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Recent rapid progress in genome analysis and large-scale consortia has made it possible to discover variants with a variety of allele frequencies and effect sizes associated with psychiatric disorders. Among psychiatric disorder-susceptibility variants, rare variants with large effect sizes detected by sequencing analysis or array comparative genomic hybridization would be particularly useful for elucidating pathophysiology by developing disease models, such as genome-edited mouse or induced pluripotent stem cells. In the last decade, investigations of rare variants with large effect size have revealed an important role of neurodevelopment in the pathogenesis of psychiatric disorders. In future research, integration of recent evidence concerning the contribution of the immune system or gut microbiota will enhance our understanding of psychiatric disorders and facilitate novel drug development.

The smoking incentive in patients with schizophrenia (SCZ) depends on stimulation of nicotinic acetylcholine receptors (nAChRs) in the central nervous system. To detect potential predictor genes for nicotine responses in SCZ, we explored common factor using research data in human and animal samples. In lymphoblastoid cell lines from SCZ, the mRNA expression level of α7 nAChR subunit was decreased. In SCZ-like model mice of phencyclidine (PCP; 10 mg/kg/day, subcutaneously for 14 days)-administered mice, the mRNA expression level of α7 nAChR subunit and protein expression level of α7 or α4 nAChR subunit were significantly decreased in the prefrontal cortex during PCP withdrawal. Protein, but not mRNA, expression levels of α7, α4, and β2 nAChR subunits were significantly increased in the nucleus accumbens. Acute (-)-nicotine [(-)-NIC: 0.3 mg/kg, s.c.] treatment attenuated impairments of social behaviors and visual recognition memory. These effects of (-)-NIC were completely blocked by both methyllycaconitine, a selective α7 nAChR antagonist, and dihydro-β-erythroidine (DHβE), a selective α4β2 nAChR antagonist. (-)-NIC did not induce conditioned place preference, but enhanced sensitivity to methamphetamine-induced hyperactivity. These findings suggest that α7 nAChR is associated with development of disease and is implicated in the therapeutic effect of nicotine in SCZ. The smoking incentive in SCZ might be attributed to treat their own symptoms, rather than a result of (-)-NIC dependence, by stimulating α7 and/or α4β2 nAChRs.

Copy-number variations in the ARHGAP10 gene encoding Rho GTPase-activating protein 10 are associated with schizophrenia. Model mice (Arhgap10 S490P/NHEJ mice) that carry "double-hit" mutations in the Arhgap10 gene mimic the schizophrenia in a Japanese patient, exhibiting altered spine density, methamphetamine-induced cognitive dysfunction, and activation of RhoA/Rho-kinase signaling. However, it remains unclear whether the activation of RhoA/Rho-kinase signaling due to schizophrenia-associated Arhgap10 mutations causes the phenotypes of these model mice. Here, we investigated the effects of fasudil, a brain permeable Rho-kinase inhibitor, on altered spine density in the medial prefrontal cortex (mPFC) and on methamphetamine-induced cognitive impairment in a touchscreen‑based visual discrimination task in Arhgap10 S490P/NHEJ mice. Fasudil (20 mg/kg, intraperitoneal) suppressed the increased phosphorylation of myosin phosphatase-targeting subunit 1, a substrate of Rho-kinase, in the striatum and mPFC of Arhgap10 S490P/NHEJ mice. In addition, daily oral administration of fasudil (20 mg/kg/day) for 7 days ameliorated the reduced spine density of layer 2/3 pyramidal neurons in the mPFC. Moreover, fasudil (3-20 mg/kg, intraperitoneal) rescued the methamphetamine (0.3 mg/kg)-induced cognitive impairment of visual discrimination in Arhgap10 S490P/NHEJ mice. Our results suggest that Rho-kinase plays significant roles in the neuropathological changes in spine morphology and in the vulnerability of cognition to methamphetamine in mice with schizophrenia-associated Arhgap10 mutations.

Clinically, juveniles are more sensitive to stress than adults, and exposure to stress as juveniles prolongs psychiatric symptoms and causes treatment resistance. However, the efficacy of antidepressants for juveniles with psychiatric disorders is unknown. In the present study, we investigated whether the expression or development of impaired social behavior was attenuated by memantine, a non-competitive NMDA receptor antagonist. In addition, we clarified the molecular mechanisms related to intracellular signal transduction through NMDA receptors and the ameliorating effect of memantine in mice with impaired social behavior. Acute administration of memantine before the social interaction test, but not before exposure to social defeat stress, attenuated social behavioral impairment. A single social defeat stress increased the phosphorylation of NMDA receptor subunit GluN2A and extracellular-signal-related kinase 1/2 (ERK1/2). Memantine inhibited the increase of phosphorylated GluN2A and ERK1/2 resulting from social interaction behavior. In both GluN2A deficient and pharmacological blockaded mice, social behavioral impairment was not observed in the social interaction test through regulation of ERK1/2 phosphorylation. These findings suggest that memantine ameliorates social behavioral impairment in mice exposed to a single social defeat stress as juveniles by regulating the NMDA receptor and subsequent ERK1/2 signaling activation. Memantine may constitute a novel therapeutic drug for stress-related psychiatric disorders in juveniles with adverse juvenile experiences.

Blonanserin differs from other antipsychotic drugs, such as risperidone and olanzapine, and exhibits a higher affinity for dopamine-D2/3 receptors than for serotonin 5-HT2A receptors. We investigated the involvement of dopamine-D3 receptors in the effect of blonanserin on the social deficit observed in an animal model of schizophrenia and sought to elucidate the molecular mechanism underlying its action. Mice received phencyclidine (PCP: 10 mg/kg/day, s.c.), a non-competitive N-methyl- d -aspartate (NMDA) receptor antagonist, once a day for 14 consecutive days. We then evaluated the sociability, using a social interaction test, and the expression of GluN1 subunit, an essential subunit of the NMDA receptors, in these mice. Blonanserin significantly ameliorated the PCP-induced social deficit, whereas olanzapine and haloperidol did not. This effect of blonanserin was antagonized by 7-OH-DPAT, a dopamine-D3 receptor agonist, and SCH23390, a dopamine-D1 receptor antagonist. However, the ameliorating effect of blonanserin was not inhibited by DOI, a serotonin 5-HT2A receptor agonist. The PCP-induced social deficit was also ameliorated by U99194, a dopamine-D3 receptor antagonist and SKF38393, a dopamine-D1 receptor agonist, being effects antagonized by 7-OH-DPAT or SCH23390. Blonanserin significantly inhibited the decrease in the phosphorylation levels of GluN1 at Ser897 by protein kinase A (PKA) in the prefrontal cortex (PFC) in PCP administered mice. These results suggest that activation of NMDA receptors due to Ser897-phosphorylation of GluN1 subunit, which is a step linked to dopamine-D1 receptor-PKA signaling through dopamine-D3 receptor antagonism in the PFC, is required for the ameliorating effect of blonanserin on the PCP-induced social deficit. These findings also provide in vivo evidence that blonanserin antagonism of the dopamine-D3 receptors may be useful as a novel treatment strategy and that the dopamine-D3 receptors can be a novel therapeutic target molecule for the social deficit observed in schizophrenia.

Background Many women experience depressive symptoms during pregnancy and postpartum periods. These depressive symptoms are often accompanied by other inflammatory morbidities present during pregnancy. Tryptophan (TRP) metabolism has attracted considerable attention due to its influence on the onset of depression via induction of inflammation. We examined the changes in plasma levels of TRP metabolites in pregnant women with depressive symptoms during pregnancy and/or the postpartum period. Methods In line with a previous analysis using the Edinburgh Postnatal Depression Scale (EPDS), participants were divided into a non-depressive (ND) group, a postpartum depressive (PD) group, a temporary gestational depressive (TG) group, and a continuous depressive (CD) group. Blood samples were collected before and 1 month after delivery. The concentrations of plasma TRP metabolites were measured using high-performance liquid chromatography (HPLC). Results There are differences in plasma levels of TRP metabolites during pregnancy and postpartum periods between the ND group and the PD group, but not the TG or CD group. In the PD group, plasma levels of kynurenine (KYN) and kynurenic acid (KA), and KYN/TRP and KA/KYN ratio during the pregnancy period were higher and 3-hydroxyanthranilic acid (3HAA) during the postpartum period was lower than those in the ND group. Limitations Histories regarding mood disorders before pregnancy were not assessed. Conclusions The higher plasma levels of KYN and KA, and KYN/TRP and KA/KYN ratio during pregnancy period and lower plasma level of 3HAA during the postpartum period could be useful predictive and diagnostic markers of postpartum depressive symptoms.

Background Although previous studies have reported associations between bonding failure, depression, social support among mothers, and perceived rearing, the causal relationships remain unclear. Methods A total of 855 women (mean age, 32.4 ± 4.4 years) completed the Mother-Infant Bonding Questionnaire (MIBQ), the Edinburgh Postnatal Depression Scale (EPDS), the Japanese version of the Social Support Questionnaire, and the Parental Bonding Instrument in early pregnancy before week 25 (T1) and at 1 month after delivery (T2). We created a path model to clarify the causal relationships between perinatal bonding failure, depression, social support, and perceived rearing during pregnancy and at 1 month after delivery. The model was tested using structural equation modeling. Results Our recursive model showed acceptable fit (chi-squared statistic/degree of freedom = 2.1, comparative fit index = 0.98, root mean square error of approximation = 0.04). It was revealed that: (1) at T1, higher overprotection significantly predicted MIBQ scores; (2) at T1, poorer social support significantly predicted both MIBQ and EPDS scores; and (3) at T1, both MIBQ and EPDS scores significantly predicted respective scores at T2. Conclusions These results showed that bonding failure in the postpartum period was significantly influenced by mothers' own perceived rearing and social support during pregnancy. In addition, depression in the postpartum period was strongly influenced by social support during pregnancy. These findings suggest that psychosocial interventions that focus on both mothers' recollections of their own upbringing and social support during pregnancy are effective for preventing bonding failure and depression in the postpartum period.

Summary: Compelling evidence in Caucasian populations suggests a role for copy-number variations (CNVs) in autism spectrum disorder (ASD) and schizophrenia (SCZ). We analyzed 1,108 ASD cases, 2,458 SCZ cases, and 2,095 controls in a Japanese population and confirmed an increased burden of rare exonic CNVs in both disorders. Clinically significant (or pathogenic) CNVs, including those at 29 loci common to both disorders, were found in about 8% of ASD and SCZ cases, which was significantly higher than in controls. Phenotypic analysis revealed an association between clinically significant CNVs and intellectual disability. Gene set analysis showed significant overlap of biological pathways in both disorders including oxidative stress response, lipid metabolism/modification, and genomic integrity. Finally, based on bioinformatics analysis, we identified multiple disease-relevant genes in eight well-known ASD/SCZ-associated CNV loci (e.g., 22q11.2, 3q29). Our findings suggest an etiological overlap of ASD and SCZ and provide biological insights into these disorders. : Kushima et al. perform comparative analyses of CNVs in ASD and SCZ in a Japanese population. They identify pathogenic CNVs and biological pathways in each disorder with significant overlap. Patients with pathogenic CNVs have a higher prevalence of intellectual disability. Disease-relevant genes are detected in eight well-known ASD/SCZ-associated CNV loci. Keywords: autism spectrum disorder, schizophrenia, copy-number variation, array comparative genomic hybridization, genetic overlap, Japanese population, oxidative stress response, genome integrity, lipid metabolism, gene ontology

Duplications at the 15q11.2-q13.1 region are associated with psychiatric disorders such as developmental delay and autism spectrum disorder. However, the specific influence of these duplications on human neuronal cells remains unclear. Here we generated induced pluripotent stem cells (iPSCs) derived from a patient with 15q11.2-q13.1 duplication syndrome. The generated iPSCs carried 15q11.2-q13.1 duplication and showed typical iPSC morphology and pluripotency marker expression, and the capacity to differentiate into three germ layers. These iPSC lines will contribute to further understanding the pathology of 15q11.2-q13.1 duplication syndrome and help develop drugs to treat psychiatric disorders.

Resting-state (rs) functional magnetic resonance imaging (fMRI) studies have revealed dysfunctional thalamocortical functional connectivity (FC) in schizophrenia. However, the relationship between thalamocortical FC and cognitive impairment has not been thoroughly investigated. We hypothesized that aberrant thalamocortical FC is related to attention deficits in schizophrenia. Thirty-eight patients with schizophrenia and 38 matched healthy controls underwent rs-fMRI and task fMRI while performing a Flanker task. We observed decreased left thalamic activation in patients with schizophrenia using task fMRI to determine the thalamic seed. A seed-based analysis using this seed was performed in the whole brain to assess differences in thalamocortical FC between the groups. Significantly worse performance was observed in the patient group. The rs-fMRI analysis revealed significantly increased FC between the left thalamus seed and the occipital cortices/postcentral gyri in patients when compared to controls. In the patient group, significant positive correlations were observed between the degree of FC from the left thalamus to the bilateral occipital gyri, which correspond to the visual cortex, and the Flanker effect. No significant correlation was detected in the control group. These results indicate that aberrant FC between the left thalamus and the visual cortex is related to attention deficits in schizophrenia.

Astrotactin-2, encoded by ASTN2, is implicated in neuronal migration. Although genetic studies of schizophrenia (SCZ) patients have suggested that exonic deletions of ASTN2 are associated with neurodevelopmental and psychiatric disorders, their biological significance remains unclear. Herein, we generated human induced pluripotent stem cells (iPSCs) from a SCZ patient with an exonic deletion of ASTN2. The generated iPSCs carried ASTN2 deletion and showed typical iPSC morphology, pluripotency marker expression, normal chromosomal aneuploidy, and the capacity to differentiate into three germ layers. This iPSC line may be suitable for evaluating Astrotactin-2 function relevant for SCZ onset in the human brain.

Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy (NIRS). Methods: A total of 23 healthy young adults (age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time (TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test (WCST), and the Continuous Performance Test–Identical Pairs (CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS. Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks (r = −0.602, p = 0.002; r = −0.446, p = 0.033, respectively), whereas TST was significantly correlated with % corrects on the 2-back task (r = 0.486, p = 0.019). Multiple regression analysis, including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks (β = −0.634, p = 0.002; β = −0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task (β = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area (r = 0.492, p = 0.017). Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory. Keywords: Cortical oxygenation, Executive function, Exercise, Sustained attention, Total sleep time, Working memory

Summary The thalamus is critical for the brain's integrative hub functions; however, the localization and characterization of the different thalamic hubs remain unclear. Using a voxel-level network measure called functional connectivity overlap ratio (FCOR), we examined the thalamus' association with large-scale resting-state networks (RSNs) to elucidate its connector hub roles. Connections to the core-neurocognitive networks were localized in the anterior and medial parts, such as the anteroventral and mediodorsal nuclei areas. Regions functionally connected to the sensorimotor network were distinctively located around the lateral pulvinar nucleus but to a limited extent. Prominent connector hubs include the anteroventral, ventral lateral, and mediodorsal nuclei with functional connections to multiple RSNs. These findings suggest that the thalamus, with extensive connections to most of the RSNs, is well placed as a critical integrative functional hub and could play an important role for functional integration facilitating brain functions associated with primary processing and higher cognition., Graphical abstract, Highlights • Multiple large-scale cortical networks converged in the thalamus • Neurocognitive associated hub existed in the anterior and medial region • Control-processing hub localized in the intermediate thalamus • Sensorimotor network was located around the lateral pulvinar nucleus, Systems neuroscience; Sensory neuroscience; Cognitive neuroscience; Neural networks

We present the largest exome sequencing study of autism spectrum disorder (ASD) to date (n=35,584 total samples, 11,986 with ASD). Using an enhanced Bayesian framework to integrate de novo and case-control rare variation, we identify 102 risk genes at a false discovery rate ≤ 0.1. Of these genes, 49 show higher frequencies of disruptive de novo variants in individuals ascertained for severe neurodevelopmental delay, while 53 show higher frequencies in individuals ascertained for ASD; comparing ASD cases with mutations in these groups reveals phenotypic differences. Expressed early in brain development, most of the risk genes have roles in regulation of gene expression or neuronal communication (i.e., mutations effect neurodevelopmental and neurophysiological changes), and 13 fall within loci recurrently hit by copy number variants. In human cortex single-cell gene expression data, expression of risk genes is enriched in both excitatory and inhibitory neuronal lineages, consistent with multiple paths to an excitatory/inhibitory imbalance underlying ASD.

Background Growth-associated protein 43 (GAP43), a synaptic protein involved in axonal growth and synaptic plasticity, is implicated in the pathophysiology of autism spectrum disorder (ASD) and schizophrenia. To examine the role of rare GAP43 variants in the genetic etiology of ASD and schizophrenia in a Japanese population, we performed resequencing and association analysis. Methods First, we resequenced the GAP43 coding region in 295 ASD patients, 323 schizophrenia patients and 304 controls. Second, we genotyped rs561268447 in 273 ASD patients, 1,150 schizophrenia patients and 1,022 controls. Third, we performed an association analysis of rs561268447 in 568 ASD patients, 1,473 schizophrenia patients and 10,127 controls. Results We identified a rare putatively damaging missense variant (rs561268447) in an ASD patient via resequencing. However, we did not detect the variant in 2,445 individuals via genotyping. The variant was not significantly associated with ASD or schizophrenia in the association analysis. Conclusion This study does not provide evidence for the contribution of rare GAP43 variants to ASD or schizophrenia susceptibility in the Japanese population.

Particular support needs of perinatal women in a disaster have been difficult to grasp through preexisting quantitative epidemiological studies. This study aimed to extract concerns that must be considered for perinatal women's mental healthcare in postdisaster settings based on lessons from the Great East Japan Earthquake. Narrative messages regarding protective and risk factors for mothers' mental health from a representative population of mothers who had given birth and all official maternal caregivers, in a coastal town devastated by the catastrophe were subjected to qualitative analyses. Eight concerns were extracted as specific support needs: (1) improve information pathways, (2) maintain access to medical services, (3) sufficiently equip necessary items for perinatal women and children, (4) implement hygienic facilities, (5) prevent mothers from feeling diffidence, (6) encourage mothers to focus on positive aspects of being pregnant or taking care of their babies, (7) provide dedicated paths for relief supply distribution and dedicated rooms for mothers and children in shelters, and (8) resume usual healthcare activities as soon as possible. The comprehensive survey of the affected community presented concerns that needed to be considered for perinatal women's mental health in postdisaster settings.

Our previous study showed that enhanced carbonyl stress is closely related to schizophrenia. The endogenous secretory receptor for advanced glycation end-products (esRAGE) is a splice variant of the AGER gene and is one of the soluble forms of RAGE. esRAGE is considered to be a key molecule for alleviating the burden of carbonyl stress by entrapping advanced glycation end-products (AGEs). In the current study, we conducted genetic association analyses focusing on AGER, in which we compared 212 schizophrenic patients to 214 control subjects. We also compared esRAGE levels among a subgroup of 104 patients and 89 controls and further carried out measurements of total circulating soluble RAGE (sRAGE) in 25 patients and 49 healthy subjects. Although the genetic association study yielded inconclusive results, multiple regression analysis indicated that a specific haplotype composed of rs17846798, rs2071288, and a 63 bp deletion, which were in perfect linkage disequilibrium (r2 = 1), and rs2070600 (Gly82Ser) were significantly associated with a marked decrease in serum esRAGE levels. Furthermore, compared to healthy subjects, schizophrenia showed significantly lower esRAGE (p = 0.007) and sRAGE (p = 0.03) levels, respectively. This is the first study to show that serum esRAGE levels are regulated by a newly identified specific haplotype in AGER and that a subpopulation of schizophrenic patients are more vulnerable to carbonyl stress.

Clozapine is an effective antipsychotic for treatment-resistant schizophrenia, but can cause fatal hematopoietic toxicity as agranulocytosis. To elucidate the mechanism of hematopoietic toxicity induced by clozapine, we developed an in vitro assay system using HL-60 cells, and investigated the effect on hematopoiesis. HL-60 cells were differentiated by all-trans retinoic acid (ATRA) into three states according to the following hematopoietic process: undifferentiated HL-60 cells, those undergoing granulocytic ATRA-differentiation, and ATRA-differentiated granulocytic cells. Hematopoietic toxicity was evaluated by analyzing cell survival, cell proliferation, granulocytic differentiation, apoptosis, and necrosis. In undifferentiated HL-60 cells and ATRA-differentiated granulocytic cells, both clozapine (50 and 100μM) and doxorubicin (0.2µM) decreased the cell survival rate, but olanzapine (1-100µM) did not. Under granulocytic differentiation for 5days, clozapine, even at a concentration of 25μM, decreased survival without affecting granulocytic differentiation, increased caspase activity, and caused apoptosis rather than necrosis. Histamine H4 receptor mRNA was expressed in HL-60 cells, whereas the expression decreased under granulocytic ATRA-differentiation little by little. Both thioperamide, a histamine H4 receptor antagonist, and DEVD-FMK, a caspase-3 inhibitor, exerted protection against clozapine-induced survival rate reduction, but not of live cell counts. 4-Methylhistamine, a histamine H4 receptor agonist, decreased the survival rate and live cell counts, as did clozapine. HL-60 cells under granulocytic differentiation are vulnerable under in vitro assay conditions to hematopoietic toxicity induced by clozapine. Histamine H4 receptor is involved in the development of clozapine-induced hematopoietic toxicity through apoptosis, and may be a potential target for preventing its occurrence through granulocytic differentiation.

Selective serotonin reuptake inhibitors are the first-line antidepressants for treating major depressive and post-traumatic stress disorders. These inhibitors directly bind to the serotonin transporter (SERT). Protein kinase C (PKC) is a key regulator of SERT functions as it can attenuate SERT activity through phosphorylation and its subsequent internalization. However, whether PKC-regulated SERT functions are involved in emotional impairment in a mouse model of stress remains unclear. Using a mouse model of swim-induced stress, we investigated whether the PKC-SERT system is involved in emotional impairment and tried to identify the PKC isoforms involved in this mechanism. Mice exposed to swim stress showed enhanced immobility and decreased social interaction times compared to those in swim stress-naive mice. Moreover, significant decreases in phosphorylated PKCβI and SERT levels were observed in the prefrontal cortex of stressed mice compared to those of swim stress-naive mice. No changes in levels of other phosphorylated PKC isoforms were observed between the two groups. Phorbol 12-myristate 13-acetate (a PKC activator) administration significantly attenuated enhanced immobility and decreased social interaction time in stressed mice and increased the serotonin turnover. Further, the PKC activator increased levels of phosphorylated PKCβI or SERT and decreased cell surface localization of SERT in stressed mice. Contrary to this, chelerythrine (a PKC inhibitor) administration exacerbated the immobility and sociality of mice exposed to mild stress. Our results suggest that PKCβI activation attenuates emotional impairment by suppressing SERT function in stressed mice. Thus, PKCβI may be a key target for the development of new treatment strategies for emotional impairment in stress-related disorders.

Objective This case–control study investigated the relationship between the risk of Autism Spectrum Disorder (ASD) onset, and early exposure to the combined Measles–Mumps–Rubella (MMR) vaccine and thimerosal consumption measured from vaccinations in the highly genetically homogenous Japanese population. Methods Vaccination histories at 1, 3, 6, 12, 18, 24, and 36 months from birth were investigated in ASD cases (189 samples), and controls (224 samples) matching age and sex in each case. Crude odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to determine relationship between MMR vaccination and ASD. The differences in mean values of the thimerosal dosage between cases and controls were analyzed using an unpaired t -test. MMR vaccination and thimerosal dosage were also investigated using a conditional multiple-regression model. Results There were no significant differences in MMR vaccination and thimerosal dosage between cases and controls at any age. Furthermore, the ORs (95% CIs) of MMR vaccination and thimerosal dosage associated with ASD in the conditional multiple regression model were, respectively, 0.875 (0.345–2.222) and 1.205 (0.862–1.683) at age 18 months, 0.724 (0.421–1.243) and 1.343 (0.997–1.808) at 24 months, and 1.040 (0.648–1.668) and 0.844 (0.632–1.128) at 36 months. Thus, there were no significant differences. Conclusions No convincing evidence was found in this study that MMR vaccination and increasing thimerosal dose were associated with an increased risk of ASD onset.

An altered sulcogyral pattern in the orbitofrontal cortex (OFC) has been implicated in schizophrenia as a possible marker of abnormal neurodevelopment, while its genetic mechanism remains unknown. This magnetic resonance imaging study investigated the relationship between the polymorphism of YWHAE (rs28365859), a gene encoding 14-3-3epsilon that is a Disrupted-in-Schizophrenia 1 (DISC1)-interacting molecule associated with neuronal development, and the OFC subtypes of the ‘H-shaped’ sulcus (Types I, II, and III) in a Japanese sample of 72 schizophrenia patients and 86 healthy controls. The schizophrenia patients had significantly increased Type III (p = 0.004) and decreased Type I (p = 0.013) expression on the right hemisphere compared to the controls. The subjects carrying the protective C allele showed a decrease in Type III (p = 0.005) and an increase in Type I (p = 0.017) compared to the G allele homozygotes, especially for the healthy subjects in the left hemisphere. These results suggest a possible role for the YWHAE genotype in the early development of the OFC sulcogyral pattern, but its effect alone is not likely to explain the altered sulcogyral pattern in schizophrenia.

Cumulative incidences of multiple risk factors are related to pathology of psychiatric disorders. The present study was designed to examine combinative effects of a neonatal immune challenge with adolescent abused substance treatment on the psychological behaviors and molecular expressions in the adult. C57BL/6J mice were neonatally treated, with polyriboinosinic-polyribocytidylic acid (PolyI:C: 5mg/kg) during postnatal days (PD) 2-6, then with phencyclidine (PCP: 10mg/kg) during adolescence (PD35-41). Locomotor activity was analyzed to evaluate sensitivity to PCP on PD35 and PD41. Emotional and cognitive tests were carried out on PD42-48. Neonatal PolyI:C treatment markedly enhanced sensitivity to PCP- and methamphetamine-induced hyperactivity in the adolescent. Mice treated with both neonatal PolyI:C and adolescent PCP (PolyI:C/PCP) showed social deficit and object recognition memory impairment. The expression of glutamate/aspartate transporter (GLAST) in the prefrontal cortex (PFC) was significantly increased in the (PolyI:C/PCP)-treated mice. Infusion of glutamate transporter inhibitor (DL-TBOA: 1 nmol/bilaterally) into the PFC reversed the object recognition impairment in the (PolyI:C/PCP)-treated mice. These results indicate that the combined treatment of neonatal PolyI:C with adolescent PCP leads to behavioral abnormalities, which were associated with increase of GLAST expression in the adult PFC.

Background RTN4R (Reticulon 4 receptor) plays an essential role in regulating axonal regeneration and plasticity in the central nervous system through the activation of rho kinase, and is located within chromosome 22q11.2, a region that is known to be a hot-spot for Schizophrenia (SCZ) and Autism Spectrum Disorder (ASD). Recently, rare variants such as Copy Number Variants (CNV) and Single Nucleotide Variants (SNV) have been a focus of research because of their large effect size associated with increased susceptibility to SCZ and ASD and the possibility of elucidating the pathophysiology of mental disorder through functional analysis of the discovered rare variants. Methods In order to discover rare variants with large effect size and to explore their role in the etiopathophysiology of SCZ and ASD, we performed mutation screening of RTN4R coding exons using a sample comprised of 370 SCZ and 192 ASD patients, and association analysis using a large number of unrelated individuals (1716 SCZ, 382 ASD and 4009 controls). Results Through this mutation screening, we discovered four rare (minor allele frequency Discussion This study strengthens the evidence for association between rare variants within RTN4R and SCZ, and may shed light on the molecular mechanisms underlying the neurodevelopmental disorder.

Background NRXN1 is a transmembrane protein having a fundamental role in synaptogenesis, synaptic maintenance, neurotransmitter release, and the function of voltage-gated calcium channels in the synapses of brainstem and neocortex. Impairments in NRXN1 caused by genetic variants are thought to be critical for the pathomechanisms in neuropsychiatric disorders including autism spectrum disorders and schizophrenia. Methods In this study, we conducted exon-targeted resequencing of the NRXN1 gene with next-generation sequencing technology in 562 Japanese patients (192 with idiopathic autism and 370 with schizophrenia). We then performed in silico analyses, trio analyses, and association analyses on 1,892 cases (381 autism and 1,511 schizophrenia) and 1,291 controls with these variants. Results We detected six heterozygous variants with allele frequencies of ≤1%. We regarded three missense variants (p.T777M, p.D812G, p.R896W) as novel ones because they were predicted to be damaging based on in silico predictions and because each was not registered in either HGVD or iJGVD, the Japanese public databases. Among these three cases, two involved transmission from a healthy mother to her autistic son, and one involved transmission from a healthy mother to her schizophrenia daughter. We found no statistically significant association for any of three rare point variants in NRXN1 with case-control analysis. Discussion We explored the role of rare NRXN1 variants in Japanese neuropsychiatric disorders. To assess the impact of the variants discovered here, further investigation by sample size expansion and biological analysis will be performed.

Objective This randomized, placebo-controlled study evaluated the efficacy and safety of a fixed dose (3 mg/day) and flexible dose (3–15 mg/day) schedule of aripiprazole as augmentation therapy in Japanese patients with inadequate response to antidepressant therapy (ADT). Method During an 8-week prospective treatment phase, patients experiencing a major depressive episode received clinicians' choice of ADT. Subjects with inadequate response to ADT were randomized to receive adjunctive treatment with placebo (n=195), fixed dose aripiprazole (n=197) or flexible dose aripiprazole (n=194) for 6 weeks. The primary efficacy endpoint was mean change in the Montgomery–Asberg Depression Rating Scale (MADRS) total score from the end of prospective treatment (baseline) to the end of randomized treatment. Results More than 90% of patients in all treatment groups completed the 6-week double-blind treatment phase. Mean MADRS total score was improved to a significantly greater extent with fixed dose aripiprazole and flexible dose aripiprazole (−10.5 and −9.6, respectively) than with placebo (−7.4). Aripiprazole was well tolerated. The incidence of akathisia observed in the flexible dose group may relate to a higher prevalence of the CYP2D6*10 allele in Asian populations. Limitations Six weeks of adjunctive treatment is insufficient to draw conclusions about the long-term benefits of aripiprazole. Exclusion of patients with established medical comorbidities does not reflect real-world practice. Conclusions Aripiprazole augmentation at a fixed or flexible dose was superior to ADT alone and was reasonably well tolerated in Japanese patients with inadequate response to ADT. Clinical trials registration ClinicalTrials.gov identifier NCT00876343.

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.

Background Solid evidence links schizophrenia (SZ) susceptibility to neurodevelopmental processes involving tyrosine phosphorylation-mediated signaling. Mouse studies implicate the Ptpra gene, encoding protein tyrosine phosphatase RPTPα, in the control of radial neuronal migration, cortical cytoarchitecture, and oligodendrocyte differentiation. The human gene encoding RPTPα, PTPRA , maps to a chromosomal region (20p13) associated with susceptibility to psychotic illness. Methods We characterized neurobehavioral parameters, as well as gene expression in the central nervous system, of mice with a null mutation in the Ptpra gene. We searched for genetic association between polymorphisms in PTPRA and schizophrenia risk (two independent cohorts, 1420 cases and 1377 controls), and we monitored PTPRA expression in prefrontal dorsolateral cortex of SZ patients (35 cases, 2 control groups of 35 cases). Results We found that Ptpra −/− mice reproduce neurobehavioral endophenotypes of human SZ: sensitization to methamphetamine-induced hyperactivity, defective sensorimotor gating, and defective habituation to a startle response. Ptpra loss of function also leads to reduced expression of multiple myelination genes, mimicking the hypomyelination-associated changes in gene expression observed in postmortem patient brains. We further report that a polymorphism at the PTPRA locus is genetically associated with SZ, and that PTPRA mRNA levels are reduced in postmortem dorsolateral prefrontal cortex of subjects with SZ. Conclusions The implication of this well-studied signaling protein in SZ risk and endophenotype manifestation provides novel entry points into the etiopathology of this disease.

Objectives Recently, we detected that the prokineticin 2 receptor gene was associated with not only major depressive disorder (MDD) but also methamphetamine dependence. Therefore, it is possible that mood disorders and drug addiction have shared susceptibility genes. The translin-associated factor X gene ( TSNAX )/disrupted-in-schizophrenia-1 gene ( DISC1 ) has been associated with psychiatric disorders, including schizophrenia, MDD and bipolar disorder. TSNAX is located immediately upstream of DISC1 and has been shown to undergo intergenic splicing with DISC1 . Based on this evidence, we hypothesized that TSNAX might be a good candidate gene for methamphetamine dependence. Methods We conducted a case-control study of Japanese individuals (215 with methamphetamine dependence and 318 age- and sex-matched controls) with three tagging SNPs (rs1630250, rs766288 and rs6662926) selected by HapMap database. Results rs1630250 was associated in males with methamphetamine dependence in the allele analysis ( P -value: 0.0253). However, these results did not remain significant after Bonferroni correction to adjust for multiple comparisons (corrected P -value: 0.152). Conclusion Our findings suggest that TSNAX does not play a role in methamphetamine dependence in the Japanese population. A replication study using larger samples needs to be conducted to obtain conclusive results.

BACKGROUND: Genome-wide association studies have detected a small number of weak but strongly supported schizophrenia risk alleles. Moreover, a substantial polygenic component to the disorder consisting of a large number of such alleles has been reported by the International Schizophrenia Consortium. METHOD: We report a Japanese genome-wide association study of schizophrenia comprising 575 cases and 564 controls. We attempted to replicate 97 markers, representing a nonredundant panel of markers derived mainly from the top 150 findings, in up to three data sets totaling 1990 cases and 5389 controls. We then attempted to replicate the observation of a polygenic component to the disorder in the Japanese and to determine whether this overlaps that seen in UK populations. RESULTS: Single-locus analysis did not reveal genome-wide support for any locus in the genome-wide association study sample (best p = 6.2 × 10(-6)) or in the complete data set in which the best supported locus was SULT6B1 (rs11895771: p = 3.7 × 10(-5) in the meta-analysis). Of loci previously supported by genome-wide association studies, we obtained in the Japanese support for NOTCH4 (rs2071287: p(meta) = 5.1 × 10(-5)). Using the approach reported by the International Schizophrenia Consortium, we replicated the observation of a polygenic component to schizophrenia within the Japanese population (p = .005). Our trans Japan-UK analysis of schizophrenia also revealed a significant correlation (best p = 7.0 × 10(-5)) in the polygenic component across populations. CONCLUSIONS: These results indicate a shared polygenic risk of schizophrenia between Japanese and Caucasian samples, although we did not detect unequivocal evidence for a novel susceptibility gene for schizophrenia.

Diffuse neurofibrillary tangles with calcification (DNTC) is a relatively rare presenile dementia that clinically shows overlapping symptoms of Alzheimer's disease and frontotemporal lobar degeneration (FTLD). DNTC is pathologically characterized by localized temporal or frontotemporal atrophy with massive neurofibrillary tangles, neuropil threads and Fahr's-type calcification without senile plaques. We tried to clarify the molecular basis of DNTC by immunohistochemically examining the appearance and distribution of accumulated alpha-synuclein (aSyn) and TAR DNA-binding protein of 43 kDa (TDP-43) in the brains of 10 Japanese autopsy cases. We also investigated the clinically characteristic symptoms from the clinical charts and previous reports, and the correlations with neuropathological findings. The characteristic symptoms were evaluated using the Neuropsychiatric Inventory Questionnaire (NPI-Q). As a result, we confirmed the high frequency of neuronal cytoplasmic accumulation of aSyn (80%) and phosphorylated TDP-43 (90%) in DNTC cases. There was a significant correlation between some selected items of NPI-Q scores and the severity of the limbic TDP-43 pathology. The pathology of DNTC included TDP-43 and aSyn pathology with high frequency. These abnormal accumulations of TDP-43 might be involved in the pathological process of DNTC, having a close relationship to the FTLD-like psychiatric symptoms during the clinical course.

Background Altered serotonergic neural transmission is hypothesized to be a susceptibility factor for psychotic disorders such as schizophrenia. The serotonin 6 (5-HT6) receptor is therapeutically targeted by several second generation antipsychotics, such as clozapine and olanzapine, and d -amphetamine-induced hyperactivity in rats is corrected with the use of a selective 5-HT6 receptor antagonist. In addition, the disrupted prepulse inhibition induced by d -amphetamine or phencyclidine was restored by 5-HT6 receptor antagonist in an animal study using rats. These animal models were considered to reflect the positive symptoms of schizophrenia, and the above evidence suggests that altered 5-HT6 receptors are involved in the pathophysiology of psychotic disorders. The symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an analysis of the association of the 5-HT6 gene (HTR6) with METH-induced psychosis. Method Using five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997), we conducted a genetic association analysis of case–control samples (197 METH-induced psychosis patients and 337 controls) in the Japanese population. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients. Results rs6693503 was associated with METH-induced psychosis patients in the allele/genotype-wise analysis. Moreover, this association remained significant after Bonferroni correction. In the haplotype-wise analysis, we detected an association between two markers (rs6693503 and rs1805054) and three markers (rs6693503, rs1805054 and rs4912138) in HTR6 and METH-induced psychosis patients, respectively. Conclusion HTR6 may play an important role in the pathophysiology of METH-induced psychosis in the Japanese population.

Background Depression influences a worker's productivity and health substantially. Recently, the Japanese society and government reported that working overtime is one of the primary causes of depression and suicide in workers. However, only a few studies have investigated the relation between overtime hours and mental health status, and conclusions vary. In addition, prior findings are inconsistent in terms of the relation between depression and lifestyle factors, including alcohol intake and smoking. Additional studies are required to clarify the relation between possible risk factors and depression in Japanese workers. Methods We performed a case-control and a cohort study. Subjects were office workers in four Japanese companies. Diagnosis of depression was made by two psychiatrists who conducted independent clinical interviews using DSM-IV-TR criteria. Results There was no significant association between working overtime and the onset of depression. The frequency of alcohol intake was significantly related to the onset of depression. We also found a significant relation between younger age and depression onset. Body mass index and physical illness, including diabetes mellitus, had no significant association with depression onset. Limitations Data were self-reported and the number of included female workers was small. Conclusions Reducing working hours alone is unlikely to be effective in preventing workers' depression. Additional countermeasures are needed, including a reduction in alcohol intake and work stress. Considerations for younger workers are also needed.

Methylenetetrahydrofolate reductase (MTHFR) is a critical molecule for single-carbon transfer reactions. Recent evidence suggests that polymorphisms of MTHFR are related to neural tube deficits and the pathogenesis of schizophrenia. While several studies have demonstrated associations between the gene encoding the MTHFR ( MTHFR ) polymorphisms and schizophrenia, these studies lack consistency. Therefore, we conducted a gene-wide association study (patients with schizophrenia = 696, control subjects = 747) and performed imputation analysis. Additionally, we performed meta-analysis on currently available data from 18 studies for two common functional polymorphisms (rs1801131 and rs1801133). There were no significant associations with schizophrenia in the single marker analysis for the seven tagging SNPs of MTHFR . In the haplotypic analysis, a nominally significant association was observed between the haplotypes, which included four SNPs (rs1801133, rs17421511, rs17037396, and rs9651118) and the schizophrenic patients. Additionally, the imputation analysis demonstrated there were several associated markers on the MTHFR chromosomal region. However, confirmatory analyses of three tagging SNPs (rs1801133, rs17037396, and rs9651118) and the top SNP (rs17421511) for the imputation results (patients with schizophrenia = 797, control subjects = 1025) failed to replicate the haplotypic analysis and the imputation results. These findings suggest that MTHFR polymorphisms are unlikely to be related to the development of schizophrenia in the Japanese population. However, since our meta-analysis results demonstrated strong support for association of rs1801133 with schizophrenia, further replication studies based on a gene-wide approach need to be considered.

Background Many studies including our previous ones as to PROKR2 and CLOCK have suggested that circadian genes may be involved in the mechanisms of mood disorders and their treatment responses. Also several recent investigations have reported that SIRT1 plays an important role in the circadian system as conventional circadian clock genes, and also have some relation to dopaminergic metabolism. So we considered the SIRT1 gene to be a good candidate gene for the pathophysiology for MDD and SSRI responses in MDD, and conducted a case–control study using four tagging SNPs (450 MDD patients, including 261 patients treated by SSRIs and 766 controls). Method The MDD patients in this study had scores of 12 or higher on the 17 items of the Structured Interview Guide for Hamilton Rating Scale for Depression (SIGH-D). We defined a clinical response as a decrease of more than 50% in baseline SIGH-D within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. Marker-trait association analysis was used to evaluate allele and genotype association with the chi-square test, and haplotype association analysis was evaluated with a likelihood ratio test. Result We found an association between rs10997875 in SIRT1 gene and MDD in the allele/genotype analysis. In addition, this significance of these associations survived Bonferroni correction. However, we did not find any association between SIRT1 gene and SSRI therapeutic response in MDD in the allele/genotype analysis or haplotype analysis. Limitations A replication study using larger samples may be required for conclusive results, since our sample size was small. Conclusions Our results suggest that rs10997875 in SIRT1 gene may play a role in the pathophysiology of MDD in the Japanese population.

Several evidence suggests that alterations in serotonin 6 (5-HT6) receptors might be associated with the pathophysiology of mood disorders. Therefore, to evaluate the association between HTR6 and BP and MDD, we conducted a case-control study of Japanese population samples (1007 BP patients, 447 MDD patients and 1753 controls) with five tagging SNPs, including rs1805054 (C267T), in HTR6. In addition, we conducted a meta-analysis of rs1805054, which has been examined in other studies. We selected five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997). Moreover, three association studies for BP and four association studies for MDD, including this study, met our criteria for the meta-analysis of rs1805054. We did not detect an association between tagging SNPs in HTR6 and BP and MDD in the allele/genotype, haplotype analysis or meta-analysis. In conclusion, we found no association involving polymorphism and mood disorder in the Japanese population. However, because changes in expression level or signal transduction of this receptor may be involved in the pathology of these diseases, it will be necessary to conduct the further study about the relationship between this receptor and mood disorders in the future.

The aim of the current study was to examine the association of KREMEN1 and DKK1, two wnt pathway-related genes with schizophrenia in Japanese subjects. We genotyped 16 common genetic variants within the aforementioned genes and examined their associations with schizophrenia. Results demonstrated that a common variant in the promoter region of KREMEN1 might modulate the risk of schizophrenia in the Japanese. However, further replication will be needed for conclusive interpretation of the effect of this locus on the pathogenesis of schizophrenia.