Schizophrenia

MicroRNA dysregulation in glutamate and dopamine pathways of schizophrenia: From molecular pathways to diagnostic and therapeutic approaches

Schizophrenia is a complex psychiatric disorder, and genetic and environmental factors have been implicated in its development. Dysregulated glutamatergic and dopaminergic transmission pathways are involved in schizophrenia development. Besides genetic mutations, epigenetic dysregulation has a considerable role in dysregulating molecular pathways involved in schizophrenia. MicroRNAs (miRNAs) are small, non-coding RNAs that target specific mRNAs and inhibit their translation into proteins. As epigenetic factors, miRNAs regulate many genes involved in glutamate and dopamine signaling pathways; thereby, their dysregulation can contribute to the development of schizophrenia. Secretion of specific miRNAs from damaged cells into body fluids can make them one of the ideal non-invasive biomarkers in the early diagnosis of schizophrenia. Also, understanding the molecular mechanisms of miRNAs in schizophrenia pathogenesis can pave the way for developing novel treatments for patients with schizophrenia. In this study, we reviewed the glutamatergic and dopaminergic pathophysiology and highlighted the role of miRNA dysregulation in schizophrenia development. Besides, we shed light on the significance of circulating miRNAs for schizophrenia diagnosis and the recent findings on the miRNA-based treatment for schizophrenia.

Association between the copy number variations of Methyl-CpG binding domain family and schizophrenia

Schizophrenia is recognized as one of the most severe psychiatric disorders, with its pathogenesis likely involving genetic, epigenetic, developmental, and environmental factors. Members of the Methyl-CpG Binding Domain (MBD) Family play a crucial role in the regulation of genomic DNA methylation, and studies have implicated the association between MBD family and neurodevelopmental disorders. Copy number variations (CNVs) are a significant genetic basis for human genomic variation, also playing a critical role in the genetic processes of schizophrenia. Therefore, we aimed to evaluate the susceptibility of MBD family CNVs to schizophrenia by exploring and validating them in two separate populations using CNVplex™ and qPCR methods, and to explore the relationship between MBD family CNVs and clinical phenotypes in the overall population using chi-square tests and Fisher's exact tests. Results suggest that an increase in MBD1 gene copy number and a deficiency in MBD2 gene copy number may be associated with the risk of schizophrenia. The deficiency in MBD2 gene copy number may increase the risk of delusion of reference and delusion of persecutory in the overall sample, as well as in males. This research provides preliminary evidence supporting the association between MBD family CNVs and schizophrenia, highlighting the potential role of the MBD family in the pathogenesis of schizophrenia.

Evaluation of the content and quality of schizophrenia on TikTok: a cross-sectional study

Schizophrenia is a common and serious heterogeneous mental disorder that has a significant health and economic impact on families and society. As the prevalence of schizophrenia increases each year, public awareness of the disorder is growing. However, it remains unclear whether the quality of information presented in these videos is satisfactory. Therefore, a comprehensive assessment of the quality and content of schizophrenia-related videos on video-sharing platforms is necessary. We screened 123 schizophrenia-related videos from the video-sharing platform TikTok that met the criteria, and evaluated and analyzed them. First, the basic information provided in the videos was recorded and analyzed. The source and content type of each video was then determined. The educational content and quality of all videos were then evaluated using three rating instruments, Modified DISCERN, Global Quality Scale, and Journal of the American Medical Association (JAMA). Videos from different sources were also compared to see if they were statistically different in terms of educational content and quality. We identified 4 categories of content for the videos. The science introduction category had the largest number of 50, and the least number of videos was etiology and causation at 15. Six categories of sources of videos were also identified: the for-profit organizations category has the lowest number of 10, the health professionals category has the highest number of 45. There was a significant correlation between video source and duration (P = 0.014). The JAMA score was significantly positively correlated with the number of video likes (r = 0.721, P < 0.001). This study evaluated the content and information quality of 123 videos related to schizophrenia on the video-sharing platform TikTok. The findings indicate that while these videos offer some valuable insights into schizophrenia, the overall quality falls short of satisfactory levels, with inadequate reliability and accuracy.

Abnormal trial-to-trial variability in P300 time-varying directed eeg network of schizophrenia

Cognitive disturbance in identifying, processing, and responding to salient or novel stimuli are typical attributes of schizophrenia (SCH), and P300 has been proven to serve as a reliable psychosis endophenotype. The instability of neural processing across trials, i.e., trial-to-trial variability (TTV), is getting increasing attention in uncovering how the SCH "noisy" brain organizes during cognition processes. Nevertheless, the TTV in the brain network remains unrevealed, notably how it varies in different task stages. In this study, resorting to the time-varying directed electroencephalogram (EEG) network, we investigated the time-resolved TTV of the functional organizations subserving the evoking of P300. Results revealed anomalous TTV in time-varying networks across the delta, theta, alpha, beta1, and beta2 bands of SCH. The TTV of cross-band time-varying network properties can efficiently recognize SCH (accuracy: 83.39%, sensitivity: 89.22%, and specificity: 74.55%) and evaluate the psychiatric symptoms (i.e., Hamilton's depression scale-24, r = 0.430, p = 0.022, RMSE = 4.891; Hamilton's anxiety scale-14, r = 0.377, p = 0.048, RMSE = 4.575). Our study brings new insights into probing the time-resolved functional organization of the brain, and TTV in time-varying networks may provide a powerful tool for mining the substrates accounting for SCH and diagnostic evaluation of SCH.

"No one will come and help me make my life": Ecological-transactional model approach to resilience among people with a history of childhood adversity

Resilience refers to the ability to employ a collection of protective factors to return to or maintain positive mental health following an experience of disadvantage or adversity. Understanding why some children do well despite early adverse experiences is crucial because it can inform more effective policies and programs that help more children reach their full potential. This study aimed to explore and explain the development of resilience within an ecological-transactional framework. A qualitative case study approach was used recruiting participants with history of childhood adversity: six patients with a diagnosis of first-episode psychosis from the main referral psychiatric hospital in Kenya and eight healthy controls from a neighbouring community in Nairobi. The findings indicate that children and their contexts mutually influenced each other. Using the systemic perspective of the ecological-transactional model, our participants identified the home environment (microsystem) as an important enabler of trauma to children. Available social support at both the micro-and exosystem levels, including good caregiver-child relationships, acted as buffers to alleviate the negative influence of adversity, leading to successful adaptation. Our study highlights the significant impact of adversities during childhood and adolescence. In addition, it emphasizes the influence of multiple contexts, supporting the need for appropriate interventions at each level to mitigate the negative consequences.

Aberrant activity at rest of the associative striatum in schizophrenia: Meta-analyses of the amplitude of low frequency fluctuations

Schizophrenia is a severe psychiatric disorder associated with brain alterations at rest. Amplitude of low-frequency fluctuations (ALFF) and its fractional version (fALFF) have been widely used to investigate alterations in spontaneous brain activity in schizophrenia. However, results are still inconsistent. Furthermore, while these measurements are similar, they showed some differences, and no meta-analysis has been yet performed to compare them in schizophrenia. Thus, we conducted systematic research in five databases and in the grey literature to find articles investigating fALFF and/or ALFF alterations in schizophrenia. Two separate meta-analyses were performed using the SDM-PSI software to identify fALFF and ALFF alterations separately. Then, a conjunction analysis was conducted to determine congruent results between the two approaches. We found that patients with schizophrenia showed altered fALFF activity in the left insula/putamen, the right paracentral lobule and the left middle occipital gyrus compared to healthy individuals. Patients with schizophrenia exhibited ALFF alterations in the bilateral putamen, the bilateral caudate nucleus, the bilateral inferior frontal gyrus, the right precuneus, the right precentral gyrus, the left postcentral gyrus, the right posterior cingulate gyrus, compared to healthy controls. ALFF increased activity in the left putamen was higher in drug-naïve patients and was correlated with positive symptoms. The conjunction analysis revealed a spatial convergence between fALFF and ALFF studies in the left putamen. This left putamen cluster is part of the associative striatum. Its alteration in schizophrenia provides additional support to the influential aberrant salience hypothesis of psychosis.

Comparison of sociodemographic, clinical, and alexithymia characteristics of schizophrenia patients with and without criminal records

The primary objective of our study is to delineate differences between individuals diagnosed with schizophrenia who have a criminal record and those diagnosed with schizophrenia without a criminal record in terms of sociodemographic and clinical characteristics, levels of intelligence and insight, alexithymia, psychological symptoms, aggression, and impulsivity violence. In doing so, we aim to determine whether these findings serve as predictive indicators in the commission and prediction of criminally relevant actions in individuals diagnosed with schizophrenia. This study was conducted with patients aged 18-65 who were diagnosed with 'schizophrenia' according to DSM-5 diagnostic criteria and received outpatient follow-up and treatment. Our study consists of a total of 100 individuals diagnosed with schizophrenia, with 50 having a criminal record and 50 without. The results of the study demonstrated statistically significant differences between the forensic case and control groups in terms of gender, marital status, and educational status. Additionally, it was determined that there was a significant difference in the difficulty describing feelings between the forensic case and control groups. Statistically significant differences were obtained between the two groups in terms of BPAQ total score, the physical aggression subscale, and the anger subscale scores. There was also a statistically significant difference in terms of the BIS-11-SF total score, attention impulsivity, motor impulsivity, and non-planning subscales. Regression analysis indicated that gender, marital status, educational status, age of illness onset, difficulty in verbalizing emotions, overall aggression level, physical aggression, anger, overall impulsivity level, attention impulsivity, motor impulsivity, and inability to plan were associated with forensic behaviors in patients with schizophrenia. As a result, there is a need for studies that encompass larger and more diverse sample groups and patients from different regions. Additionally, these studies should incorporate scales and methods that comprehensively analyze both positive and negative symptoms.

EPO Deficiency Upregulates GADD45b/p38 MAPK Axis, Mediating Schizophrenia-Related Synaptic and Cognitive Impairments

Schizophrenia (SZ) is a chronic and severe mental illness associated with psychiatric symptoms, cognitive deficits, and social dysfunction. Current clinical interventions only limit relief of psychiatric symptoms and have minimal impact on cognitive impairments. Erythropoietin (EPO), known for its role in neurogenesis and synaptic plasticity, is significantly low in SZ patients. However, the role of EPO deficiency in SZ-associated cognitive deficits remains unclear. In this study, we used the MK801-induced SZ rat model to show that EPO levels were significantly decreased, correlating with cognitive impairments. EPO supplementation mitigated apoptosis, synaptic damage, and cognitive impairments caused by MK801. RNA-sequencing and Western blot analysis revealed increased expression of growth arrest and DNA damage 45b (GADD45b) in MK801-treated rats, reversed by EPO supplementation. Moreover, overexpression of GADD45b exacerbated neuronal loss and cognitive impairments in male Sprague-Dawley rats, while downregulation of GADD45b rescued these SZ-related pathologies. Notably, the benefits of EPO supplementation on SZ pathology were blocked by GADD45b overexpression. Inhibition of p38 MAPK, a GADD45b target, reduced MK801-induced apoptosis and synaptic damage. These findings uncover a novel etiopathogenic mechanism of SZ-related cognitive impairments, driven by EPO deficiency and the activation of the GADD45b/p38 MAPK axis.

Association between small intestine bacterial overgrowth and psychiatric disorders

Small intestinal bacterial overgrowth (SIBO) is a gastrointestinal condition characterized by abnormal colonization of bacteria in the small intestine, leading to overgrowth and alteration, which is linked to gastrointestinal issues, potentially affecting neurological and mental health. Despite existing research, we still do not understand how SIBO affects tryptophan metabolism and psychiatric diseases. We investigated the literature for connections between SIBO, tryptophan metabolism disruptions, and psychiatric disorders like autism, schizophrenia, Alzheimer's, and Parkinson's diseases. We also explored the interaction between thyroid disorders and their influence on SIBO and psychiatric illnesses. PubMed and Google Scholar databases were searched using keywords and phrases, individual and in combinations, like "SIBO," "gut microbiota," "neurologic disorders," "mental disorders," "tryptophan," "dopamine," and "thyroid disease." We focused on original research and review papers that presented empirical studies conducted on animal models and human subjects published in English between February 1992 to February 2023. The initial 2 634 534 records were preliminary screened based on title and abstract and then subjected to full-text review to exclude publications with insufficient data on SIBO, lack of a psychiatric disorder component, or methodological limitations compromising the integrity of the findings. The analysis highlights the significance of the association between psychiatric disorders and SIBO, emphasizing the role of gut-microbial diversity in mental health. We advocate for more detailed studies, including longitudinal research, to clarify the causal relationships between SIBO, gut dysbiosis, and psychiatric disorders and for an integrated approach while treating complex psychiatric conditions.

Mechanisms of glutamate receptors hypofunction dependent synaptic transmission impairment in the hippocampus of schizophrenia susceptibility gene Opcml-deficient mouse model

Schizophrenia is a severe psychiatric disorder with high heritability, characterized by positive and negative symptoms as well as cognitive abnormalities. Dysfunction in glutamate synapse is strongly implicated in the pathophysiology of schizophrenia. However, the precise role of the perturbed glutamatergic system in contributing to the cognitive abnormalities of schizophrenia at the synaptic level remains largely unknown. Although our previous work found that Opcml promotes spine maturation and Opcml-deficient mice exhibit schizophrenia-related cognitive impairments, the synaptic mechanism remains unclear. By using whole-cell patch clamp recording, we found that decreased neuronal excitability and alterations in intrinsic membrane properties of CA1 PNs in Opcml-deficient mice. Furthermore, Opcml deficiency leads to impaired glutamatergic transmission in hippocampus, which is closely related to postsynaptic AMPA/NMDA receptors dysfunction, resulting in the disturbances of E/I balance. Additionally, we found that the aripiprazole which we used to ameliorate abnormal cognitive behaviors also rescued the impaired glutamatergic transmission in Opcml-deficient mice. These findings will help to understand the synaptic mechanism in schizophrenia pathogenesis, providing insights into schizophrenia therapeutics with glutamatergic disruption.

Factors associated with caregiver burden among family members of persons with schizophrenia in urban communities of China

OBJECTIVE

Family caregivers bear a heavy burden while providing care for those with schizophrenia, and they frequently play an important role in this regard. The present study examined the degree of caregiver burden and characteristics related to it among family caregivers of persons with schizophrenia in Chinese urban settings.

METHODS

Between August 2023 and June 2024, a cross-sectional study was conducted of 401 family caregivers of persons with schizophrenia living in metropolitan settings. The following measures were administered: the Zarit Burden interview (ZBI), General Self-Efficacy Scale (GSES), Social Support Rating Scale (SSRS), and Simplified Coping Style Questionnaire (SCSQ). Linear regression analyses were used to identify independent correlates of caregiver burden.

RESULTS

Family caregivers of persons with schizophrenia had an average ZBI score of 32.90(SD = 17.53) on a 0-88 scale, with the majority (80.0%) reporting moderate caregiver burden (scores of 21-39). The person with schizophrenia's marital status (not married), impulsive or aggressive conduct in the previous year, the caregiver's physical health (poor), and not having multiple caregivers were all independent correlates of caregiver burden.

CONCLUSIONS

Family caregivers of persons with schizophrenia experience a moderate level of caregiver burden. To lessen the psychological suffering of and strain on caregivers, it is important to intervene early on impulsive and aggressive conduct of persons with schizophrenia, effectively treat physical health problems of caregivers, and strengthen the social support system or otherwise provide assistance to those caring for persons with schizophrenia.

Toxoplasma gondii infection is associated with schizophrenia from the perspectives of seroepidemiology and serum metabolomics in Hunan Province, China

Toxoplasma gondii (T.gondii) can influence the host's neurotransmission, central immune responses, and brain structure, potentially impacting the onset and development of various psychiatric disorders such as schizophrenia. We employed Electrochemiluminescence Immunoassay (ECLIA) to measure anti-Toxoplasma antibodies in 451 schizophrenic patients and 478 individuals from the general population in Hunan, China. The incidence rate of T.gondii infection in schizophrenic patients (8.87 %) was higher than that in the general population (3.77 %). A significant difference was observed among females, but not in males. Age-stratified analysis revealed significant differences in the 21-40 and 41-60 age groups. The two populations had no significant difference in the antibody titer for T. gondii infection. Additionally, the profile of circulating metabolites in the serum of schizophrenic patients with or without T. gondii infection was examined using non-targeted metabolomics assay. A total of 68 metabolites were differentially expressed between Toxoplasma-positive and Toxoplasma-negative groups, potentially mediating the connection between T. gondii infection and schizophrenia. Our research suggests that schizophrenic patients are susceptible to T. gondii infection with distinct metabolic program.

Deciphering the interplay between psychopathological symptoms, sensorimotor, cognitive and global functioning: a transdiagnostic network analysis

BACKGROUND

Understanding the relationship between psychopathology and major domains of human neurobehavioral functioning may identify new transdiagnostic treatment targets. However, studies examining the interrelationship between psychopathological symptoms, sensorimotor, cognitive, and global functioning in a transdiagnostic sample are lacking. We hypothesized a close relationship between sensorimotor and cognitive functioning in a transdiagnostic patient sample.

METHODS

We applied network analysis and community detection methods to examine the interplay and centrality [expected influence (EI) and strength] between psychopathological symptoms, sensorimotor, cognitive, and global functioning in a transdiagnostic sample consisting of 174 schizophrenia spectrum (SSD) and 38 mood disorder (MOD) patients. All patients (n = 212) were examined with the Positive and Negative Syndrome Scale (PANSS), the Heidelberg Neurological Soft Signs Scale (NSS), the Global Assessment of Functioning (GAF), and the Brief Cognitive Assessment Tool for Schizophrenia consisted of trail making test B (TMT-B), category fluency (CF) and digit symbol substitution test (DSST).

RESULTS

NSS showed closer connections with TMT-B, CF, and DSST than with GAF and PANSS. DSST, PANSS general, and NSS motor coordination scores showed the highest EI. Sensory integration, DSST, and CF showed the highest strength.

CONCLUSIONS

The close connection between sensorimotor and cognitive impairment as well as the high centrality of sensorimotor symptoms suggests that both domains share aspects of SSD and MOD pathophysiology. But, because the majority of the study population was diagnosed with SSD, the question as to whether sensorimotor symptoms are really a transdiagnostic therapeutic target needs to be examined in future studies including more balanced diagnostic groups.

Burdening caregivers of patients with schizophrenia at Edward Francis Small Teaching Hospital, The Gambia

PURPOSE

Deinstitutionalization of persons living with mental illness has led to many patients residing in communities with family members and shifting the burden of care and caregiving from hospitals to homes. The aim of the study was to determine the burden on caregivers of patients with schizophrenia at Edward Francis Small Teaching Hospital (EFSTH).

METHODS

This was a descriptive cross-sectional study design with a sample consisting of 161 randomly selected caregivers of patients with schizophrenia. The GHQ-12 questionnaire was used to determine the general health status of the caregivers. The caregivers' burden was assessed using the Zarit Burden Scale. The data were collected using the researcher-administered method. The collected data were analyzed with IBM SPSS Version 20 using descriptive statistics, mean differences, and the general linear model (GLM).

RESULTS

The main findings of this study were that caregivers experienced a significantly high level of burden. Most of them experienced high levels of physical (70%), psychological (93.2%), social (78.3%) and financial (55.3%) burdens. Employment status, specifically unemployment status and belonging to the Wolof ethnic group, was a significant predictor of the level of financial burden on the caregivers. Similarly, the total score for social burden was also significantly greater among unemployed caregivers. Educational level was a significant predictor of the total score on the psychological and physical burden scale.

CONCLUSION

The caregivers of patients with schizophrenia at EFSTH are experiencing a high level of burden as a result of their caregiving role, which affects their health, and this calls for urgent intervention.

Sex difference alters the behavioral and cognitive performance in a rat model of schizophrenia induced by sub-chronic ketamine

Schizophrenia is a complex neuropsychiatric disorder with positive, negative, and cognitive symptoms. In rats, sub-chronic administration of ketamine is used for the induction of schizophrenia model. Increased locomotor activity is one of the most important features of psychotic-like symptoms in rodents. On the other hand, risperidone is a potent antipsychotic medication that is approved for the treatment of schizophrenia and bipolar disorder. In the present research, we aimed to investigate the effect of sub-chronic treatment of ketamine on cognitive and behavioral functions, and brain-derived neurotrophic factor (BDNF) expression level in the prefrontal cortex. Also, we assessed the efficacy of risperidone on cognitive and behavioral impairments induced by ketamine. Possible sex differences were also measured. Ketamine was intraperitoneally injected at the dose of 30 mg/kg for five consecutive days. Risperidone was also intraperitoneally injected at the dose of 2 mg/kg. Novel object recognition memory, pain threshold, locomotor activity, rearing behavior, and BDNF level were evaluated. The results showed that ketamine injection for five consecutive days impaired the acquisition of long-term recognition memory and decreased BDNF level in the prefrontal cortex in both sexes. Also, it decreased pain threshold in females, increased rearing behavior in males, and induced hyperlocomotion with greater effect in females. On the other hand, risperidone restored or attenuated the effect of ketamine on all the behavioral effects and BDNF level. In conclusion, we suggested that there were sex differences in the effects of ketamine on pain perception, locomotion, and rearing behavior in a rat model of schizophrenia.

The dimensional structure of the Positive and Negative Syndrome Scale in first-episode schizophrenia spectrum disorders: an Exploratory Graph Analysis from the OPTiMiSE trial

The Positive and Negative Syndrome Scale (PANSS) is the most widely used rating scale to assess psychotic symptoms in patients with schizophrenia and other primary psychoses. However, a definitive consensus regarding its dimensional structure remains elusive. The present work aims to determine the number of dimensions of the scale through a network analysis approach in a sample of individuals experiencing first-episode schizophrenia spectrum disorder (FE-SSD) with minimal or no prior exposure to antipsychotic treatment. Baseline data of 446 participants (age 25.96 ± 5.99 years, 70% males) enrolled in the OPTiMiSE trial were analysed. Exploratory Graph Analysis (EGA) was conducted to evaluate the dimensionality of the PANSS, and a bootstrap approach (bootEGA) was employed to assess model stability. The analysis was replicated, excluding unstable items with stability values below 0.75, until a stable model was achieved. The analysis of the 30 items of the PANSS revealed inadequate structural consistency, resulting in the exclusion of 9 unstable items. The final model comprised 21 symptoms distributed across four communities (Positive, Cognitive/Disorganised, Excited/Aggressive and Negative) but lacked a depressive domain. In conclusion, we propose a concise version of the PANSS, incorporating 21 items, to better assess the core symptoms of the first episode of SSD. This revised version provides clinicians with a robust psychometric tool with reduced administration time, but the complementary administration of a dedicated instrument for evaluating affective symptoms is advisable.

Interpretation of SNP combination effects on schizophrenia etiology based on stepwise deep learning with multi-precision data

Schizophrenia genome-wide association studies (GWAS) have reported many genomic risk loci, but it is unclear how they affect schizophrenia susceptibility through interactions of multiple SNPs. We propose a stepwise deep learning technique with multi-precision data (SLEM) to explore the SNP combination effects on schizophrenia through intermediate molecular and cellular functions. The SLEM technique utilizes two levels of precision data for learning. It constructs initial backbone networks with more precise but small amount of multilevel assay data. Then, it learns strengths of intermediate interactions with the less precise but massive amount of GWAS data. The learned networks facilitate identifying effective SNP interactions from the intractably large space of all possible SNP combinations. We have shown that the extracted SNP combinations show higher accuracy than any single SNPs and preserve the accuracy in an independent dataset. The learned networks also provide interpretations of molecular and cellular interactions of SNP combinations toward schizophrenia etiology.

DCC in the cerebral cortex is required for cognitive functions in mouse

Schizophrenia (SZ) is a highly heritable mental disorder, and genome-wide association studies have identified the association between deleted in colorectal cancer (DCC) and SZ. Previous study has shown a lowered expression of DCC in the cerebral cortex of SZ patient. In this study, we identified novel single nucleotide polymorphisms (SNPs) of DCC statistically correlated with SZ. Based on these, we generated DCC conditional knockout (CKO) mice and explored behavioral phenotypes in these mice. We observed that deletion of DCC in cortical layer VI but not layer V led to deficits in fear and spatial memory, as well as defective sensorimotor gating revealed by the prepulse inhibition test (PPI). Critically, the defective sensorimotor gating could be restored by olanzapine, an antipsychotic drug. Furthermore, we found that the levels of p-AKT and p-GSK3α/β were decreased, which was responsible for impaired PPI in the DCC-deficient mice. Finally, the DCC-deficient mice also displayed reduced spine density of pyramidal neurons and disturbed delta-oscillations. Our data, for the first time, identified and explored downstream substrates and signaling pathway of DCC which supports the hypothesis that DCC is a SZ-related risky gene and when defective, may promote SZ-like pathogenesis and behavioral phenotypes in mice.

Genetic Diversity in Schizophrenia: Developmental Implications of Ultra-Rare, Protein-Truncating Mutations

The genetic basis of schizophrenia (SZ) remains elusive despite its characterization as a highly heritable disorder. This incomplete understanding has led to stagnation in therapeutics and treatment, leaving many suffering with insufficient relief from symptoms. However, recent large-cohort genome- and exome-wide association studies have provided insights into the underlying genetic machinery. The scale of these studies allows for the identification of ultra-rare mutations that confer substantial disease risk, guiding clinicians and researchers toward general classes of genes that are central to SZ etiology. One such large-scale collaboration effort by the Schizophrenia Exome Sequencing Meta-Analysis consortium identified ten, high-risk, ultra-rare, protein-truncating variants, providing the clearest picture to date of the dysfunctional gene products that substantially increase risk for SZ. While genetic studies of SZ provide valuable information regarding "what" genes are linked with the disorder, it is an open question as to "when" during brain development these genetic mutations impose deleterious effects. To shed light on this unresolved aspect of SZ etiology, we queried the BrainSpan developmental mRNA expression database for these ten high-risk genes and discovered three general expression trajectories throughout pre- and postnatal brain development. The elusiveness of SZ etiology, we infer, is not only borne out of the genetic heterogeneity across clinical cases, but also in our incomplete understanding of how genetic mutations perturb neurodevelopment during multiple critical periods. We contextualize this notion within the National Institute of Mental Health's Research Domain Criteria framework and emphasize the utility of considering both genetic variables and developmental context in future studies.

Recognition of schizophrenia and quality of treatment during the COVID-19 pandemic: A Danish nationwide study

BACKGROUND

The COVID-19 pandemic may have exacerbated the state of ill-health among patients with schizophrenia. We examined the number of patients diagnosed with schizophrenia, the number of hospital admissions and outpatient contacts and the quality of treatment during the pandemic in comparison with the previous years.

METHODS

We identified patients ≥18 years old registered in the Danish Schizophrenia Registry from 2016 to 2022. Using a generalized linear model, we estimated prevalence ratios (PR) and 95 % confidence intervals (CI) for each variable of interest.

RESULTS

A minor reduction in the number of new cases, admissions and outpatient contacts was seen during the first lockdown; however, there was no overall change across the pandemic period compared with the pre-pandemic period. We found no change in the proportion of patients who were interviewed using a diagnostic tool (37.0 % during pandemic vs 37.9 % pre-pandemic; PR = 0.87; 95 % CI 0.68-1.12) or received family intervention (57.7 % vs 57.1 %; PR = 0.97; 95 % CI 0.81-1.15), and no decrease was observed in the proportion of patients assessed for social support. Furthermore, no change in the proportion of patients re-admitted within 30 days (35.9 % vs 35.0 %; PR = 0.96; 95 % CI 0.88-1.07) or screened for suicide risk in relation to discharge (55.2 % vs 56.8 %; PR = 0.96; 95 % CI 0.97-1.09) was observed.

CONCLUSIONS

Recognition and treatment of schizophrenia was minimally affected during the first lockdown, but across the pandemic period no overall change was observed. The quality of treatment of schizophrenia was unchanged.

Discovering functional interactions among schizophrenia-risk genes by combining behavioral genetics with cell biology

Despite much progress in identifying risk genes for polygenic brain disorders, their core pathogenic mechanisms remain poorly understood. In particular, functions of many proteins encoded by schizophrenia risk genes appear diverse and unrelated, complicating the efforts to establish the causal relationship between genes and behavior. Using various mouse lines, recent studies indicate that alterations of parvalbumin-positive (PV+) GABAergic interneurons can lead to schizophrenia-like behavior. PV+ interneurons display fast spiking and contribute to excitation-inhibition balance and network oscillations via feedback and feedforward inhibition. Here, we first summarize different lines of genetically modified mice that display motor, cognitive, emotional, and social impairments used to model schizophrenia and related mental disorders. We highlight ten genes, encoding either a nuclear, cytosolic, or membrane protein. Next, we discuss their functional relationship in regulating fast spiking and other aspects of PV+ interneurons and in the context of other domains of schizophrenia. Future investigations combining behavioral genetics and cell biology should elucidate functional relationships among risk genes to identify the core pathogenic mechanisms underlying polygenic brain disorders.

Individualized multi-modal MRI biomarkers predict 1-year clinical outcome in first-episode drug-naïve schizophrenia patients

Background

Antipsychotic medications offer limited long-term benefit to about 30% of patients with schizophrenia. We aimed to explore the individual-specific imaging markers to predict 1-year treatment response of schizophrenia.

Methods

Structural morphology and functional topological features related to treatment response were identified using an individualized parcellation analysis in conjunction with machine learning (ML). We performed dimensionality reductions using the Pearson correlation coefficient and three feature selection analyses and classifications using 10 ML classifiers. The results were assessed through a 5-fold cross-validation (training and validation cohorts, n = 51) and validated using the external test cohort (n = 17).

Results

ML algorithms based on individual-specific brain network proved more effective than those based on group-level brain network in predicting outcomes. The most predictive features based on individual-specific parcellation involved the GMV of the default network and the degree of the control, limbic, and default networks. The AUCs for the training, validation, and test cohorts were 0.947, 0.939, and 0.883, respectively. Additionally, the prediction performance of the models constructed by the different feature selection methods and classifiers showed no significant differences.

Conclusion

Our study highlighted the potential of individual-specific network parcellation in treatment resistant schizophrenia prediction and underscored the crucial role of feature attributes in predictive model accuracy.

Effects of acute and chronic ketamine administration on spontaneous and evoked brain activity

Schizophrenia is believed to be, at least in part, a dysfunction of the glutamatergic system. In line with anatomical evidence, suppressing N-methyl-D-aspartate (NMDA) neurotransmission leads to symptoms that are characteristic of schizophrenia. Rodent models of schizophrenia often involve the acute application of NMDA antagonists, which produce both behavioural and brain activity changes that closely resemble symptoms observed in schizophrenia. It is, however, important to note that the full spectrum of schizophrenia symptoms may not be manifested following the acute suppression of NMDA receptors. This has led to the proposal of a chronic model where NMDA receptors are suppressed for prolonged periods. Although the chronic model has shown promising results from a behavioural perspective and alterations in metabolic processes in the brain, its impact on brain oscillations remains largely unknown. The aim of this study is to examine the impact of acute and chronic NMDA neurotransmission suppression on brains' oscillatory activity. To achieve this, chronic brain activity recordings in mice of both sexes were used to assess both spontaneous and evoked brain oscillations. The study demonstrates that an acute suppression of NMDA receptors alters brain oscillations across a wide frequency spectrum and diminishes the oscillatory potency in evoked responses, paralleling changes observed in schizophrenia. However, the chronic suppression of NMDA receptors did not have the expected cumulative effect on brain activity. This research highlights the robust yet similar impacts of acute and chronic NMDA receptor suppression on brain activity, contributing to the nuanced understanding of rodent models of schizophrenia.

The neuromuscular basis of functional impairment in schizophrenia: A scoping review

Patients with schizophrenia exhibit functional impairments in their locomotory tasks, which decreases their quality of life. Due to the limited current research, the neuromuscular mechanisms behind the functional impairments in patients is not fully understood. Thus, this review aims to summarize the neuromuscular mechanisms that underlie these deficits in daily functioning. These deficits are speculated to stem from abnormalities at various levels from neurons through to the skeletal muscles. The neurological abnormalities are exhibited as lower motor neuron dysfunction whereas the skeletal muscle pathology is shown as increased muscle fibre (type 1 and type 2) atrophy, reduction in maximal force generation, and increased strength loss per decade. Although antipsychotics effectively reduce positive symptoms, functional impairments remain unresolved. Both endurance and resistance training have shown potential benefits in alleviating deficits in daily functioning by increasing muscular strength, increasing fat-free mass, and preserving neuromuscular properties from degradation. In summary, the review elucidates various possible mechanisms for the onset of functional impairment experienced by patients with schizophrenia and highlights the potential utility of endurance and resistance training to alleviate these deficits in daily functioning.

Peering into the mind: unraveling schizophrenia's secrets using models

Schizophrenia (SCZ) is a complex mental disorder characterized by a range of symptoms, including positive and negative symptoms, as well as cognitive impairments. Despite the extensive research, the underlying neurobiology of SCZ remain elusive. To overcome this challenge, the use of diverse laboratory modeling techniques, encompassing cellular and animal models, and innovative approaches like induced pluripotent stem cell (iPSC)-derived neuronal cultures or brain organoids and genetically engineered animal models, has been crucial. Immortalized cellular models provide controlled environments for investigating the molecular and neurochemical pathways involved in neuronal function, while iPSCs and brain organoids, derived from patient-specific sources, offer significant advantage in translational research by facilitating direct comparisons of cellular phenotypes between patient-derived neurons and healthy-control neurons. Animal models can recapitulate the different psychopathological aspects that should be modeled, offering valuable insights into the neurobiology of SCZ. In addition, invertebrates' models are genetically tractable and offer a powerful approach to dissect the core genetic underpinnings of SCZ, while vertebrate models, especially mammals, with their more complex nervous systems and behavioral repertoire, provide a closer approximation of the human condition to study SCZ-related traits. This narrative review provides a comprehensive overview of the diverse modeling approaches, critically evaluating their strengths and limitations. By synthesizing knowledge from these models, this review offers a valuable source for researchers, clinicians, and stakeholders alike. Integrating findings across these different models may allow us to build a more holistic picture of SCZ pathophysiology, facilitating the exploration of new research avenues and informed decision-making for interventions.

Efficacy and safety of a Chinese medicine formula Diankuang Mengxing Decoction combined with antipsychotics in the treatment of schizophrenia: A meta-analysis of randomized controlled trials

BACKGROUND

In patients with schizophrenia, Diankuang Mengxing Decoction with antipsychotics is one of the treatments for it. However, little information is available regarding the difference between the therapeutic effect of Diankuang Mengxing Decoction with antipsychotics and other treatments. Systematic evaluation is conducted to assess the efficacy and safety of Diankuang Mengxing Decoction and other antipsychotics, which are used to treat schizophrenia.

METHODS

We performed a systematic review (PROSPERO ID: CRD42023414603). This entailed a computerized search of several research databases from their respective dates of establishment until April 11, 2023, which collected clinical randomized controlled trials of Diankuang Mengxing Decoction combined with antipsychotics. The databases that contributed to this study were PubMed, Web of Science, Embase, EBSCOhost, Cochrane, Scopus, and Google Scholar. Each publication was screened according to defined inclusion and exclusion criteria, and appropriate literature was extracted and evaluated for quality, for which meta-analysis was performed using RevMan 5.4.

RESULTS

A literature review of 456 publications resulted in the inclusion of 18 randomized controlled trials with data collected from a total of 1636 patients. Meta-analytical results showed combination with risperidone, olanzapine, chlorpromazine, clozapine, ziprasidone, or aripiprazole increased the overall effectiveness of Diankuang Mengxing Decoction when treating schizophrenia (P < . 00001), among whom olanzapine demonstrated the greatest enhancement (Z = 3.65, odds ratio = 4.26, 95% CI: 1.96-9.28, P = .0003). The 4-week/30-day treatment (P = .0003) and a dosage of 400 mL/d of Diankuang Mengxing Decoction (P = .0004) were more effective. Also, there were widespread reductions to the Positive And Negative Syndrome Scale (PANSS) total scores, PANSS-positive symptom scores, PANSS-negative symptom scores, general psychopathology scores (P < .05 for all), as well as the incidence of adverse effects (Z = 2.79, odds ratio = 0.34, 95% CI: 0.16-0.73, P = .005) in patients with schizophrenia.

CONCLUSION

The combination of Diankuang Mengxing Decoction with different antipsychotics can improve the overall prognosis of patients with schizophrenia; Diankuang Mengxing Decoction combined olanzapine, a dosage of 400 mL/d and a duration of 4 weeks/30 days being the best in this regard, by alleviating the symptoms and diminishing the disorder's adverse effects. To build on this work, more large-sample, multi-center, and high-quality clinical studies in the future would help to further validate our findings.

Uncovering convergence and divergence between autism and schizophrenia using genomic tools and patients' neurons

Autism spectrum disorders (ASDs) are highly heritable and result in abnormal repetitive behaviors and impairment in communication and cognitive skills. Previous studies have focused on the genetic correlation between ASDs and other neuropsychiatric disorders, but an in-depth understanding of the correlation to other disorders is required. We conducted an extensive meta-analysis of common variants identified in ASDs by genome-wide association studies (GWAS) and compared it to the consensus genes and single nucleotide polymorphisms (SNPs) of Schizophrenia (SCZ). We found approximately 75% of the GWAS genes that are associated with ASD are also associated with SCZ. We further investigated the cellular phenotypes of neurons derived from induced pluripotent stem cell (iPSC) models in ASD and SCZ. Our findings revealed that ASD and SCZ neurons initially follow divergent developmental trajectories compared to control neurons. However, despite these early diametrical differences, both ASD and SCZ neurons ultimately display similar deficits in synaptic activity as they mature. This significant genetic overlap between ASD and SCZ, coupled with the convergence towards similar synaptic deficits, highlights the intricate interplay of genetic and developmental factors in shaping the shared underlying mechanisms of these complex neurodevelopmental and neuropsychiatric disorders.

Healthcare utilization and economics evaluation of paliperidone palmitate once-monthly in schizophrenia: a one-year, real-world, and retrospective mirror image study in China

Background

Investigation and analysis of the changes in healthcare resources and burden of schizophrenia in the real world before and after switching from oral antipsychotics (OAPs) to paliperidone palmitate once-monthly (PP1M) could provide evidence to clinicians and patients for choosing treatment modality and data support for health policy optimization.

Methods

The first dosage of PP1M was set as mirror point, and patients with mirror point between January 2020 and June 2022 were recruited in the study. The differences in treatment patterns, healthcare resource utilization, and costs within one year before and after the mirror point were compared.

Results

A total of 72 patients transitioning from OAPs to PP1M (mean age, 35.33 years; 43.06% female) were included in the study. Of the 72 patients, the application of PP1M resulted in a significant reduction in the hospitalization times, emergency room visits, and direct medical costs (P < 0.001), while the pharmacy cost and total cost increased by 222.57% (P < 0.001) and 16.35% (P < 0.001), respectively; PP1M accounted for 88.48% of the pharmacy cost. For patients with ≥1 hospitalization during the OAPs phase (n = 25), the number of hospitalizations, hospitalization days and hospitalization expenses decreased by more than 90% (P < 0.001). Total one-year expenses decreased by 37.67% (P < 0.001), and pharmacy expenses increased by 185.21% (P < 0.001). For patients with no hospitalizations during the OAPs phase (n = 47), emergency and outpatient visits decreased by 70% (P < 0.001) and 30.27% (P < 0.05), respectively, while the total cost increased by 117.56% (P < 0.001), and the pharmacy cost increased by 260.15% (P < 0.001) after initiation of PP1M treatment.

Conclusion

After the transition to PP1M, the number of hospitalizations and outpatient and emergency department visits reduced, and healthcare resources were conserved. Switching to PP1M may be more economically beneficial for patients with prior hospitalizations while on OAP regimens. The high price of PP1M might be an obstacle to its widespread use.

Aberrant brain functional connectivity mediates the effects of negative symptoms on cognitive function in schizophrenia: A structural equation model

BACKGROUND

Schizophrenia is a severe psychiatric disorder, characterized by positive symptoms, negative symptoms, and cognitive deficits. Elucidating the mechanism of negative symptom and cognitive deficits could contribute to the treatment and prognosis of schizophrenia. We hypothesized that abnormal functional connectivity would be involved in the indirect effects of negative symptoms on cognitive function.

METHODS

A total of 150 schizophrenia male patients and 108 healthy controls matched for age, education and gender were enrolled in the study. The scores of Brief Negative Symptom Scale were divided into two factors: motivation and pleasure deficits (MAP) and diminished expression (EXP). Subsequently, a series of classic neurocognitive tests were used to evaluate cognitive functions. Resting-state fMRI data was collected from all participants. The Anatomical Automatic Labeling template was employed to establish regions of interest, thereby constructing the functional connectivity network across the entire brain. Eventually, scores of patients' negative symptoms scale, cognitive function, and strengths of abnormal functional connectivity were incorporated into a structural equation model to explore the interactions among variables.

RESULTS

MAP exhibited a distinctly and significantly negative impact on cognitive function. The functional connectivity between the left insula and left precuneus, along with that between the left precuneus and right angular gyrus, collectively served as intermediaries, contributing to the indirect effects of MAP and EXP on cognitive function.

CONCLUSIONS

Our findings demonstrated the moderating role of aberrant brain functional connectivity between negative symptoms and cognitive function, providing clues about the neural correlates of negative symptoms and cognitive deficits in schizophrenia.

Longitudinal course of core cognitive domains in first-episode acute and transient psychotic disorders compared with schizophrenia

Acute and transient psychotic disorder (ATPD) is characterized by acute onset of psychotic symptoms and early recovery. Contrastingly, schizophrenia (SZ) is a chronic mental disorder characterized by impaired functioning including a deficit in cognition. In SZ, the cognitive deficit is among the core symptoms, but in ATPDs, the existing evidence brings mixed results. Our primary aim was to compare three core cognitive domains (executive functioning/abstraction, speed of processing and working memory) of patients diagnosed with ATPD and SZ over a 12-month period. Moreover, we explored how these diagnostic subgroups differed in their clinical characteristics. We recruited 39 patients with a diagnosis of SZ and 31 with ATPD with schizophrenic symptoms. All patients completed clinical and neuropsychological assessments. At baseline, we used a one-way ANCOVA model with a group as the between-subjects factor. Mixed-model repeated-measures ANOVAs with time as the within-subjects factor and group as the between-subjects factor were run to test the overtime differences. At baseline, we did not find any differences in cognition - with sex, education and age as covariates - between ATPDs and SZ. After one year, all patients showed an improvement in all three domains, however, there were no significant overtime changes between ATPDs and SZ. Regarding clinical profiles, ATPDs demonstrated less severe psychopathology and better functioning compared to SZ both at baseline and after 12 months. The medication dosage differed at retest, but not at baseline between the groups. Our findings suggest clinical differences and a similar trajectory of cognitive performance between these diagnostic subgroups.

Unveiling Promising Neuroimaging Biomarkers for Schizophrenia Through Clinical and Genetic Perspectives

Schizophrenia is a complex and serious brain disorder. Neuroscientists have become increasingly interested in using magnetic resonance-based brain imaging-derived phenotypes (IDPs) to investigate the etiology of psychiatric disorders. IDPs capture valuable clinical advantages and hold biological significance in identifying brain abnormalities. In this review, we aim to discuss current and prospective approaches to identify potential biomarkers for schizophrenia using clinical multimodal neuroimaging and imaging genetics. We first described IDPs through their phenotypic classification and neuroimaging genomics. Secondly, we discussed the applications of multimodal neuroimaging by clinical evidence in observational studies and randomized controlled trials. Thirdly, considering the genetic evidence of IDPs, we discussed how can utilize neuroimaging data as an intermediate phenotype to make association inferences by polygenic risk scores and Mendelian randomization. Finally, we discussed machine learning as an optimum approach for validating biomarkers. Together, future research efforts focused on neuroimaging biomarkers aim to enhance our understanding of schizophrenia.

Abnormal Global Cortical Responses in Drug-Naïve Patients With Schizophrenia Following Orbitofrontal Cortex Stimulation: A Concurrent Transcranial Magnetic Stimulation-Electroencephalography Study

BACKGROUND

Abnormalities in cortical excitability and plasticity have been considered to underlie the pathophysiology of schizophrenia. Transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) can provide a direct evaluation of cortical responses to TMS. Here, we employed TMS-EEG to investigate cortical responses to orbitofrontal cortex (OFC) stimulation in schizophrenia.

METHODS

In total, we recruited 92 drug-naïve patients with first-episode schizophrenia and 51 age- and sex-matched healthy individuals. For each participant, one session of 1-Hz repetitive TMS (rTMS) was delivered to the right OFC, and TMS-EEG data were obtained to explore the change in cortical-evoked activities before and immediately after rTMS during the eyes-closed state. The MATRICS Consensus Cognitive Battery was used to assess neurocognitive performance.

RESULTS

The cortical responses indexed by global mean field amplitudes (i.e., P30, N45, and P60) were larger in patients with schizophrenia than in healthy control participants at baseline. Furthermore, after one session of 1-Hz rTMS over the right OFC, the N100 amplitude was significantly reduced in the healthy control group but not in the schizophrenia group. In the healthy control participants, there was a significant correlation between modulation of P60 amplitude by rTMS and working memory; however, this correlation was absent in patients with schizophrenia.

CONCLUSIONS

Aberrant global cortical responses following right OFC stimulation were found in patients with drug-naïve first-episode schizophrenia, supporting its significance in the primary pathophysiology of schizophrenia.

Effect of personality traits, psychological resilience and life adversities on lifetime violence trajectories: A novel classification model in schizophrenia

The risk of violence is higher in schizophrenia spectrum disorders (SSD) compared to the general population and it is a pressing and understudied issue. Several dispositional and environmental factors have been previously correlated with violence, however, there has been little success in assessing their ability to predict violence patterns across the life span. This study aims to assess violence prediction based on personality traits, psychological resilience, and life-course adversities in a non-forensic population of SSD patients. In a sample of 231 patients with SSD, we assessed violence using the Brown-Goodwin History of Lifetime Aggression Scale and conducted cross-sectional assessments of possible predictors such as childhood trauma, personality traits and resilience scores. We then utilized a logistic regression classification algorithm to predict different violence trajectories based on the proposed risk factors. Our model significantly predicted individuals with violence in both childhood and adulthood, as well as childhood-only violence (p < 0.001). However, the model did not show significance for adult-only violence (p = 0.604). In all given trajectories, female sex appeared to be protective against violence, while stressful life events appeared to contribute to it. These results suggest that distinct factors can better inform risk assessment of lifespan violence patterns for personalized interventions in SSD.

Safety, tolerability and pharmacokinetics of the phosphodiesterase 2 inhibitor BI 474121: An overview of phase I randomized trials in healthy volunteers

BACKGROUND

Cognitive impairment associated with schizophrenia predicts poor functional outcomes, but currently no efficacious pharmacotherapies are available.

AIMS

Four phase I trials examined the safety, tolerability and pharmacokinetics of the phosphodiesterase 2 inhibitor BI 474121, along with potential drug-drug interactions.

METHODS

Trial 1 evaluated single rising doses (SRDs) of BI 474121 versus placebo in healthy males. The influence of drug formulation and food on drug bioavailability was also examined. Trial 2 evaluated SRD of BI 474121 versus placebo in healthy Japanese males. Trial 3 evaluated multiple rising doses of BI 474121 in healthy young (with/without midazolam) and elderly (without midazolam) participants versus placebo. Trial 4 investigated interactions between itraconazole and single-dose BI 474121 in healthy males.

RESULTS/OUTCOMES

No deaths, serious adverse events (AEs), severe AEs or protocol-specified AEs of special interest were observed. BI 474121 absorbed rapidly during fasting, achieved maximum concentration of analyte in plasma and dose proportionality via tablet formulation, and decreased in a multiphasic manner. BI 474121 steady state occurred within 11 days of multiple oral administration. Multiple doses increased BI 474121 plasma concentrations, but did not alter the time course of plasma concentrations. Urinary excretion of unchanged BI 474121 was negligible. No clinically relevant inhibition or induction of CYP3A4 by BI 474121 was observed. Itraconazole co-administration produced higher exposures of BI 474121 versus BI 474121 alone.

CONCLUSIONS/INTERPRETATION

BI 474121 demonstrated favourable safety and pharmacokinetic profiles in healthy Caucasian and Japanese individuals, supporting further clinical development.

Impact of HCV cure on subsequent hospitalizations in people with mental disorders: Results from the French claims database

BACKGROUND AND AIMS

Although HCV cure after direct-acting antiviral (DAA) treatment is associated with hepatic and extrahepatic benefits, few studies have assessed the impact of HCV treatment in people with mental disorders (PWMDs). Using quasi-exhaustive national data from the French administrative health care databases (SNDS), we explored whether DAA treatment in PWMDs affected hospitalizations in both psychiatric and non-psychiatric settings.

METHODS

All adult PWMDs identified in the SNDS with DAA treatment initiation between 2015 and 2018 and 12 months of data pre- and post-treatment were included. Individuals were algorithmically classified into one or several subgroups: "addictive disorders", "neurotic and mood disorders", "psychotic disorders" and "other psychiatric disorders". A longitudinal approach was used to compare the frequency and duration of hospitalizations one year before and one year after DAA treatment.

RESULTS

In total, 17,203 individuals met the inclusion criteria. The number of patients with at least one hospitalization (any type) decreased by 28% after HCV cure. The mean numbers of hospitalizations in non-psychiatric units per patient per year were 1·2 during the pre-DAA period and 0·8 during the post-DAA period (p < 0·0001). Similarly, the number of hospitalizations in psychiatric wards decreased from 1·4 to 1·2 (p = 0.006). The duration of hospital stays decreased from 20·2 days to 16·7 days in non-psychiatric settings (p < 0·0001). These results were also homogeneous and significant across all subgroups.

CONCLUSIONS

HCV cure significantly lowered the frequency and duration of hospitalizations during the year following treatment in all PWMDs subgroups, including the psychotic disorders subgroup.

FUNDING

This study was funded by Gilead Sciences.

Analysis of single-cell transcriptome data from a mouse model implicates protein synthesis dysfunction in schizophrenia

BACKGROUND

Schizophrenia is a mental disorder that causes considerable morbidity, whose risk largely results from genetic factors. Setd1a is a gene implicated in schizophrenia.

OBJECTIVE

To study the gene expression changes found in heterozygous Setd1a± knockout mice in order to gain useful insight into schizophrenia pathogenesis.

METHODS

We mined a single-cell RNA sequencing (scRNAseq) dataset from the prefrontal cortex (PFC) and striatum of Setd1a± mice and identified cell type-specific differentially expressed genes (DEGs) and differential transcript usage (DTU). DEGs and genes containing DTU found in each cell type were used to identify affected biological pathways using Ingenuity Pathway Analysis (IPA).

RESULTS

We identified 273 unique DEGs across all cell types in PFC and 675 unique gene peaks containing DTU. In striatum, we identified 327 unique DEGs across all cell types and 8 unique gene peaks containing DTU. Key IPA findings from the analysis of DEGs found in PFC and striatum implicate processes involved in protein synthesis, mitochondrial function, cell metabolism, and inflammation. IPA analysis of genes containing DTU in PFC points to protein synthesis, as well as cellular activities involving intracellular signaling and neurotransmission. One canonical pathway, 'EIF2 Signaling', which is involved in the regulation of protein synthesis, was detected in PFC DEGs, striatum DEGs, and PFC genes containing DTU, drawing attention to its importance in schizophrenia pathophysiology.

CONCLUSION

Processes involving protein synthesis in general and the 'EIF2 Signaling' pathway in particular could be targets for the development of new research strategies and biomarkers in schizophrenia.

Daidzin enhances memory and the antischizophrenia drug olanzapine's effects, possibly through the 5-HT2A and D2 receptor interaction pathways

Schizophrenia affects identification and disturbs our thinking and motivational capacity. Long-term use of daidzin (DZN) is evident to enhance attention and memory in experimental animals. This study aimed to investigate the effect of DZN on Swiss mice. To check animals' attention, identification, thinking, and motivational ability, we performed behavioral studies using marble burying, dust removal, and trained swimming protocols. For this, a total of 36 male Swiss albino mice were randomly divided into six groups, consisting of 6 animals in each group, as follows: control (vehicle), DZN-1.25, DZN-2.5, DZN-5 mg/kg, olanzapine (OLN)-2, and a combination of DZN-1.25 with OLN-2. Additionally, in silico studies are also performed to understand the possible molecular mechanisms behind this neurological effect. Findings suggest that DZN dose-dependently and significantly (p < .05) increased marble burying and removed dust while reducing the time to reach the target point. DZN-1.25 was found to enhance OLN's effect significantly (p < .05), possibly via agonizing its activity in animals. In silico findings suggest that DZN has strong binding affinities of -10.1 and -10.4 kcal/mol against human serotonin 2 A (5-HT2A) and dopamine 2 (D2) receptors, respectively. Additionally, DZN exhibits favorable pharmacokinetic and toxicity properties. We suppose that DZN may exert its attention- and memory-enhancing abilities by interacting with 5-HT2A and D2 receptors. It may exert a synergistic antischizophrenia-like effect with the standard drug, OLN. Further studies are required to discover the exact molecular mechanism for this neurological function in animals.

Exploring the gut-brain Axis: Potential therapeutic impact of Psychobiotics on mental health

One of the most challenging and controversial issues in microbiome research is related to gut microbial metabolism and neuropsychological disorders. Psychobiotics affect human behavior and central nervous system processes via the gut-brain axis, involving neuronal, immune, and metabolic pathways. They have therapeutic potential in the treatment of several neurodegenerative and neurodevelopmental disorders such as depression, anxiety, autism, attention deficit hyperactivity disorder, Alzheimer's disease, Parkinson's disease, schizophrenia, Huntington's disease, anorexia nervosa, and multiple sclerosis. However, the mechanisms underlying the interaction between psychobiotics and the abovementioned diseases need further exploration. This review focuses on the relationship between gut microbiota and its impact on neurological and neurodegenerative disorders, examining the potential of psychobiotics as a preventive and therapeutic approach, summarising recent research on the gut-brain axis and the potential beneficial effects of psychobiotics, highlighting the need for further research and investigation in this area.

Schizophrenia and Neurodevelopment: Insights From Connectome Perspective

BACKGROUND

Schizophrenia is conceptualized as a brain connectome disorder that can emerge as early as late childhood and adolescence. However, the underlying neurodevelopmental basis remains unclear. Recent interest has grown in children and adolescent patients who experience symptom onset during critical brain development periods. Inspired by advanced methodological theories and large patient cohorts, Chinese researchers have made significant original contributions to understanding altered brain connectome development in early-onset schizophrenia (EOS).

STUDY DESIGN

We conducted a search of PubMed and Web of Science for studies on brain connectomes in schizophrenia and neurodevelopment. In this selective review, we first address the latest theories of brain structural and functional development. Subsequently, we synthesize Chinese findings regarding mechanisms of brain structural and functional abnormalities in EOS. Finally, we highlight several pivotal challenges and issues in this field.

STUDY RESULTS

Typical neurodevelopment follows a trajectory characterized by gray matter volume pruning, enhanced structural and functional connectivity, improved structural connectome efficiency, and differentiated modules in the functional connectome during late childhood and adolescence. Conversely, EOS deviates with excessive gray matter volume decline, cortical thinning, reduced information processing efficiency in the structural brain network, and dysregulated maturation of the functional brain network. Additionally, common functional connectome disruptions of default mode regions were found in early- and adult-onset patients.

CONCLUSIONS

Chinese research on brain connectomes of EOS provides crucial evidence for understanding pathological mechanisms. Further studies, utilizing standardized analyses based on large-sample multicenter datasets, have the potential to offer objective markers for early intervention and disease treatment.

Analysis of lumateperone data for patients with schizophrenia using related adverse events from the FDA adverse reporting system

BACKGROUND

Our study utilized the U.S. Food and Drug Administration's Adverse Event Reporting System (FAERS) to analyze and study the adverse event (AEs) signals of second-generation antipsychotic drug lumateperone, providing a reference for clinical safety monitoring in the treatment of schizophrenia.

METHODS

The International Dictionary of Medical Terminology (version 26.0) was used to standardize the preferred system organ category (SOC) and preferred terminology (PT) for adverse drug events (ADE) data related to lumateperone. ADE signals were classified and described using four algorithms: reporting odds ratios (ROR), proportional reporting ratios (PRR), Bayesian confidence-propagation neural network (BCPNN) and Multinomial gamma-poisson shrinkage (MGPS).

RESULT

Among the 2542 case reports collected from the FAERS database, 1762 reports with lumateperone as a 'principal suspect(PS)' AEs were identified. Lumateperone-induced AEs occurred in 26 system organ categories (SOC). A total of 118 significant disproportionate preferred terms (PTs) meeting the requirements of 4 algorithms were retained, and unexpected major events, such as burning sensation, tremor, migraine etc. may also occur. The median time to onset of lumateperone-related adverse events was 9 days (interquartile range [IQR] 2-31.25 days), and most AEs occurred within the first 10 days and 1 month after initiation of lumateperone therapy.

CONCLUSION

Our research may provide a better understanding of the potential adverse events that may be caused by lumateperone and those not recorded in the drug instructions, providing valuable signals for clinical use.

Multitrait Genetic Analysis Identifies Novel Pleiotropic Loci for Depression and Schizophrenia in East Asians

BACKGROUND AND HYPOTHESIS

While genetic correlations, pleiotropic loci, and shared genetic mechanisms of psychiatric disorders have been extensively studied in European populations, the investigation of these factors in East Asian populations has been relatively limited.

STUDY DESIGN

To identify novel pleiotropic risk loci for depression and schizophrenia (SCZ) in East Asians. We utilized the most comprehensive dataset available for East Asians and quantified the genetic overlap between depression, SCZ, and their related traits via a multitrait genome-wide association study. Global and local genetic correlations were estimated by LDSC and ρ-HESS. Pleiotropic loci were identified by the multitrait analysis of GWAS (MTAG).

STUDY RESULTS

Besides the significant correlation between depression and SCZ, our analysis revealed genetic correlations between depression and obesity-related traits, such as weight, BMI, T2D, and HDL. In SCZ, significant correlations were detected with HDL, heart diseases and use of various medications. Conventional meta-analysis of depression and SCZ identified a novel locus at 1q25.2 in East Asians. Further multitrait analysis of depression, SCZ and related traits identified ten novel pleiotropic loci for depression, and four for SCZ.

CONCLUSIONS

Our findings demonstrate shared genetic underpinnings between depression and SCZ in East Asians, as well as their associated traits, providing novel candidate genes for the identification and prioritization of therapeutic targets specific to this population.

Shared Genetic Architecture Among Gastrointestinal Diseases, Schizophrenia, and Brain Subcortical Volumes

BACKGROUND AND HYPOTHESIS

The gut-brain axis plays important roles in both gastrointestinal diseases (GI diseases) and schizophrenia (SCZ). Moreover, both GI diseases and SCZ exhibit notable abnormalities in brain subcortical volumes. However, the genetic mechanisms underlying the comorbidity of these diseases and the shared alterations in brain subcortical volumes remain unclear.

STUDY DESIGN

Using the genome-wide association studies data of SCZ, 14 brain subcortical volumes, and 8 GI diseases, the global polygenic overlap and local genetic correlations were identified, as well as the shared genetic variants among those phenotypes. Furthermore, we conducted multi-trait colocalization analyses to bolster our findings. Functional annotations, cell-type enrichment, and protein-protein interaction (PPI) analyses were carried out to reveal the critical etiology and pathology mechanisms.

STUDY RESULTS

The global polygenic overlap and local genetic correlations informed the close relationships between SCZ and both GI diseases and brain subcortical volumes. Moreover, 84 unique lead-shared variants were identified. The associated genes were linked to vital biological processes within the immune system. Additionally, significant correlations were observed with key immune cells and the PPI analysis identified several histone-associated hub genes. These findings highlighted the pivotal roles played by the immune system for both SCZ and GI diseases, along with the shared alterations in brain subcortical volumes.

CONCLUSIONS

These findings revealed the shared genetic architecture contributing to SCZ and GI diseases, as well as their shared alterations in brain subcortical volumes. These insights have substantial implications for the concurrent development of intervention and therapy targets for these diseases.

Shared Genetic Architecture Between Schizophrenia and Anorexia Nervosa: A Cross-trait Genome-Wide Analysis

BACKGROUND AND HYPOTHESIS

Schizophrenia (SCZ) and anorexia nervosa (AN) are 2 severe and highly heterogeneous disorders showing substantial familial co-aggregation. Genetic factors play a significant role in both disorders, but the shared genetic etiology between them is yet to be investigated.

STUDY DESIGN

Using summary statistics from recent large genome-wide association studies on SCZ (Ncases = 53 386) and AN (Ncases = 16 992), a 2-sample Mendelian randomization analysis was conducted to explore the causal relationship between SCZ and AN. MiXeR was employed to quantify their polygenic overlap. A conditional/conjunctional false discovery rate (condFDR/conjFDR) framework was adopted to identify loci jointly associated with both disorders. Functional annotation and enrichment analyses were performed on the shared loci.

STUDY RESULTS

We observed a cross-trait genetic enrichment, a suggestive bidirectional causal relationship, and a considerable polygenic overlap (Dice coefficient = 62.2%) between SCZ and AN. The proportion of variants with concordant effect directions among all shared variants was 69.9%. Leveraging overlapping genetic associations, we identified 6 novel loci for AN and 33 novel loci for SCZ at condFDR <0.01. At conjFDR <0.05, we identified 10 loci jointly associated with both disorders, implicating multiple genes highly expressed in the cerebellum and pituitary and involved in synapse organization. Particularly, high expression of the shared genes was observed in the hippocampus in adolescence and orbitofrontal cortex during infancy.

CONCLUSIONS

This study provides novel insights into the relationship between SCZ and AN by revealing a shared genetic component and offers a window into their complex etiology.

A Global, Regional, and National Burden and Quality of Care Index for Schizophrenia: Global Burden of Disease Systematic Analysis 1990-2019

BACKGROUND AND HYPOTHESIS

Schizophrenia is a mental disorder usually presented in adulthood that affects roughly 0.3 percent of the population. The disease contributes to more than 13 million years lived with disability the global burden of disease. The current study aimed to provide new insights into the quality of care in Schizophrenia via the implementation of the newly introduced quality of care index (QCI) into the existing data.

STUDY DESIGN

The data from the global burden of disease database was used for schizophrenia. Two secondary indices were calculated from the available indices and used in a principal component analysis to develop a proxy of QCI for each country. The QCI was then compared between different sociodemographic index (SDI) and ages. To assess the disparity in QCI between the sexes, the gender disparity ratio (GDR) was also calculated and analyzed in different ages and SDIs.

STUDY RESULTS

The global QCI proxy score has improved between 1990 and 2019 by roughly 13.5%. Concerning the gender disparity, along with a rise in overall GDR the number of countries having a GDR score of around one has decreased which indicates an increase in gender disparity regarding quality of care of schizophrenia. Bhutan and Singapore had 2 of the highest QCIs in 2019 while also showing GDR scores close to one.

CONCLUSIONS

While the overall conditions in the quality of care have improved, significant disparities and differences still exist between different countries, genders, and ages in the quality of care regarding schizophrenia.

Effects of Antipsychotics on the Hypothalamus-Pituitary-Adrenal Axis in a Phencyclidine Animal Model of Schizophrenia

Schizophrenia (SCH) is a mental disorder that requires long-term antipsychotic treatment. SCH patients are thought to have an increased sensitivity to stress. The dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, observed in SCH, could include altered levels of glucocorticoids, glucocorticoid receptors (GRs), and associated proteins. The perinatal administration of phencyclidine (PCP) to rodents represents an animal model of SCH. This study investigated the effects of perinatal PCP exposure and subsequent haloperidol/clozapine treatment on corticosterone levels measured by ELISA and the expression of GR-related proteins (GR, pGR, HSP70, HSP90, FKBP51, and 11β-Hydroxysteroid dehydrogenase-11β-HSD) determined by Western blot, in different brain regions of adult rats. Six groups of male rats were treated on the 2nd, 6th, 9th, and 12th postnatal days (PN), with either PCP or saline. Subsequently, one saline and one PCP group received haloperidol/clozapine from PN day 35 to PN day 100. The results showed altered GR sensitivity in the rat brain after PCP exposure, which decreased after haloperidol/clozapine treatment. These findings highlight disturbances in the HPA axis in a PCP-induced model of SCH and the potential protective effects of antipsychotics. To the best of our knowledge, this is the first study to investigate the effects of antipsychotic drugs on the HPA axis in a PCP animal model of SCH.

All-cause mortality risk in long-acting injectable versus oral antipsychotics in schizophrenia: a systematic review and meta-analysis

Patients with schizophrenia receiving antipsychotic treatment present lower mortality rates than those who do not. However, the non-adherence rate is high, which can be partially addressed using long-acting injectable (LAI) antipsychotics. The impact of LAI treatments on all-cause mortality compared to oral antipsychotics remains unclear. To fill that gap, a random effects meta-analysis was conducted to analyze the odds ratio (OR) of all-cause, suicidal, and non-suicidal mortality among patients taking LAI antipsychotics compared to oral antipsychotics (PROSPERO:CRD42023391352). Individual and pooled LAI antipsychotics were analyzed against pooled oral antipsychotics. Sensitivity analyses were performed for study design, setting, and industry sponsorship. Meta-regressions were conducted for gender, age, antipsychotic dose, and race. Seventeen articles, total sample 12,042 patients (N = 5795 oral, N = 6247 LAI) were included. Lower risk of all-cause mortality for patients receiving LAI antipsychotics vs receiving oral antipsychotics was found (OR = 0.79; 95%CI = 0.66-0.95). Statistical significance was maintained when only studies comparing the same LAI and oral antipsychotic were included (OR = 0.79; 95%CI = 0.66-0.95; p = <0.01), as well as for non-suicidal mortality (OR = 0.77: 95%CI = 0.63-0.94; p = 0.01), but not for suicidal mortality (OR = 0.86; 95%CI = 0.59-1.26; p = 0.44). Mortality reduction was more pronounced for LAI antipsychotics in first-episode psychosis (FEP) (OR = 0.79; 95%CI = 0.66-0.96) compared to chronic psychosis. No individual LAI reported statistically significant differences against all pooled oral antipsychotics. LAI antipsychotics are associated with a lower risk of all-cause and non-suicidal mortality in individuals with schizophrenia compared to oral antipsychotics. Better adherence to the medication and health services may explain this difference. Whenever possible, the use of LAIs should be considered from the FEP.

Air pollutants, genetic susceptibility and the risk of schizophrenia: large prospective study

BACKGROUND

Evidence linking air pollutants and the risk of schizophrenia remains limited and inconsistent, and no studies have investigated the joint effect of air pollutant exposure and genetic factors on schizophrenia risk.

AIMS

To investigate how exposure to air pollution affects schizophrenia risk and the potential effect modification of genetic susceptibility.

METHOD

Our study was conducted using data on 485 288 participants from the UK Biobank. Cox proportional hazards models were used to estimate the schizophrenia risk as a function of long-term air pollution exposure presented as a time-varying variable. We also derived the schizophrenia polygenic risk score (PRS) utilising data provided by the UK Biobank, and investigated the modification effect of genetic susceptibility.

RESULTS

During a median follow-up period of 11.9 years, 417 individuals developed schizophrenia (mean age 55.57 years, s.d. = 8.68; 45.6% female). Significant correlations were observed between long-term exposure to four air pollutants (PM2.5; PM10; nitrogen oxides, NOx; nitrogen dioxide, NO2) and the schizophrenia risk in each genetic risk group. Interactions between genetic factors and the pollutants NO2 and NOx had an effect on schizophrenia events. Compared with those with low PRS and low air pollution, participants with high PRS and high air pollution had the highest risk of incident schizophrenia (PM2.5: hazard ratio = 6.25 (95% CI 5.03-7.76); PM10: hazard ratio = 7.38 (95% CI 5.86-9.29); NO2: hazard ratio = 6.31 (95% CI 5.02-7.93); NOx: hazard ratio = 6.62 (95% CI 5.24-8.37)).

CONCLUSIONS

Long-term exposure to air pollutants was positively related to the schizophrenia risk. Furthermore, high genetic susceptibility could increase the effect of NO2 and NOx on schizophrenia risk.

Bayesian Rare Variant Analysis Identifies Novel Schizophrenia Putative Risk Genes

The genetics of schizophrenia is so complex that it involves both common variants and rare variants. Rare variant association studies of schizophrenia are challenging because statistical methods for rare variant analysis are under-powered due to the rarity of rare variants. The recent Schizophrenia Exome meta-analysis (SCHEMA) consortium, the largest consortium in this field to date, has successfully identified 10 schizophrenia risk genes from ultra-rare variants by burden test, while more risk genes remain to be discovered by more powerful rare variant association test methods. In this study, we use a recently developed Bayesian rare variant association method that is powerful for detecting sparse rare risk variants that implicates 88 new candidate risk genes associated with schizophrenia from the SCHEMA case-control sample. These newly identified genes are significantly enriched in autism risk genes and GO enrichment analysis indicates that new candidate risk genes are involved in mechanosensory behavior, regulation of cell size, neuron projection morphogenesis, and plasma-membrane-bounded cell projection morphogenesis, that may provide new insights on the etiology of schizophrenia.

Role of Semaphorin 3A in common psychiatric illnesses such as schizophrenia, depression, and anxiety

With societal development and an ageing population, psychiatric disorders have become a common cause of severe and long-term disability and socioeconomic burdens worldwide. Semaphorin 3A (Sema-3A) is a secreted glycoprotein belonging to the semaphorin family. Sema-3A is well known as an axon guidance factor in the neuronal system and a potent immunoregulator at all stages of the immune response. It is reported to have various biological functions and is involved in many human diseases, including autoimmune diseases, angiocardiopathy, osteoporosis, and tumorigenesis. The signals of sema-3A involved in the pathogenesis of these conditions, are transduced through its cognate receptors and diverse downstream signalling pathways. An increasing number of studies show that sema-3A plays important roles in synaptic and dendritic development, which are closely associated with the pathophysiological mechanisms of psychiatric disorders, including schizophrenia, depression, and autism, suggesting the involvement of sema-3A in the pathogenesis of mental diseases. This indicates that mutations in sema-3A and alterations in its receptors and signalling may compromise neurodevelopment and predispose patients to these disorders. However, the role of sema-3A in psychiatric disorders, particularly in regulating neurodevelopment, remains elusive. In this review, we summarise the recent progress in understanding sema-3A in the pathogenesis of mental diseases and highlight sema-3A as a potential target for the prevention and treatment of these diseases.