Schizophrenia Spectrum Research Articles

Subjective Experience and Perceived Benefits in Clients with Schizophrenia Following Participation in Metacognition Reflection and Insight Therapy (MERIT).

Schizophrenia spectrum disorders involve disturbances in the experience of the self, which are related to limited metacognitive ability. The aim of metacognition-based therapies is to improve metacognitive ability and, subsequently, self-management and recovery. Adding to the quantitative findings from a trial on the effectiveness of Metacognition Reflection and Insight Therapy (MERIT), in the current study, we report on a qualitative assessment of MERIT's subjective perceived contribution. Twenty-seven patients with schizophrenia were interviewed after completing MERIT. Content analysis based on grounded theory was conducted by two independent raters. Most participants were satisfied with the therapy and reported improvement mainly in self-experience domains. The main contributors to perceived improvement pertained to the intervention process (e.g., therapeutic alliance and therapist interventions) as well as to the patient being an active agent of change. Perceived outcomes are particularly important among this cohort, as they often cope with limited metacognitive abilities, expressed by challenges in reflecting on themselves and others. The current study supports MERIT as a treatment that enhances positive outcomes for people with schizophrenia.

Effectiveness of video-based psychiatric rehabilitation for patients with early-phase schizophrenia spectrum: A randomized controlled trial.

This study aimed to establish a comprehensive set of recovery-oriented rehabilitation programs for individuals with schizophrenia, comparing the efficacy of video-based rehabilitation to traditional face-to-face interventions. The primary objective was to assess whether video-based rehabilitation could serve as a viable alternative for individuals with schizophrenia residing in remote areas. A randomized controlled study was used to recruit 80 patients with schizophrenia in a stable post-hospitalization stage following discharge. Participants were categorized into three groups: 24 in the control group, 21 in the face-to-face group, and 35 in the remote group. Assessment parameters included psychiatric symptoms, social skills, family function and self-stigma. A total of 68 participants completed the program. The findings indicated significant differences (p < .05) between the control group and intervention group, particularly in the Positive and Negative Syndrome Scale (PANSS) and the Personal and Social Performance Scale (PSP). The rehabilitation program, tailored for patients in the early phase of the schizophrenia spectrum, demonstrates both effectiveness and feasibility in enhancing clinical symptoms and social functions. Notably, interventions conducted via video proved to be equally effective as those administered face-to-face.

Transcriptomic sex differences in postmortem brain samples from patients with psychiatric disorders.

Many psychiatric disorders exhibit sex differences, but the underlying mechanisms remain poorly understood. We analyzed transcriptomics data from 2160 postmortem adult prefrontal cortex brain samples from the PsychENCODE consortium in a sex-stratified study design. We compared transcriptomics data of postmortem brain samples from patients with schizophrenia (SCZ), bipolar disorder (BD), and autism spectrum disorder (ASD) with transcriptomics data of postmortem control brains from individuals without a known history of psychiatric disease. We found that brain samples from females with SCZ, BD, and ASD showed a higher burden of transcriptomic dysfunction than did brain samples from males with these disorders. This observation was supported by the larger number of differentially expressed genes (DEGs) and a greater magnitude of gene expression changes observed in female versus male brain specimens. In addition, female patient brain samples showed greater overall connectivity dysfunction, defined by a higher proportion of gene coexpression modules with connectivity changes and higher connectivity burden, indicating a greater degree of gene coexpression variability. We identified several gene coexpression modules enriched in sex-biased DEGs and identified genes from a genome-wide association study that were involved in immune and synaptic functions across different brain cell types. We found a number of genes as hubs within these modules, including those encoding SCN2A, FGF14, and C3. Our results suggest that in the context of psychiatric diseases, males and females exhibit different degrees of transcriptomic dysfunction and implicate immune and synaptic-related pathways in these sex differences.

Structural and Functional Characteristics of the Dorsolateral Prefrontal Cortex in Schizophrenia Spectrum Disorders and Their Associations with Onset Age

Background: the dorsolateral prefrontal cortex (DLPFC) is one of the latest brain structures to mature during the ontogeny, and its structural and functional abnormalities play an important role in the pathogenesis of schizophrenia. As schizophrenia spectrum disorders usually start before the complete brain maturation and their earlier onset is coupled with worse prognosis, we suggested that earlier illness onset is related to more pronounced aberrations of the DLPFC. The aim of study was to analyze the associations of the onset age of schizophrenia spectrum disorders with structural and functional characteristics of the DLPFC that differentiated patients with schizophrenia spectrum disorders from healthy controls. Patients and methods: male patients with a diagnosis of schizophrenia spectrum disorders (n = 82) and healthy controls (n = 86) underwent structural MRI and functional resting-state fMRI. Cortical thickness and whole-brain functional connectivity of the DLPFC as well as local coherence and amplitude of low-frequency fluctuations of haemodynamic signal in the DLPFC were analyzed. Results: patients demonstrated a decreased gray matter thickness in the DLPFC bilaterally along with aberrant (predominantly decreased) functional connectivity of the DLPFC with other brain structures in each hemisphere. These measures were not associated with the age of illness onset. Conclusions: structural and functional abnormalities revealed in this study coincide with conventional view on the DLPFC as one of the key regions in schizophrenia spectrum disorders pathogenesis, however, these aberrations were not related to the age of psychosis onset. Possible interpretations of our results and limitations of the study are discussed in the article.

Cognitive Impairment in an Episode of Schizophrenia Spectrum Disorder.

Cognitive Impairment in an Episode of Schizophrenia Spectrum Disorder.

The Future-oriented Repetitive Thought (FoRT) scale: Validation in Chinese samples and application in the schizophrenia spectrum

BackgroundRepetitive thoughts are usually associated with psychopathology. The Future-oriented Repetitive Thought (FoRT) Scale is a measure designed to capture frequency of repetitive thought about positive and negative future events. However, the validity of the scale in Chinese population and its application in the schizophrenia spectrum have not been examined. MethodsThe current study aimed to examine the psychometric properties of the Chinese version of the FoRT scale and to apply it to the schizophrenia spectrum. In Study 1, three samples (total N = 1875) of university students were recruited for exploratory factor analysis, confirmatory factor analysis, and validity test, respectively. In Study 2, we identified subsamples with high schizotypal traits (N = 89) and low schizotypal traits (N = 89), and recruited 36 inpatients with schizophrenia and 41 matched healthy controls. ResultsThe three-factor (pessimistic repetitive future thinking, repetitive thinking about future goals, and positive indulging about the future) structure of the FoRT scale with one item deleted, fitted the Chinese samples. And the scale could distinguish patients with schizophrenia and individuals with high schizotypal traits from controls. ConclusionThese findings support that the Chinese version of the FoRT scale is a valid tool and provide evidence for the potential applications in the schizophrenia spectrum.

Evaluation of the Glymphatic System in Schizophrenia Spectrum Disorder Using Proton Magnetic Resonance Spectroscopy Measurement of Brain Macromolecule and Diffusion Tensor Image Analysis Along the Perivascular Space Index.

The glymphatic system (GS), a brain waste clearance pathway, is disrupted in various neurodegenerative and vascular diseases. As schizophrenia shares clinical characteristics with these conditions, we hypothesized GS disruptions in patients with schizophrenia spectrum disorder (SCZ-SD), reflected in increased brain macromolecule (MM) and decreased diffusion-tensor-image-analysis along the perivascular space (DTI-ALPS) index. Forty-seven healthy controls (HCs) and 103 patients with SCZ-SD were studied. Data included 135 proton magnetic resonance spectroscopy (1H-MRS) sets, 96 DTI sets, with 79 participants contributing both. MM levels were quantified in the dorsal-anterior cingulate cortex (dACC), dorsolateral prefrontal cortex, and dorsal caudate (point resolved spectroscopy, echo-time = 35ms). Diffusivities in the projection and association fibers near the lateral ventricle were measured to calculate DTI-ALPS indices. General linear models were performed, adjusting for age, sex, and smoking. Correlation analyses examined relationships with age, illness duration, and symptoms severity. MM levels were not different between patients and HCs. However, left, right, and bilateral DTI-ALPS indices were lower in patients compared with HCs (P < .001). In HCs, age was positively correlated with dACC MM and negatively correlated with left, right, and bilateral DTI-ALPS indices (P < .001). In patients, illness duration was positively correlated with dACC MM and negatively correlated with the right DTI-ALPS index (P < .05). In the entire population, dACC MM and DTI-ALPS indices showed an inverse correlation (P < .01). Our results suggest potential disruptions in the GS of patients with SCZ-SD. Improving brain's waste clearance may offer a potential therapeutic approach for patients with SCZ-SD.

Long-Term Course of Remission and Recovery in Psychotic Disorders.

Understanding prognosis is critical to anticipating public health needs and providing care to individuals with psychotic disorders. However, the long-term course of remission and recovery remains unclear. In this study, the most common trajectories of illness course are described for a cohort of individuals followed for 25 years since first admission for psychosis. Participants are from the Suffolk County Mental Health Project, an epidemiological study of first-admission psychosis. Data for the present study was collected from six follow-ups, with 311 individuals assessed at the 25-year follow-up. Common patterns of remission and recovery were assessed in the baseline cohort of 591 individuals and the subsample from the 25-year follow up. In the baseline cohort and the 25-year subsample, the most common trajectory for individuals with schizophrenia spectrum disorders was no remission and no recovery. Among individuals with other psychotic disorders, in both the baseline and 25-year cohorts, the modal pattern was one of intermittent remission and recovery. Individuals with other psychotic disorders were more likely to experience stable remission (15.1%) and stable recovery (21.1%), outcomes that were rare among individuals with schizophrenia spectrum disorders (0% and 0.6%, respectively). The modal longitudinal pattern for individuals with other psychoses is one of multiple transitions into and out of symptomatic and functional recovery. Engagement in a long-term health care plan may help individuals detect and respond to these changes. Sustained remission and recovery are rare among people with schizophrenia spectrum disorders. Efforts should be directed toward developing more effective treatments for this population.

Systematic review and meta-analysis of the visual mismatch negativity in schizophrenia.

Mismatch negativity (MMN) is an event-related potential component automatically elicited by events that violate predictions based on prior events. To elicit this component, researchers use stimulus repetition to induce predictions, and the MMN is obtained by subtracting the brain response to rare or unpredicted stimuli from that of frequent stimuli. Under the Predictive Processing framework, one increasingly popular interpretation of the mismatch response postulates that MMN represents a prediction error. In this context, the reduced MMN amplitude to auditory stimuli has been considered a potential biomarker of Schizophrenia, representing a reduced prediction error and the inability to update the mental model of the world based on the sensory signals. It is unclear, however, whether this amplitude reduction is specific for auditory events or if the visual MMN reveals a similar pattern in schizophrenia spectrum disorder. This review and meta-analysis aimed to summarise the available literature on the vMMN in schizophrenia. A systematic literature search resulted in 10 eligible studies that resulted in a combined effect size of g = -.63, CI [-.86, -.41], reflecting lower vMMN amplitudes in patients. These results are in line with the findings in the auditory domain. This component offers certain advantages, such as less susceptibility to overlap with components generated by attentional demands. Future studies should use vMMN to explore abnormalities in the Predictive Processing framework in different stages and groups of the SSD and increase the knowledge in the search for biomarkers in schizophrenia.

Patient Perspectives on AI-Driven Predictions of Schizophrenia Relapses: Understanding Concerns and Opportunities for Self-Care and Treatment.

Early detection and intervention for relapse is important in the treatment of schizophrenia spectrum disorders. Researchers have developed AI models to predict relapse from patient-contributed data like social media. However, these models face challenges, including misalignment with practice and ethical issues related to transparency, accountability, and potential harm. Furthermore, how patients who have recovered from schizophrenia view these AI models has been underexplored. To address this gap, we first conducted semi-structured interviews with 28 patients and reflexive thematic analysis, which revealed a disconnect between AI predictions and patient experience, and the importance of the social aspect of relapse detection. In response, we developed a prototype that used patients' Facebook data to predict relapse. Feedback from seven patients highlighted the potential for AI to foster collaboration between patients and their support systems, and to encourage self-reflection. Our work provides insights into human-AI interaction and suggests ways to empower people with schizophrenia.

Nurses’ and patients’ perceptions of physical health screening for patients with schizophrenia spectrum disorders: a qualitative study

BackgroundDespite worldwide concern about the poor physical health of patients with schizophrenia spectrum disorders (SSD), physical health screening rates are low. This study reports nurses’ and patients’ experiences of physical health screening among people with SSD using the Finnish Health Improvement Profile (HIP-F) and their ideas for implementation improvements.MethodsA qualitative exploratory study design with five group interviews with nurses (n = 15) and individual interviews with patients with SSD (n = 8) who had experience using the HIP-F in psychiatric outpatient clinics. Inductive content analysis was conducted.ResultsTwo main categories were identified. First, the characteristics of the HIP-F were divided into the subcategories of comprehensive nature, facilitating engagement, interpretation and rating of some items and duration of screening. Second, suggestions for the implementation of physical health screening consisted of two subcategories: improvements in screening and ideas for practice. Physical health screening was felt to increase the discussion and awareness of physical health and supported health promotion. The HIP-F was found to be a structured, comprehensive screening tool that included several items that were not otherwise assessed in clinical practice. The HIP-F was also considered to facilitate engagement by promoting collaboration in an interactive way. Despite this, most of the nurses found the HIP-F to be arduous and too time consuming, while patients found the HIP-F easy to use. Nurses found some items unclear and infeasible, while patients found all items feasible. Based on the nurses’ experiences, screening should be clear and easy to interpret, and condensation and revision of the HIP-F tool were suggested. The patients did not think that any improvements to the HIP-F were needed for implementation in clinical settings.ConclusionsPatients with schizophrenia spectrum disorders are willing to participate in physical health screening. Physical health screening should be clear, easy to use and relatively quick. With this detailed knowledge of perceptions of screening, further research is needed to understand what factors affect the fidelity of implementing physical health screening in clinical mental health practice and to gain an overall understanding on how to improve such implementation.

Mentalization-based approach for schizophrenia spectrum disorders: a psychotherapeutic proposal for evolved schizophrenic trajectories and serious mental disorders.

There is a growing interest in psychotherapeutic approaches to pre-psychotic high-risk states or first-episode psychosis, where mentalization-based treatment has shown its utility. This article presents a mentalization-based approach for the treatment of those individuals diagnosed with an evolved schizophrenia spectrum disorder, whose characteristics make them especially inaccessible to reflective psychotherapeutic treatment. A synthesis of the conceptual frameworks that justify the needs for technical modification of the mentalization-based treatment foundational techniques is carried out, followed by the proposal of adaptations, with a focus in self-agency and patient-therapist dyad. Therapeutic interventions are outlined, including illustrative examples. The mentalizing approach presented here holds promise for future research and treatment opportunities for patients with evolved schizophrenia and other serious mental disorders.

Capgras syndrome in children and adolescents: A systematic review

ObjectivesTo improve understanding of Capgras syndrome (CS) in the pediatric population, this study investigates its clinical features and discerns similarities and differences compared to CS in adults. MethodsWe conducted a descriptive systematic review of case reports following PRISMA guidelines, including cases of pediatric patients with CS. Patient demographics, medical and psychiatric history, imposter identity, underlying diagnosis, clinical manifestation, treatments, and outcomes were extracted and analyzed. ResultsWe included 37 articles comprising 38 cases. The median age of patients was 15, with 23 (60.5%) being male. The most prevalent underlying diagnoses were schizophrenia spectrum and other psychotic disorders (47.3%). Imposter identity involved parents in 32 cases (84.2%). Associated symptoms included persecutory delusions (63.1%), auditory hallucinations (42.1%), aggression (31.5%), and depression (21.0%). ConclusionThere is a significant gap in our understanding of CS, particularly in pediatric patients. This is the first systematic review of CS in pediatric patients, encompassing all cases found in English literature since 1923.

Excessive left anterior hippocampal and caudate activation in schizophrenia underlie cognitive underperformance in a virtual navigation task

We used a virtual navigation paradigm in a city environment to assess neuroanatomical correlates of cognitive deficits in schizophrenia spectrum disorders (SSD). We studied a total of N = 36 subjects: 18 with SSD and 18 matched unaffected controls. Participants completed 10 rapid, single-trial navigation tasks within the virtual city while undergoing functional magnetic resonance imaging (fMRI). All trials tested ability to find different targets seen earlier, during the passive viewing of a path around different city blocks. SSD patients had difficulty finding previously-encountered targets, were less likely to find novel shortcuts to targets, and more likely to attempt retracing of the path observed during passive viewing. Based on a priori region-of-interest analyses, SSD participants had hyperactivation of the left hippocampus when passively viewing turns, hyperactivation of the left caudate when finding targets, and hypoactivation of a focal area of the dorsolateral prefrontal cortex when targets were initially shown during passive viewing. We propose that these brain-behaviour relations may bias or reinforce stimulus-response navigation approaches in SSD and underlie impaired performance when allocentric spatial memory is required, such as when forming efficient shortcuts. This pattern may extend to more general cognitive impairments in SSD that could be used to design remediation strategies.

Delusions and Delinquencies: A Comparison of Violent and Non-Violent Offenders With Schizophrenia Spectrum Disorders.

The relationship between schizophrenia spectrum disorders (SSD) and violent offending has long been the subject of research. The present study attempts to identify the content of delusions, an understudied factor in this regard, that differentiates between violent and non-violent offenses. Limitations, clinical relevance, and future directions are discussed. Employing a retrospective study design, machine learning algorithms and a comprehensive set of variables were applied to a sample of 366 offenders with a schizophrenia spectrum disorder in a Swiss forensic psychiatry department. Taking into account the different contents and affects associated with delusions, eight variables were identified as having an impact on discriminating between violent and non-violent offenses with an AUC of 0.68, a sensitivity of 30.8%, and a specificity of 91.9%, suggesting that the variables found are useful for discriminating between violent and non-violent offenses. Delusions of grandiosity, delusional police and/or army pursuit, delusional perceived physical and/or mental injury, and delusions of control or passivity were more predictive of non-violent offenses, while delusions with aggressive content or delusions associated with the emotions of anger, distress, or agitation were more frequently associated with violent offenses. Our findings extend and confirm current research on the content of delusions in patients with SSD. In particular, we found that the symptoms of threat/control override (TCO) do not directly lead to violent behavior but are mediated by other variables such as anger. Notably, delusions traditionally seen as symptoms of TCO, appear to have a protective value against violent behavior. These findings will hopefully help to reduce the stigma commonly and erroneously associated with mental illness, while supporting the development of effective therapeutic approaches.

D-serine and D-amino acid oxidase levels in patients with schizophrenia spectrum disorders in the first episode and 6-month follow-up

BackgroundD-serine and the D-amino acid oxidase (DAO) enzyme, which breaks down d-amino acids, may be involved in the pathophysiology of schizophrenia by affecting the N-methyl-D-aspartate (NMDA) receptor. The exact role of D-serine and DAO, as well as the consequences of increased DAO activity in patients with schizophrenia, remain unclear. We aimed to investigate D-serine and DAO levels in patients with first-episode schizophrenia spectrum disorders before treatment and after six months of treatment. MethodComparisons for the serum levels of D-serine and DAO were made between 81 healthy controls and 89 patients with first-episode schizophrenia spectrum disorders without a history of treatment. Further comparisons were made after 6 months for changes in these levels in the 41 patients in follow-up. The Positive and Negative Syndrome Scale (PANNS), Calgary Scale for Depression in Schizophrenia (CDSS), Montreal Cognitive Assessment Scale (MoCA), Global Assessment Scale (GAS), and Clinical Global Impression Scale (CGI) were used to evaluate the symptom severity and functionality. Secondary results included comparisons related to antipsychotic equivalent doses. ResultsBefore treatment, patients had significantly lower levels of D-serine, DAO, and D-serine/DAO ratio compared to healthy individuals (p < 0.001; p < 0.001; p = 0.004). DAO and D-serine levels of the patients were higher after six months of treatment (p = 0.025; p = 0.001). There was correlation of DAO levels with antipsychotic dosage and with PANSS negative and total subscale scores (rho = 0.421, p = 0.01; rho = 0.280, p = 0.008; rho = 0.371, p = 0.000). No correlation was found between serum D-serine level, DAO level, and the D-serine/DAO ratio with cognitive function. ConclusionsThe results suggest that D-serine and DAO may play a role that is sensitive to treatment effects in schizophrenia spectrum disorders. To gain a more comprehensive understanding of the impact antipsychotic drugs have on NMDA receptor dysfunction, there is a requirement for studies that directly evaluates the activity of the DAO enzyme.

Aberrant salience mediates the interplay between emotional abuse and positive symptoms in schizophrenia

IntroductionChildhood trauma and adversities (CTA) and aberrant salience (AS) have a pivotal role in schizophrenia development, but their interplay with psychotic symptoms remains vague. We explored the mediation performed by AS between CTA and psychotic symptomatology in schizophrenia. MethodsWe approached 241 adults suffering from schizophrenia spectrum disorders (SSDs), who have been in the unit for at least 12 consecutive months, excluding the diagnosis of dementia, and recent substance abuse disorder, and cross-sectional evaluated through the Aberrant Salience Inventory (ASI), Childhood Trauma Questionnaire Short-Form (CTQ-SF), and Positive and Negative Symptom Scale (PANSS). We tested a path-diagram where AS mediated the relationship between CTA and psychosis, after verifying each measure one-dimensionality through confirmatory factor analysis. ResultsThe final sample comprised 222 patients (36.9% female), with a mean age of 42.4 (± 13.3) years and an average antipsychotic dose of 453.6 (± 184.2) mg/day (chlorpromazine equivalents). The mean duration of untreated psychosis was 1.8 (± 2.0) years while the mean onset age was 23.9 (± 8.2) years. Significant paths were found from emotional abuse to ASI total score (β = 0.39; p < .001) and from ASI total score to PANSS positive (β = 0.17; p = .019). Finally, a statistically significant indirect association was found from emotional abuse to PANSS positive mediated by ASI total score (β = 0.06; p = .041; CI 95% [0.01, 0.13]). ConclusionEmotional abuse has an AS-mediated effect on positive psychotic symptomatology. AS evaluation could allow a better characterization of psychosis as well as explain the presence of positive symptoms in adults with SSDs who experienced CTA.

Early Maladaptive Schemas and Depression in Caregivers of Individuals With Schizophrenia Spectrum and Bipolar Disorders.

Early maladaptive schemas represent unhelpful frameworks of cognitions, emotions and subsequent behavioural responses and can be associated with depressive symptoms. Caregivers of individuals with serious mental illness (SMI) frequently report experiencing depressive symptoms. It is unclear whether depressive symptoms in caregivers are influenced by schemas. We aimed to compare activated schemas in caregivers of people with schizophrenia spectrum (SSD) and bipolar disorder (BD) diagnoses and to determine whether they were differentially related to depressive symptoms. Caregivers completed validated measures of depression and schemas. Independent samples t-tests and multivariate generalised linear models were used to assess differences in schemas and depressive symptoms between caregiver groups. Interrelationships between schema domains and caregiver depressive symptoms were delineated using correlational analyses and forward stepwise regressions. One hundred eight caregivers participated in the study (SSD n = 68, BD n = 40). No differences in depressive symptom severity or activated schemas were observed between caregiver groups. All schemas were significantly associated with depressive symptoms, and the Disconnection-Rejection schema domain explained the most variance in depressive symptoms in both caregiver groups. Schemas contribute to the severity of caregiver depression regardless of whether the person receiving care is diagnosed with SSD or BD. Schema therapeutic frameworks may be beneficial for use with caregivers to address schemas within the Disconnection-Rejection domain and alleviate depressive symptoms by reducing experiences of social isolation and alienation.

379. Multivariate Transdiagnostic Neural Biomarkers of Schizophrenia and Autism Spectrum Disorders During the Empathic Accuracy Task

379. Multivariate Transdiagnostic Neural Biomarkers of Schizophrenia and Autism Spectrum Disorders During the Empathic Accuracy Task

Study of the genetic association between selected 3q29 region genes and schizophrenia and autism spectrum disorder in the Japanese population.

Psychiatric disorders are highly inheritable, and most psychiatric disorders exhibit genetic overlap. Recent studies associated the 3q29 recurrent deletion with schizophrenia (SCZ) and autism spectrum disorder (ASD). In this study, we investigated the association of genes in the 3q29 region with SCZ and ASD. TM4SF19 and PAK2 were chosen as candidate genes for this study based on evidence from previous research. We sequenced TM4SF19 and PAK2 in 437 SCZ cases, 187 ASD cases and 524 controls in the Japanese population. Through targeted sequencing, we identified 6 missense variants among the cases (ASD & SCZ), 3 missense variants among controls, and 1 variant common to both cases and controls; however, no loss-of-function variants were identified. Fisher's exact test showed a significant association of variants in TM4SF19 among cases (p=0.0160). These results suggest TM4SF19 variants affect the etiology of SCZ and ASD in the Japanese population. Further research examining 3q29 region genes and their association with SCZ and ASD is thus needed.