Schizophrenia and cognitive dysfunction.

Schizophrenia is a psychiatric disorder with cognitive dysfunction as a core symptom along with positive and negative symptoms. Cognitive dysfunction in schizophrenia can be broadly classified into neurocognitive and social cognitive deficits, with these deficits significantly influencing social functioning. Therapeutic interventions aiming to enhance neurocognition and social cognition have been developed.

An Exploratory Study of the Potential of Online Counseling for University Students by a Human-Operated Avatar Counselor.

Recently, the use of digital technologies, such as avatars and virtual reality, has been increasingly explored to address university students' mental health issues. However, there is limited research on the advantages and disadvantages of counselors using avatars in online video counseling. Herein, 25 university students were enrolled in a pilot online counseling session with a human counselor-controlled avatar, and asked about their emotional experiences and impressions of the avatar and to provide qualitative feedback on their communication experience.

Reliability and validation of the Japanese version of the cognitive distortion scale.

The cognitive distortion scale (CDS) is a self-rated measure to assess the degree of cognitive distortion which is 10 thinking errors commonly seen in depression. However, there is no scale to measure 10 types cognitive distortions specific to depression in Japan. Therefore, this study translated the CDS into Japanese (CDS-J), and examined its factor structure, validity, and reliability in a Japanese population.

Associations between negative and positive automatic thoughts and clinical variables in patients with schizophrenia.

This study investigated the relationships between negative and positive automatic thoughts and clinical variables in patients with schizophrenia. The participants included 36 patients with schizophrenia (male = 16; female = 20; age = 42.86 ± 9.

Effects of group therapy on jumping to conclusion bias in adolescents with autism spectrum disorder : An exploratory study.

Background And Purpose: Jumping to conclusion (JTC)-a cognitive bias in thinking processes-leads to drawing conclusions based on little information, and could be related to psychosis and paranoia. While it has recently been pointed out that it could accompany the autism spectrum disorder (ASD), no interventions targeting this bias in adolescents with ASD have been reported. Therefore, this exploratory study investigated the effects of a group social cognition program on JTC bias in adolescents with ASD.

Association between serum folate levels and schizophrenia based on sex.

Aim: Sex differences in serum folate concentrations are well known, but no studies have investigated the association between serum folate levels and schizophrenia based on sex. With this study in a Japanese population, we examined the difference in serum folate levels between patients with schizophrenia and non-psychiatric controls stratified by sex. The relations among serum folate levels, plasma total homocysteine (tHcy), and serum vitamin B6 (pyridoxal) levels were also examined using data from our previous studies.

Negative and positive self-thoughts predict subjective quality of life in people with schizophrenia.

Purpose: Recently, cognitive variables such as negative and positive self-belief and thoughts have attracted much attention because they are associated with functional outcomes and quality of life (QOL). However, it is unclear how cognitive variables affect subjective and objective QOL. This study aimed to investigate the relationship of negative and positive self-belief and thoughts with subjective and objective QOL.

Clozapine Pharmacogenetic Studies in Schizophrenia: Efficacy and Agranulocytosis.

Clozapine is an efficacious atypical antipsychotic for treatment-refractory schizophrenia. Clinical response and appearance of adverse events vary among individual patients receiving clozapine, with genetic and non-genetic factors potentially contributing to individual variabilities. Pharmacogenetic studies investigate associations between genetic variants and drug efficacy and toxicity.

Decreased serum pyridoxal levels in schizophrenia: meta-analysis and Mendelian randomization analysis.

Background: Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway.

Methods: We first conducted a case-control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort ( = 1276). Subsequently, we conducted a meta-analysis of association studies ( = 2125).

Elevated peripheral blood glutamate levels in major depressive disorder.

Purpose: There is growing evidence that glutamatergic signaling may be involved in major depressive disorder (MDD). In regard to peripheral blood glutamate changes in MDD, inconsistent findings have been reported. The purpose of the present study was to evaluate whether blood glutamate levels differed between MDD patients and control participants.

Retraction: A significant causal association between C-reactive protein levels and schizophrenia.

This retracts the article DOI: 10.1038/srep26105.

Decreased serum pyridoxal levels in schizophrenia: meta-analysis and Mendelian randomization analysis.

Background: Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway.

Methods: We first conducted a case-control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort ( = 1276). Subsequently, we conducted a meta-analysis of association studies ( = 2125).

Altered KYN/TRP, Gln/Glu, and Met/methionine sulfoxide ratios in the blood plasma of medication-free patients with major depressive disorder.

Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) is a comprehensive, quantitative, and high throughput tool used to analyze metabolite profiles. In the present study, we used CE-TOFMS to profile metabolites found in the blood plasma of 33 medication-free patients with major depressive disorder (MDD) and 33 non-psychiatric control subjects. We then investigated changes which occurred in the metabolite levels during an 8-week treatment period.

Effect of Clozapine on DNA Methylation in Peripheral Leukocytes from Patients with Treatment-Resistant Schizophrenia.

Clozapine is an atypical antipsychotic, that is established as the treatment of choice for treatment-resistant schizophrenia (SCZ). To date, no study investigating comprehensive DNA methylation changes in SCZ patients treated with chronic clozapine has been reported. The purpose of the present study is to reveal the effects of clozapine on DNA methylation in treatment-resistant SCZ.

Gene expression-based biological test for major depressive disorder: an advanced study.

Purpose: Recently, we could distinguished patients with major depressive disorder (MDD) from nonpsychiatric controls with high accuracy using a panel of five gene expression markers (, and ) in leukocyte. In the present study, we examined whether this biological test is able to discriminate patients with MDD from those without MDD, including those with schizophrenia and bipolar disorder.

Patients And Methods: We measured messenger ribonucleic acid expression levels of the aforementioned five genes in peripheral leukocytes in 17 patients with schizophrenia and 36 patients with bipolar disorder using quantitative real-time polymerase chain reaction (PCR), and we combined these expression data with our previous expression data of 25 patients with MDD and 25 controls.

Cumulative effect of the plasma total homocysteine-related genetic variants on schizophrenia risk.

Previous studies suggest that elevated total homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which correlates with plasma total homocysteine levels, are risk factors for schizophrenia (SCZ). Recently, a large genome-wide association study (GWAS) of plasma total homocysteine levels in individuals of European ancestry identified many single-nucleotide polymorphisms (SNPs) (n=13,974). The primary purpose of this study was to examine the association between these plasma total homocysteine-related SNPs and SCZ in the Japanese population.

1H-magnetic resonance spectroscopy study of glutamate-related abnormality in bipolar disorder.

Background: Previous studies of patients with bipolar disorder (BD) using magnetic resonance spectroscopy (MRS) have shown neurophysiological abnormalities related to the glutamate (Glu)-glutamine (Gln) cycle, membrane turnover, and neuronal integrity, although the results were neither consistent nor conclusive. Recently it has been reported the Gln/Glu ratio is the most useful index, quantifying neuronal-glial interactions and the balance of glutamatergic metabolites In this MRS study, we elucidated the abnormalities of metabolites in a larger sample of patients with BD with a high-field MRI system.

Methods: Sixty-two subjects (31 patients with BD and 31 healthy controls [HC]) underwent 3T proton MRS (1H-MRS) of the anterior cingulate cortex (ACC) and left basal ganglia (ltBG) using a stimulated echo acquisition mode (STEAM) sequence.

Calcium Signaling Pathway Is Associated with the Long-Term Clinical Response to Selective Serotonin Reuptake Inhibitors (SSRI) and SSRI with Antipsychotics in Patients with Obsessive-Compulsive Disorder.

Background: Selective serotonin reuptake inhibitors (SSRI) are established first-line pharmacological treatments for obsessive-compulsive disorder (OCD), while antipsychotics are used as an augmentation strategy for SSRI in OCD patients who have either no response or a partial response to SSRI treatment. The goal of the present study was to identify genetic variants and pathways that are associated with the long-term clinical response of OCD patients to SSRI or SSRI with antipsychotics.

Methods: We first performed a genome-wide association study of 96 OCD patients to examine genetic variants contributing to the response to SSRI or SSRI with antipsychotics.

A significant causal association between C-reactive protein levels and schizophrenia.

Many observational studies have shown elevated blood CRP levels in schizophrenia compared with controls, and one population-based prospective study has reported that elevated plasma CRP levels were associated with late- and very-late-onset schizophrenia. Furthermore, several clinical studies have reported the efficacy of anti-inflammatory drugs on the symptoms in patients with schizophrenia. However, whether elevated CRP levels are causally related to schizophrenia is not still established because of confounding factors and reverse causality.

No association between BDNF Val66Met polymorphism and treatment response in obsessive-compulsive disorder in the Japanese population.

Aim: Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, and it promotes the development and function of dopaminergic and serotonergic neurons. The Met allele of the BDNF Val66Met polymorphism is associated with a decrease in activity-dependent secretion of BDNF compared with the Val allele, and a number of studies have provided evidence for the association between this polymorphism and obsessive-compulsive disorder (OCD). The purpose of this study was to investigate whether this functional variant of the BDNF gene is associated with OCD and treatment response in patients with OCD in the Japanese population.

Association study of polymorphism in the serotonin transporter gene promoter, methylation profiles, and expression in patients with major depressive disorder.

The serotonin transporter (5HTT) may be associated with the pathogenesis of major depressive disorder (MDD). The 5HTT-linked polymorphic region (5HTTLPR) genotype may determine how levels of 5HTT mRNA are influenced by promoter methylation. We examined the association of 5HTT gene methylation, which influences gene expression, and the 5HTTLPR genotype before antidepressant treatment and expression before and after treatment.

Sex differences of leukocytes DNA methylation adjusted for estimated cellular proportions.

Background: DNA methylation, which is most frequently the transference of a methyl group to the 5-carbon position of the cytosine in a CpG dinucleotide, plays an important role in both normal development and diseases. To date, several genome-wide methylome studies have revealed sex-biased DNA methylation, yet no studies have investigated sex differences in DNA methylation by taking into account cellular heterogeneity. The aim of the present study was to investigate sex-biased DNA methylation on the autosomes in human blood by adjusting for estimated cellular proportions because cell-type proportions may vary by sex.

No association between the COMT Val158Met polymorphism and the long-term clinical response in obsessive-compulsive disorder in the Japanese population.

Objective: Catechol-O-methyltransferase (COMT) is an enzyme that participates in the metabolic inactivation of dopamine and norepinephrine, and the Met allele of the COMT Val158Met polymorphism is associated with lower enzymatic activity. The purpose of the present study was to investigate whether this functional variant is associated with obsessive-compulsive disorder (OCD) and the clinical responses in OCD.

Methods: We first performed a case-control association study between the COMT Val158Met polymorphism and OCD (171 cases and 944 controls).

Polymorphism in the promoter of the gene for the serotonin transporter affects the age of onset of major depressive disorder in the Japanese population.

Objective: Recent research has suggested that a functional polymorphism in the promoter region of the serotonin transporter gene (serotonin transporter-linked polymorphic region, 5HTTLPR) may be implicated in gene-environment interactions leading to major depressive disorder (MDD).

Methods: Our study examined the association between 5HTTLPR and clinical variables of MDD in the Japanese population. We genotyped 5HTTLPR in 216 patients with MDD and 213 age- and sex-matched controls.

Blood diagnostic biomarkers for major depressive disorder using multiplex DNA methylation profiles: discovery and validation.

Aberrant DNA methylation in the blood of patients with major depressive disorder (MDD) has been reported in several previous studies. However, no comprehensive studies using medication-free subjects with MDD have been conducted. Furthermore, the majority of these previous studies has been limited to the analysis of the CpG sites in CpG islands (CGIs) in the gene promoter regions.