post-dosing. TSP nonsignificantly decreased the percent change of BRT as compared to PCB. Consequently, there was a significant difference in the percent change of BRT between DZP and TSP at 4 h post-dosing. For the remaining tasks, no statistically significant effects of treatment were observed. CONCLUSIONS: Acute doses of DZP significantly impaired the harsh-braking performance as compared to acute doses of TSP. These findings suggest that TSP may be used more safely in patients' driving activities.

Association study of bromodomain-containing 1 gene with schizophrenia in Japanese population.

Chromosome 22q13 region has been implicated in schizophrenia in several linkage studies. Genes within this locus are therefore promising genetic and biologic candidate genes for schizophrenia if they are expressed in the brain or predicted to have some role in brain development. A recent study reported that bromodomain-containing 1 gene (BRD1), located in 22q13, showed an association with schizophrenia in a Scottish population. Except for being a putative regulator of transcription, the precise function of BRD1 is not clear; however, expression analysis of BRD1 mRNA revealed widespread expression in mammalian brains. In our study, we explored the association of BRD1 with schizophrenia in a Japanese population (626 cases and 770 controls). In this association analysis, we first examined 10 directly genotyped single-nucleotide polymorphisms (SNPs) and 20 imputed SNPs. Second, we compared the BRD1 mRNA levels between cases and controls using lymphoblastoid cell lines (LCLs) derived from 29 cases and 30 controls. Although the SNP (rs138880) that previously has been associated with schizophrenia showed the same trend in the Japanese population, no significant association was detected between BRD1 and schizophrenia in our study. Similarly, no significant differences in BRD1 mRNA levels in LCLs were detected. Taken together, we could not strongly show that common SNPs in the BRD1 gene account for a substantial proportion of the genetic risk for schizophrenia in the Japanese population.