Definition and description of schizophrenia in the DSM-5

The effects of selected phytochemicals on schizophrenia symptoms: A review

There are suggested treatment options for schizophrenia (SZ), including antipsychotic medications. Unfortunately, these drugs mostly ameliorate only the positive symptoms of SZ, and patients have less tendency for compliance due to the drug's side effects. Hence, there is a need for additional or adjunct therapeutic options. This review considers selected phytochemicals with anti-schizophrenic activity as an alternative therapy. We searched the scientific literature and reviewed the evidence from pre-clinical (animal) and clinical studies using some phytochemicals in SZ. The reviewed phytochemicals provided varying potential beneficial effects on SZ. Of particular interest, berberine may provide additional ameliorative advantages against the disorder. Although still nascent in scientific research, these studies suggest a potential adjunct therapeutic option against the pathophysiological pathways implicated in SZ. We recommend robust, carefully performed randomized controlled trials evaluating the role of these phytochemicals in SZ.

A cross-sectional study on the association between executive functions and social disabilities in people with a psychotic disorder

Background

Social recovery (SR) in people with psychotic disorders involves taking on social roles and completing daily tasks. Functional recovery (FR), particularly executive functions, is critical for these roles. Psychotic disorder patients often experience severe cognitive impairments, especially in executive functions. This study investigates the relationship between functional and social recovery in individuals with psychotic disorders and examines the effect of employment status on this association.

Method

This cross-sectional study involved people with a psychotic disorder. SR was measured using the WHO-DAS, divided into Daily Functioning (DF) and Social Functioning (SF) scales. FR was measured using the BRIEF-A and the TOL. Employment status was categorized into Non-active, Otherwise Active, and Active. The Likelihood-ratio Test (LRT) was used for model selection.

Results

Data from 251 participants (mean age 41.5) showed that the BRIEF-A affected both DF and SF, while the TOL only affected DF. Only being Otherwise Active influenced DF. Employment status had no influence on SF. Being Otherwise Active positively influenced perceived disabilities in Daily Functioning.

Conclusion

Measuring executive functions using both performance-based and self-report measures is important. Both measures are associated differently with perceived disabilities in daily and social functioning. Being a volunteer or looking for a job positively influences perceived disabilities in Daily Functioning.

Aberrant information flow within resting-state triple network model in schizophrenia-An EEG effective connectivity study

Schizophrenia is a psychiatric disorder with heterogeneous clinical manifestations and complex aetiology. Notably, the triple-network model proposes an interesting framework for investigating abnormal neurocircuit activity at rest in schizophrenia. The present study on 30 chronic schizophrenia individuals and 30 controls aimed to explore the differences in EEG resting state effective connectivity within a triple-network model using source-localization-based Directed Transfer Function. Our findings revealed multiband effective connectivity disturbances within default mode (DMN), central executive (CEN), and salience (SN) networks in schizophrenia. The most significant difference was manifested in a global DMN hyperconnectivity, accompanied by low-band hyperconnectivity and high-band hypoconnectivity in CEN, along with the aberrant information flows in SN. In conclusion, our study presents novel insights into schizophrenia neuropathology, with a particular emphasis on the reversed directionality in information flows between hubs of SN, DMN, and CEN. This may be suggested as a promising biomarker of schizophrenia.

Prevalence and associations of fatigue in psychosis: A systematic review and meta-analysis

BACKGROUND

There is increasing interest in fatigue in people with psychotic illnesses. This systematic review and meta-analysis reviewed the evidence concerning the prevalence of fatigue and associated factors in adults with psychotic illnesses.

METHODS

Embase, PsycINFO, Medline and CINAHL were systematically searched for articles in English published between January 1946 to 9 October 2023. Inclusion criteria was 'fatigue' in adults (≥18 years old) with a confirmed ICD11 or DSM5 diagnosis of a psychotic disorder. Risk of bias was assessed with the JBI and the Newcastle-Ottawa Scale. Pooled proportions for fatigue with 95 % CI were calculated using random effects models. Heterogeneity was assessed using Cochran's Q and I2 statistic and Egger's tests were conducted for publication bias.

RESULTS

A total of 57 articles met the inclusion criteria and 7 articles (n = 1161 participants) were included for the meta-analysis of fatigue. Fatigue prevalence was 55 % (95 % CI: 37-71 %, I2 = 94 %). A sensitivity analysis of the 6 studies using a valid scale (n = 711 participants) found a fatigue proportion of 59 % (95 % CI: 41-76, I2 = 93 %). Eighteen studies (n = 4569 participants) were included for an analysis exploring the prevalence of antipsychotic-related fatigue, which was 20.5 % (95 % CI: 11-34 %). We found no significant difference in antipsychotic-related fatigue between studies using a valid scale (27 %, 95 % CI: 14-46, k = 7) and studies using a clinical interview (17 %, 95 % CI: 7-35 %, k = 11) p = 0.302. An Egger's test indicated no publication bias. Quality assessments for included studies revealed that 16 % were at low risk of bias, 9 % at high risk and 75 % at moderate risk. Reported associations with fatigue included sex, age, antipsychotics, distress and depression, sleep, and some negative symptoms.

CONCLUSIONS

Our study revealed that a majority of people with psychosis experience fatigue. Antipsychotics, sex, and functioning may contribute to tiredness symptoms, but further research is needed.

Cortisol in schizophrenia spectrum disorders: A comprehensive meta-analysis

Schizophrenia spectrum disorders (SSD) are characterized by alterations in cortisol levels across various parameters, including stress reactivity, hair cortisol, and baseline levels, which may be influenced by antipsychotic treatment. To provide a comprehensive overview of cortisol dysregulation in SSD, we conducted meta-analyses assessing (1) the effects of antipsychotic treatment in SSD patients, and additionally comparing cortisol in SSD patients versus healthy controls (HC) (2) following stress induction (metabolic, physiological, psychological stressors), (3) in hair and (4) baseline levels. Systematic literature searches in PubMed, Web of Science, and PsycINFO (November 2024) identified 121 studies (9049 SSD patients) for inclusion. Meta-analytic results revealed that antipsychotic treatment significantly reduced cortisol levels in SSD (k = 16, g = -0.480, 95 % CI [-0.818, -0.142], p = 0.005). Additionally, compared to HC, SSD was associated with reduced cortisol suppression following dexamethasone exposure (k = 9, g = 0.299, 95 % CI [0.091, 0.507], p = 0.005) and with elevated baseline cortisol levels in the morning (k = 71, g = 0.38, 95 % CI [0.210, 0.546], p < 0.001) and evening (k = 11, g = 0.368, 95 % CI [0.076, 0.661], p = 0.014). However, there were no significant group differences in afternoon baseline cortisol, hair cortisol or cortisol reactivity to stress (p > 0.05). These findings offer a detailed understanding of cortisol alterations in SSD and improve our understanding of HPA axis dysregulation in SSD.

The long-term effects of a 24-week outdoor exercise program in persons with schizophrenia: Results of a 12-week follow-up period

This study aims to examine the long-term mental and physical health benefits of a 24-week outdoor exercise program after a 12-week follow-up. Forty-seven outpatients with schizophrenia completed a 24-week supervised exercise program twice a week, of whom forty-six were assessed after the follow-up period. Demographic and clinical measures were collected. Physical health was evaluated using anthropometric measures, six minutes walk test, Eurofit and accelerometer. Mental health was evaluated using Rosenberg Self-Esteem scale, Behavioural Exercise Regulations Questionnaire and World Health Organization Quality of Life Scale - Brief Version questionnaires. Participants were assessed at baseline, post-intervention and 12-week follow up. After follow-up, there were significant differences in time, between groups and in time*group in six minutes walk test. Previously observed improvements in functional exercise capacity were lost by 12-week. Flexibility scores were maintained during intervention but worsened significantly by 12-week. On the other hand, participants reported significant improvements in quality of life - physical domain by 12-week. Moderate-to-vigorous physical activity decreased and sedentary behaviour and number of flamingo errors increased but failed to achieve statistical significance. Persons with schizophrenia will lost physical health benefits previously achieved during an outdoor exercise program when supervised exercise cease.

Disorganization in individuals at clinical high risk for psychosis: psychopathology and treatment response

Disorganization is a nuclear dimension of psychosis, especially in schizophrenia. Despite its relevant association with poor prognosis and negative outcomes, it is still under-investigated compared to positive and negative symptoms, in particular at the onset of illness. This study explored disorganization in youth at Clinical High Risk for Psychosis (CHR-P) over a 2-year period. A sample of 180 CHR-P participants (50% males; 51.1% with baseline second-generation antipsychotic medication) recruited within a specialized CHR-P service completed the Positive and Negative Syndrome Scale (PANSS) and the Global Assessment of Functioning (GAF) scale. Across the follow-up, we examined key associations of disorganization with other domains of psychopathology, functioning, and treatment response using Spearman's rank correlation coefficients and linear regression analyses. Our results showed a significant longitudinal reduction in disorganization severity levels across the follow-up. This decrease was significantly associated with improvements in negative symptoms and daily functioning, with a shorter duration of untreated psychiatric symptoms, and with baseline equivalent dose of antipsychotic medication. No significant longitudinal associations with other treatment component of the PARMS program were found. Our findings suggest a longitudinal improvement in disorganization dimension in CHR-P individuals, especially in the context of early interventions targeting reduction in the duration of untreated psychiatric symptoms and favoring a prompt antipsychotic therapy.

Prediction of treatment response in drug-naïve schizophrenia patients from the perspective of targeted metabolomics

BACKGROUND

Schizophrenia (SZ) is a severe and chronic mental illness affecting approximately 1 % of the global population. Although antipsychotic medications can alleviate some symptoms, 20--30 % of patients exhibit resistance to available treatments. Therefore, identifying objective biomarkers related to treatment efficacy is crucial.

METHODS

A total of 56 drug-naïve SZ patients were recruited, and after 8 weeks of antipsychotic medication, they were classified as treatment responders (30) and non-responders (26) based on the improvement of their symptoms. Baseline plasma metabolites were measured by targeted metabolomics Biocrates MxP® Quant 500 Kit.

RESULTS

A total of 271 metabolites were identified, among which 31 exhibited significant differences between responders and non-responders, including phosphatidylcholine (PC) (14), sphingomyelin (8), ceramide (6), cholesteryl ester (2), and sarcosine (1), which were mainly concentrated in the sphingolipid metabolic pathway. Notably, key differential metabolites included phosphatidylcholine, sphingomyelin, and ceramide, which were predominantly enriched in the sphingolipid metabolism pathway. Through logistic regression analysis, sarcosine, PC aa C28:1, PC ae C34:2, and PC ae C36:3 emerged as significant predictors, yielding a combined area under the curve (AUC) of 0.877 for effectively distinguishing treatment responders from non-responders.

CONCLUSION

Our findings suggest that the combination of sarcosine, PC aa C28:1, PC ae C34:2, and PC ae C36:3 could serve as biomarkers for prediction of treatment response in patients with drug-naïve SZ.

The associations of negative and disorganization symptoms with verbal fluency in schizophrenia: the mediation effect of processing speed and cognitive flexibility

BACKGROUND

Psychopathological symptoms appear important for cognitive functions in schizophrenia. Nevertheless, the factors and their impact on relationships between negative or disorganization symptoms and verbal fluency are still debatable. The preliminary objective of the study was to compare verbal fluency, including clustering and switching as cognitive strategies, executive functions, and processing speed between individuals with schizophrenia (SZ) and healthy controls (HC). The main aim of the study was to investigate mediation models and identify whether relationships between negative and disorganization symptoms and verbal fluency in schizophrenia are mediated by cognitive flexibility and processing speed.

METHODS

Semantic (animal and fruit) and phonemic (letter k and letter f) fluency tasks, the Berg Card Sorting Test (BCST), and the Color Trails Test (CTT) were administered in the SZ group (n = 108) and a matched HC group (n = 108). The Positive and Negative Syndrome Scale (PANSS) was applied to measure psychopathological symptoms in schizophrenia patients.

RESULTS

SZ produced fewer words, had larger cluster size, and fewer switches in semantic fluency than HC. Moreover, the SZ group had longer completion time in CTT 1 and CTT 2 and higher percent of perseverative and non-perseverative errors in BCST than HC. Three mediation models demonstrated good fit indices, suggesting that processing speed and cognitive flexibility were significant mediators for relationships between: (1) psychopathological symptoms and productivity or semantic clustering in animal fluency; (2) negative symptoms and productivity in semantic or phonemic fluency; and (3) disorganization symptoms and productivity in semantic fluency.

CONCLUSIONS

Individuals with schizophrenia are characterized by a specific performance profile on verbal fluency tasks. They manifest poor productivity and problems using cognitive strategies for semantic fluency. Referring to executive functioning, schizophrenia patients exhibit decreased cognitive flexibility, problem-solving, and formulating concepts, as well as slow processing speed. It was found that processing speed and cognitive flexibility may be understood as the neuropsychological mechanisms modifying the relationships between negative symptoms, disorganization symptoms, and semantic and phonemic fluency. Therefore, these results provide a foundation for including cognitive flexibility and processing speed in cognitive remediation for schizophrenia patients.

Therapeutic efficacy of transcranial direct current stimulation in treating auditory hallucinations in schizophrenia: A meta-analysis

BACKGROUND

Schizophrenia is a chronic psychiatric condition with complex symptomatology, including debilitating auditory hallucinations. Transcranial direct current stimulation (tDCS) has been explored as an adjunctive treatment to alleviate such symptoms.

AIM

To evaluate the therapeutic efficacy of tDCS in schizophrenia.

METHODS

Adhering to PRISMA guidelines, we systematically searched PubMed, Embase, Web of Science, and the Cochrane Library on September 19, 2023, for randomized controlled trials examining the efficacy of tDCS in schizophrenia, with no language or time restrictions. We included studies that compared tDCS with a control condition and reported clinically relevant outcomes. Data extraction and quality assessments were performed by independent evaluators using the Cochrane Collaboration's risk of bias tool. Statistical heterogeneity was evaluated, and a random-effects model was applied due to moderate heterogeneity (I 2 = 41.3%).

RESULTS

Nine studies comprising 425 participants (tDCS group: 219, control group: 206) were included. The meta-analysis demonstrated a significant reduction in auditory hallucination scores following tDCS treatment (weighted mean difference: -2.18, 95% confidence interval: -4.0 to -0.29, P < 0.01). Sensitivity analysis confirmed the robustness of the results, with no significant influence from individual studies. Additionally, publication bias was not detected, supporting the reliability and generalizability of the findings. These results underscore the efficacy of tDCS as a therapeutic intervention for auditory hallucinations in schizophrenia.

CONCLUSION

tDCS significantly reduces auditory hallucinations in schizophrenia, suggesting its potential as an effective adjunctive treatment for managing this disabling symptom. The findings highlight the practical significance of tDCS in clinical settings, particularly for patients with treatment-resistant auditory hallucinations.

Large-scale effects of prenatal inflammation and early life circadian disruption in mice: Implications for neurodevelopmental disorders

Around 80 % of individuals with neurodevelopmental disorders such as schizophrenia and autism spectrum disorders experience disruptions in sleep/circadian rhythms. We explored whether environmental circadian disruption interacts with prenatal infection, a risk factor for neurodevelopmental disorders, to induce sex-specific deficits in mice. A maternal immune activation (MIA) protocol was used by injecting pregnant mice with viral mimic poly IC or saline at E9.5. Juvenile/adolescent male and female offspring (3-7 weeks old) were then subjected to a standard light:dark cycle (12:12LD) or to constant light (LL). Significant interactions between treatment (MIA, control) and lighting (12:12LD, LL) were evident in behaviors related to cognition, anxiety, and sociability. This pattern persisted in our RNA sequencing analysis of the dorsal hippocampus, where poly IC exposure resulted in numerous differentially expressed genes (DEGs) in males, while exposure to both poly IC and LL led to a marked reduction in DEGs. Through WGCNA analysis, many significant gene modules were found to be positively associated with poly IC (vs. saline) and LL (vs. LD) in males (fewer in females). Many of the identified hub-bottleneck genes were homologous to human genes associated with sleep/circadian rhythms and neurodevelopmental disorders as revealed by GWA studies. The MIA- and LL-associated modules were enriched in microglia gene signatures, which was paralleled by trends of effects of each of the factors on microglia morphology. In conclusion, in a mouse model of prenatal infection, circadian disruption induced by LL during adolescence acts as a modulator of the effects of MIA at behavioral, cellular, and molecular levels.

The Insulin-like Growth Factor Family as a Potential Peripheral Biomarker in Psychiatric Disorders: A Systematic Review

Psychiatric disorders (PDs), including schizophrenia (SZ), major depressive disorder (MDD), bipolar disorder (BD), autism spectrum disorder (ASD), among other disorders, represent a significant global health burden. Despite advancements in understanding their biological mechanisms, there is still no reliable objective and reliable biomarker; therefore, diagnosis remains largely reliant on subjective clinical assessments. Peripheral biomarkers in plasma or serum are interesting due to their accessibility, low cost, and potential to reflect central nervous system processes. Among these, the insulin-like growth factor (IGF) family, IGF-1, IGF-2, and IGF-binding proteins (IGFBPs), has gained attention for its roles in neuroplasticity, cognition, and neuroprotection, as well as for their capability to cross the blood-brain barrier. This review evaluates the evidence for IGF family alterations in PDs, with special focus on SZ, MDD, and BD, while also addressing other PDs covering almost 40 years of history. In SZ patients, IGF-1 alterations have been linked to metabolic dysregulation, treatment response, and hypothalamic-pituitary-adrenal axis dysfunction. In MDD patients, IGF-1 appears to compensate for impaired neurogenesis, although findings are inconsistent. Emerging studies on IGF-2 and IGFBPs suggest potential roles across PDs. While promising, heterogeneity among studies and methodological limitations highlights the need for further research to validate IGFs as reliable psychiatric biomarkers.

Involvement of virus infections and antiviral agents in schizophrenia

BACKGROUND

Schizophrenia is a chronic and complex mental disorder resulting from interactions between cumulative and synergistic genetic and environmental factors. Viral infection during the prenatal stage constitutes one of the most relevant risk factors for the development of schizophrenia later in adulthood.

METHODS

A narrative review was conducted to explore the link between viral infections and schizophrenia, as well as the neuropsychiatric effects of antiviral drugs, particularly in the context of this specific mental condition. Literature searches were performed using the PubMed, Scopus, and Web of Science databases.

RESULTS

Several viral infections, such as herpesviruses, influenza virus, Borna disease virus, and coronaviruses, can directly or indirectly disrupt normal fetal brain development by modifying gene expression in the maternal immune system, thereby contributing to the pathophysiological symptoms of schizophrenia. In addition, neuropsychiatric effects caused by antiviral drugs are frequent and represent significant adverse outcomes for viral treatment.

CONCLUSIONS

Epidemiological evidence suggests a potential relationship between viruses and schizophrenia. Increases in inflammatory cytokine levels and changes in the expression of key genes observed in several viral infections may constitute potential links between these viral infections and schizophrenia. Furthermore, antivirals may affect the central nervous system, although for most drugs, their mechanisms of action are still unclear, and a strong relationship between antivirals and schizophrenia has not yet been established.

Functional Connectivity in Chronic Schizophrenia: An EEG Resting-State Study with Corrected Imaginary Phase-Locking

Schizophrenia is a complex disorder characterized by altered brain functional connectivity, detectable during both task and resting state conditions using different neuroimaging methods. To this day, electroencephalography (EEG) studies have reported inconsistent results, showing both hyper- and hypo-connectivity with diverse topographical distributions. Interpretation of these findings is complicated by volume-conduction effects, where local brain activity fluctuations project simultaneously to distant scalp regions (zero-phase lag), inducing spurious inter-electrode correlations.

AIM

In the present study, we explored the network dynamics of schizophrenia using a novel functional connectivity metric-corrected imaginary phase locking value (ciPLV)-which is insensitive to changes in amplitude as well as interactions at zero-phase lag. This method, which is less prone to volume conduction effects, provides a more reliable estimate of sensor-space functional network connectivity in schizophrenia.

METHODS

We employed a cross-sectional design, utilizing resting state EEG recordings from two adult groups: individuals diagnosed with chronic schizophrenia (n = 30) and a control group of healthy participants (n = 30), all aged between 18 and 55 years old.

RESULTS

Our observations revealed that schizophrenia is characterized by a prevalence of excess theta (4-8 Hz) power localized to centroparietal electrodes. This was accompanied by significant alterations in inter- and intra-hemispheric functional network connectivity patterns, mainly between frontotemporal regions within the theta band and frontoparietal regions within beta/gamma bands.

CONCLUSIONS

Our findings suggest that patients with schizophrenia demonstrate long-range electrophysiological connectivity abnormalities that are independent of spectral power (i.e., volume conduction). Overall, distinct hemispheric differences were present in frontotemporo-parietal networks in theta and beta/gamma bands. While preliminary, these alterations could be promising new candidate biomarkers of chronic schizophrenia.

Quantitative analysis of literature on diagnostic biomarkers of Schizophrenia: revealing research hotspots and future prospects

BACKGROUND

Schizophrenia (SCZ) is a complex mental disorder characterized by a wide range of symptoms and cognitive impairments. The search for reliable biomarkers for SCZ has gained increasing attention in recent years, as they hold the potential to improve early diagnosis and intervention strategies. To understand the research trends and collaborations in this field, a comprehensive Bibliometric analysis of SCZ and biomarkers research was conducted.

METHODS

A systematic search of the Web of Science Core Collection was performed to retrieve relevant articles published from January 2000 to July 2023. The search focused on SCZ and biomarkers. Bibliometric tools, including CiteSpace, VOSviewer, and R package Bibliometrix, were utilized to perform data extraction, quantitative analysis, and visualization.

RESULTS

The search focused on SCZ and biomarkers, and a total of 2935 articles were included in the analysis. The analysis revealed a gradual increase in the number of publications related to SCZ and biomarkers over the years, indicating a growing research focus in this area. Collaboration and research activity were found to be concentrated in the United States and Western European countries. Among the top ten most active journals, "Schizophrenia Research" emerged as the journal with the highest number of publications and citations related to SCZ and biomarkers. Recent studies published in this journal have highlighted the potential use of facial expressions as a diagnostic biomarker for SCZ, suggesting that facial expression analysis using big data may hold promise for future diagnosis and interventions. Furthermore, the analysis of key research keywords identified inflammatory factors, DNA methylation changes, and glutamate alterations as potential biomarkers for SCZ diagnosis.

CONCLUSION

This Bibliometric analysis provides valuable insights into the current state of research on SCZ and biomarkers. The identification of reliable biomarkers for SCZ could have significant implications for early diagnosis and interventions, potentially leading to improved outcomes for individuals affected by this challenging mental disorder. Further research and collaborations in this field are encouraged to advance our understanding of SCZ and enhance diagnostic and therapeutic approaches.

Efficacy of Magnetic Seizure Therapy in Patients with Schizophrenia and Combined fMRI-EEG to Explore the Regulatory Mechanisms of Brain Networks

Background

Magnetic Seizure Therapy (MST) is an emerging psychiatric physical therapy in recent years, and the MST technique induces seizures by stimulating the local cortex. Numerous studies have shown that compared to electroconvulsive therapy (ECT), magnetic shock therapy (MST) has relatively little effect on cognitive function, and thus has certain advantages in clinical application. However, as far as magnetic shock therapy itself is concerned, there are few studies specifically focusing on its efficacy in depth, and the mechanism of MST in treating schizophrenia is still unclear.

Methods

This study centered on the key question of "the efficacy of magnetic stunning therapy for patients with schizophrenia and the combined fMRI-EEG to explore the regulatory mechanisms of brain networks". The study protocol describes our interventional clinical trial aimed at developing magnetic convulsive therapy as an effective and safe treatment for SCZ. The study population consisted of SCZ patients and healthy controls (Hc). Clinical symptoms, cognitive function, EEG and fMRI data were collected from the patient group at baseline, post-treatment and follow-up phases. We systematically assessed the clinical features and cognitive functions of the patients, combined with EEG and fMRI indexes to explore the brain network connectivity abnormalities in SCZ patients, and jointly explored the neuroimaging mechanisms in SCZ patients.

Conclusion

Positive results from this trial may have a direct and significant impact on patients with SCZ. Once the MST demonstrates significant antipsychotic efficacy with high perceived safety, it will have significant implications for clinical practice. Brain network abnormality may be one of the core pathological mechanisms of SCZ. Therefore, by combining neurophysiological imaging techniques to scientifically verify the abnormality of SCZ brain network, the elucidation of this issue can help to further reveal the pathological mechanism of SCZ and provide a scientific basis for the effective and precise treatment of the disease.

Trial Registration

ChiCTR2000038361 Registered on September 21, 2020.

A new 2-hit model combining serine racemase deletion and maternal separation displays behavioral and cognitive deficits associated with schizophrenia

Schizophrenia (SCZ) is a multifactorial psychotic disorder characterized by positive and negative symptoms as well as cognitive impairments. To advance the current treatments, it is important to improve animal models by considering the multifactorial etiology, thus by combining different risk factors. The objective of our study was to explore in a new mouse model, the impact of genetic deletion of serine racemase (genetic vulnerability) combined with an early stress factor induced by maternal separation (early environmental exposure) in the context of SCZ development. The face validity of the model was assessed through a wide range of behavioral experiments. The 2-hit mice displayed an increased locomotor activity mimicking positive symptoms, working memory impairment, cognitive deficits and recognition memory alterations, which could reflect neophobia. This new multifactorial model therefore presents an interesting phenotype for modelling animal model with partial behavioral and cognitive deficits associated with SCZ.

Aberrant Functional Connectivity and Brain Network Organization in High-Schizotypy Individuals: An Electroencephalography Study

BACKGROUND AND HYPOTHESIS

Oscillatory synchrony plays a crucial role in establishing functional connectivity across distinct brain regions. Within the realm of schizophrenia, suggested to be a neuropsychiatric disconnection syndrome, discernible aberrations arise in the organization of brain networks. We aim to investigate whether the resting-state functional network is already altered in healthy individuals with high schizotypy traits, highlighting the pivotal influence of brain rhythms in driving brain network alterations.

STUDY DESIGN

Two-minute resting-state electroencephalography recordings were conducted on healthy participants with low and high schizotypy scores. Subsequently, spectral Granger causality was used to compute functional connectivity in theta, alpha, beta, and gamma frequency bands, and graph theory metrics were employed to assess global and local brain network features.

STUDY RESULTS

Results highlighted that high-schizotypy individuals exhibit a lower local efficiency in theta and alpha frequencies and a decreased global efficiency across theta, alpha, and beta frequencies. Moreover, high schizotypy is characterized by a lower nodes' centrality and a frequency-specific decrease of functional connectivity, with a reduced top-down connectivity mostly in slower frequencies and a diminished bottom-up connectivity in faster rhythms.

CONCLUSIONS

These results show that healthy individuals with a higher risk of developing psychosis exhibit a less efficient functional brain organization, coupled with a systematic decrease in functional connectivity impacting both bottom-up and top-down processing. These frequency-specific network alterations provide robust support for the dimensional model of schizophrenia, highlighting distinctive neurophysiological signatures in high-schizotypy individuals.

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.

Transcranial direct current stimulation (tDCS) enhances cognitive function in schizophrenia: A randomized double-blind sham-controlled trial

This study aimed to examine the cognitive effects of tDCS and the subjective cognitive improvement perceived by patients with schizophrenia. A total of 173 outpatients diagnosed with schizophrenia were recruited for this double-blind, randomized, placebo-controlled trial. Two different stimulation modes were applied: 2 mA 20 minutes active tDCS and sham tDCS. Ten daily sessions over 10 consecutive weekdays were applied, using a bifrontal montage (F3/F4). The Positive and Negative Syndrome Scale for Schizophrenia and the MATRICS Consensus Cognitive Battery (MCCB) were administered at baseline. The MCCB and a scale designed for measuring subjective cognitive improvement were administered to evaluate the outcomes. Post hoc comparisons revealed significant effects between the two types of interventions in Working Memory (EMM difference = 2.716, p < .001) and Neurocognition (EMM difference = 1.289, p = .007. Chi-squared tests demonstrated a significant association between subjective improvement and the treatment group, χ² (2) = 10.413, p = .005, Cramer's V = 0.295. A higher proportion of patients in active tDCS (68.6%) reported cognitive improvement compared to sham tDCS (31.4%). We concluded that tDCS can enhance cognition and generate a satisfactory perception of cognitive improvement in patients with schizophrenia.

Impact of age of onset on the course of chronic schizophrenia: factors associated with first hospitalization in a large-scale cross-sectional study

This study aims to identify the factors influencing the age of first hospitalization in patients with chronic schizophrenia, focusing on clinical features and blood parameters. A total of 1271 patients diagnosed with chronic schizophrenia were recruited from 17 psychiatric hospitals across China. Demographic and clinical data, including age of first hospitalization, were collected. The study also included assessments of psychiatric symptoms, duration of untreated psychosis (DUP), and various blood parameters. Statistical analyses were conducted to examine the relationships between these factors and the age of first hospitalization. The average age of first hospitalization was 28.07 ± 9.993 years. Single patients and those with a family history of mental illness were hospitalized at a younger age. Patients with suicidal ideation or behavior also had an earlier hospitalization age compared to those without such history. Regression analysis revealed that marital status (single), family history of mental illness, and suicide ideation or behavior were significant risk factors for earlier hospitalization age. Conversely, DUP, total protein (TP), and low-density lipoprotein (LDL) levels were positively correlated with the age of first hospitalization, while antipsychotic medication dosage and albumin (ALB) levels were negatively correlated. The study identifies significant demographic, clinical, and biochemical factors associated with the age of first hospitalization in chronic schizophrenia patients in China. These findings underscore the importance of early intervention and targeted support for high-risk groups to improve treatment outcomes.

Correlation analyse between thyroid hormone levels and severity of schizophrenia symptoms

BACKGROUND

The imbalance of hormone levels in the body is closely related to the occurrence and progression of schizophrenia, especially thyroid hormones.

AIM

To study the relationship between triiodothyronine (T3), thyroxine (T4), free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH) and schizophrenia.

METHODS

In this study, 100 schizophrenia patients were selected from our hospital between April 2022 and April 2024. Their clinical data were analyzed retrospectively. Based on the Positive and Negative Syndrome Scale (PANSS) score, patients were divided into mild (1-3 points, n = 39), moderate (4 points, n = 45), and severe groups (5-7 points, n = 16). Additionally, 55 healthy individuals served as a control group. Venous blood samples were collected to measure T3, T4, FT3, FT4, TSH, and cortisol concentrations, analyzing their relationship with PANSS scores.

RESULTS

The serum levels of T3, FT3, FT4, TSH and cortisol in the schizophrenia group were lower than those in the control group (P < 0.05). With the increase of the severity of the disease, the concentrations of T3 and T4 decreased, while the concentrations of TSH and cortisol increased (P < 0.05). The concentrations of TSH and cortisol were positively correlated with the PANSS score, while T3 and T4 were negatively correlated with the PANSS score (P < 0.05). The receiver operating characteristic curve results showed that T3, T4, TSH, and cortisol had good efficacy in the diagnosis of schizophrenia. Logistic results showed that decreased T3 level, decreased T4 level, decreased TSH level and increased cortisol level may be independent risk factors for schizophrenia.

CONCLUSION

Thyroid hormone levels are associated with the severity of schizophrenia symptoms, which can provide new solutions for the diagnosis and treatment of schizophrenia.

Evaluation of the impact of refined nursing care on schizophrenia patients

This study evaluates the impact of refined nursing interventions on patients with schizophrenia, focusing on disease severity, cognitive function, medication adherence, quality of life, and medication-related complications. The aim is to provide evidence for enhancing future clinical treatments. From January 2022 to January 2024, 201 schizophrenia patients were enrolled based on specific inclusion and exclusion criteria. Patients were allocated into 2 groups using propensity score matching: an experimental group that received refined nursing care and a control group that received routine care. Outcome measures included Positive and Negative Syndrome Scale scores, cognitive assessments (Mini-Mental State Examination and Nurses' Observation Scale for Inpatient Evaluation), medication adherence, quality of life, relapse rates, and medication-related side effects. After propensity score matching, baseline characteristics of the experimental and control groups were comparable. Following nursing interventions, the experimental group demonstrated significant improvements in Positive and Negative Syndrome Scale scores, cognitive assessments (Mini-Mental State Examination and Nurses' Observation Scale for Inpatient Evaluation), medication adherence, and quality of life compared to the control group. The experimental group also showed lower relapse rates and fewer medication side effects, confirming the enhanced effectiveness of refined nursing interventions. Refined nursing care significantly improved disease outcomes, cognitive function, medication adherence, and quality of life in schizophrenia patients, while reducing relapse rates and medication-related complications, highlighting its clinical value in psychiatric care.

Effectiveness of positive allosteric modulators of metabotropic glutamate receptor 2/3 (mGluR2/3) in animal models of schizophrenia

Schizophrenia (SZ) is a deleterious brain disorder characterised by its heterogeneity and complex symptomatology consisting of positive, negative and cognitive deficits. Current antipsychotic drugs ameliorate the positive symptomatology, but are inefficient in treating the negative symptomatology and cognitive deficits. The neurodevelopmental glutamate hypothesis of SZ has opened new avenues in the development of drugs targeting the glutamatergic system. One of these new therapies involves the positive allosteric modulators (PAMs) of metabotropic glutamate receptors, mainly types 2/3 (mGluR2/3). mGluR2/3 PAMs are selective for the receptor, present high tolerability and can modulate the activity of the receptor for long periods. There is not much research in clinical trials regarding mGluR2/3 PAMs. However, several lines of evidence from animal models have indicated the efficiency of mGluR2/3 PAMs. In this review, focusing on in vivo animal studies, we will specifically discuss the utilization of SZ animal models and the various methods employed to assess animal behaviour before summarising the evidence obtained to date in the field of mGluR2/3 PAMs. By doing so, we aim to deepen our understanding of the underlying mechanisms and the potential efficiency of mGluR2/3 PAMs in treating SZ. Overall, mGluR2/3 PAMs have demonstrated efficiency in attenuating SZ-like behavioural and molecular deficits in animal models and could be useful for the early management of the disorder or to treat specific subsets of patients.

OBF-Psychiatric, a motor activity dataset of patients diagnosed with major depression, schizophrenia, and ADHD

Mental health is vital to human well-being, and prevention strategies to address mental illness have a significant impact on the burden of disease and quality of life. With the recent developments in body-worn sensors, it is now possible to continuously collect data that can be used to gain insights into mental health states. This has the potential to optimize psychiatric assessment, thereby improving patient experiences and quality of life. However, access to high-quality medical data for research purposes is limited, especially regarding diagnosed psychiatric patients. To this extent, we present the OBF-Psychiatric dataset which comprises motor activity recordings of patients with bipolar and unipolar major depression, schizophrenia, and ADHD (attention deficit hyperactivity disorder). The dataset also contains data from a clinical sample diagnosed with various mood and anxiety disorders, as well as a healthy control group, making it suitable for building machine learning models and other analytical tools. It contains recordings from 162 individuals totalling 1565 days worth of motor activity data with a mean of 9.6 days per individual.

Pharmacovigilance of drug-drug interactions: A pharmacokinetic study on the combined oral administration of lurasidone and clozapine in rats by using LC-MS/MS

In recent years, the expanding array of psychotropic medications has led to an increase in drug-drug interactions, particularly with combinations of different antipsychotics or psychotropic medications in clinical practice. However, the potential pharmacokinetic interactions between Lurasidone and Clozapine have not been extensively studied. Thus, this study aims to investigate these potential interactions by analyzing their pharmacokinetics in rat plasma after single oral administrations using developed LC-MS/MS methods. The study revealed notable changes in Lurasidone's pharmacokinetic parameters between single and combination administrations. Specifically, there were significant reductions in t1/2 and Vd by 3.3 and 1.5-fold (p < 0.05) respectively, while Cmax and AUC0-t proved a significant increase by 1.8 and 1.6-fold (p < 0.05) respectively following the combination administration. Furthermore, separate co-administration markedly decreased Clozapine's Cmax and AUC 0-t by 1.6 and 1.3-fold (p < 0.05) respectively, after the combination administration. Moreover, the AUC ratio for Lurasidone was 0.2, indicating a diminished therapeutic effect, whereas the AUC ratio for Clozapine suggested an elevated risk of adverse effects. These findings confirm the presence of drug-drug interactions between Lurasidone and Clozapine, suggesting potential implications for treatment efficacy. Recommendations for future clinical research include conducting pharmacodynamic studies to evaluate the impact of Lurasidone and Clozapine combination therapy. This underscores the importance of thoroughly assessing these interactions for clinical relevance and provides a scientific foundation for future evaluations of this drug combination.

The relationship between perceived family support and subclinical positive symptoms of psychosis among Black college students

AIM

Black individuals in the Unites States endure compounded and unique experiences of discrimination and structural racism that may not be as overtly evident in other countries. These distinctive forms of discrimination and racism can impact the mental health of Black individuals in the Unites States, in this case, their risk for psychosis. Adolescence and early adulthood are vulnerable periods in life where mental illness typically begins to manifest. Understanding the factors contributing to an increased likelihood of specific mental illnesses, such as psychosis, among youth in these vulnerable periods can inform intervention development. This is particularly important for those from minoritized backgrounds Unites States; this group is especially important to study given that Black American youth tend to experience higher psychosis rates and different symptom presentations than non-Black groups.

METHODS

This study examined the associations between perceived family support, a critical environmental factor known to be associated with full-psychosis, and attenuated positive symptoms and distress levels in a sample of 155 Black students from a Historically Black College and University (HBCU). Participants completed the Prodromal Questionnaire-Brief that assessed psychosis risk and the Family Environment Scale that assessed three dimensions of family support (family cohesion, expressiveness, and conflict).

RESULTS AND CONCLUSION

Positive symptom intensity (r = .30, p < .001) and distress (r = .34, p < .001) were significantly associated with higher family conflict for Black individuals in the Unites States. The findings inform novel intervention targets for psychoeducation and family therapy that have potential to reduce psychosis risk.

Psychomotor slowing in schizophrenia is associated with aberrant postural control

Motor abnormalities, including psychomotor slowing, are prevalent in a large proportion of individuals with schizophrenia. While postural control deficits have been observed in this population, the impact of motor abnormalities on postural stability remains unclear. This study aimed to objectively evaluate postural stability in patients with and without psychomotor slowing and healthy controls. Seventy-three schizophrenia patients with psychomotor slowing (PS; Salpêtrière Retardation Rating Scale (SRRS) ≥ 15), 25 schizophrenia patients without psychomotor slowing (non-PS; SRRS < 15), and 27 healthy controls (HC) performed four conditions on the Kistler force plate: eyes open (EO), eyes closed (EC), head reclined with eyes open (EOHR), and head reclined with eyes closed (ECHR). Larger sway areas and higher Root Mean Square (RMS) values indicate lower postural stability, while a lower Complexity Index (CI) reflects reduced adaptability, flexibility, and dynamic functioning of postural control. PS exhibited larger sway areas and higher RMS compared to the other groups. Both PS and non-PS showed reduced complexity in postural control compared to healthy controls, without differences between the two patient groups. Reduced postural stability and complexity were associated with greater expert-rated motor abnormalities, as well as more severe negative symptoms. Additionally, lower complexity was linked to reduced physical activity levels. These findings suggest that psychomotor slowing is associated with lower postural stability, potentially reflecting impaired cerebellar function. Furthermore, the loss of complexity in postural control highlights reduced flexibility, adaptability, and efficiency in the postural control network of individuals with schizophrenia.

Pathological mechanisms of glial cell activation and neurodegenerative and neuropsychiatric disorders caused by Toxoplasma gondii infection

Toxoplasma gondii is an intracellular opportunistic parasite that exists in a latent form within the human central nervous system (CNS), even in immune-competent hosts. During acute infection, T. gondii traverses the blood-brain barrier (BBB). In the subsequent chronic infection phase, the infiltration of immune cells into the brain, driven by T. gondii infection and the formation of parasitic cysts, leads to persistent activation and proliferation of astrocytes and microglia. This process results in neuronal damages that are fatal in some cases. Through inducing systemic immune responses, T. gondii infection can dramatically alter the behavior of rodents and increase the risk of various neuropsychiatric disorders in humans. In this review, we explore some recent research progress on the major events involved in BBB disruption, glial cell activation and neuronal damage following T. gondii infection in hosts. It further discusses potential pathological mechanisms and the feasible treatment approaches for the neurodegenerative and neuropsychiatric disorders caused by T. gondii infection to extend our understanding for pathogenesis and preventive control of toxoplasmosis in humans.

Meta-analysis of the factor structure of the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS)

INTRODUCTION

The SAPS and SANS was designed to measure two broad factors, but the majority of factor analyses conducted have found substantially more dimensions. To investigate their structure a meta-analysis was conducted of SAPS and SANS factor analysis.

METHOD

A total of 42 articles reporting 55 factor analyses were retrieved from database searches (PubMed, PsychINFO) supplemented by searches of references. Reproduced correlations were calculated from retrieved factor analyses and 3 separate meta-analyses were conducted.

RESULTS

The meta-analysis of the SAPS SANS global ratings (k = 34; n = 5219) yielded a 3-factor solution including Positive Symptoms (Hallucinations and Delusions), Negative Symptoms (Affective Flattening, Alogia, Avolition/Apathy, Anhedonia/Asociality and Attentional Impairment), and Disorganization (Positive Formal Thought Disorder and Bizarre Behavior). The item analysis of the SAPS SANS combined (k = 11; n = 3146) found 4 factors, with the Negative Symptoms splitting into Affective Flattening/Alogia and Avolition/Asociality as main difference. The SANS only item analysis (k = 10; n = 2073) identified 3 factors, Affective Flattening, Avolition/Asociality, and Alogia/Inattentiveness. Importantly, our data suggests that the items Inappropriate Affect and Poverty of Content of Speech should be moved from Negative Symptoms to the Disorganization factor. Attentional Impairment shows the highest loading on Negative Symptoms but its inclusion under this dimension is conceptually unclear and it may be better considered as a non-specific domain.

CONCLUSIONS

The three factor structure of Positive Symptoms, Negative Symptoms and Disorganization accounted for most of the data. The SAPS SANS global scales are generally valid, but suggestions for a conservative revision of SAPS SANS structure, including supplementary subscales, are presented.

Cannabidiol attenuates prepulse inhibition disruption by facilitating TRPV1 and 5-HT1A receptor-mediated neurotransmission

Individuals with schizophrenia (SCZ) often present sensorimotor gating impairments that can be investigated by the prepulse inhibition test (PPI). PPI disruption can be mimicked experimentally with psychostimulants such as amphetamine and attenuated/reversed by antipsychotics. Cannabidiol (CBD), the main non-psychotomimetic component of the Cannabis sativa plant, produces antipsychotic-like effects in clinical and preclinical studies. CBD can interact with many pharmacological targets, but the mechanisms involved in its antipsychotic activity are unclear. Using amphetamine-induced PPI disruption in mice, we investigated the involvement of four CBD potential pharmacological targets (CB1, CB2 TRPV1, and 5-HT1A receptors) in its antipsychotic properties. CBD effects were blocked by the TRPV1 antagonist capsazepine and, to a greater extent, by the 5-HT1A receptor antagonist WAY100635. No effect was observed with the CB1 (AM251) or CB2 (AM630) receptor antagonists. These results corroborate findings showing the antipsychotic effects of CBD in the PPI model and indicate that they involve the participation of TRPV1 and 5-HT1A receptors.

A cross-section study of the comparison of plasma inflammatory cytokines and short-chain fatty acid in patients with depression and schizophrenia

BACKGROUND

Major depressive disorder (MDD) and schizophrenia (SCH) are common and severe mental disorders that are mainly diagnosed depending on the subjective identification by psychiatrists. Finding potential objective biomarkers that can distinguish these two diseases is still meaningful.

METHODS

In the present study, we investigate the differences in plasma inflammatory cytokines and short-chain fatty acids (SCFAs) among patients with MDD (n = 24) and SCH (n = 24), and gender- and age-matched healthy controls (HC, n = 27) and identify potential plasma biomarkers.

RESULTS

We found that the concentrations of pro-inflammatory cytokines were increased, whereas the anti-inflammatory cytokines were decreased in both MDD and SCH. Meanwhile, except for an increase in 4-Methylvaleric acid, other SCFAs with statistical differences were reduced in both MDD and SCH. Moreover, potential biomarker panels were developed that can effectively discriminate MDD from HC (AUC = 0.997), SCH from HC (AUC = 0.999), and from each other (MDD from SCH, AUC = 0.983).

CONCLUSIONS

These data suggest that alterations in plasma cytokines and SCFAs might be one of the potential features for distinguishing MDD and SCH.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2100051243, registration date: 2021/09/16.

Yoga-Based Group Intervention for Inpatients with Schizophrenia Spectrum Disorders-Feasibility, Acceptability, and Preliminary Outcomes of a Rater-Blinded Randomized Controlled Trial

BACKGROUND AND HYPOTHESIS

The efficacy of yoga as an adjunctive treatment for schizophrenia spectrum disorders (SSD) has garnered interest. While yoga may positively influence various symptom domains, further investigation is needed due to the limited number, quality, and generalizability of studies. This study assessed the feasibility and acceptability (primary outcome) of a yoga-based group intervention (YoGI) developed in a participatory approach and explored its preliminary effectiveness.

STUDY DESIGN

In addition to the primary outcomes, this preregistered randomized controlled trial examined rater-blinded general psychopathology, positive- and negative symptoms, and self-rated depression, anxiety, stress, body mindfulness, mindfulness, psychological flexibility, cognition, social functioning, quality of life, and medication regime at baseline and postintervention as secondary outcomes.

STUDY RESULTS

Fifty inpatients with SSD received either TAU (n = 25) or YoGI + TAU (n = 25) for four weeks. Outcomes showed 95% protocol adherence of YoGI, feasibility, and retention rates of 91% and 94%, respectively, and a dropout rate of 6%. ANCOVA revealed significant between-group postintervention improvements for YoGI + TAU in positive symptoms, depression, cognitive fusion, and a mindfulness subscale. Medium-to-large pre- to postintervention effects were found for body mindfulness, positive, negative, and general psychopathology, cognitive fusion, depression, anxiety, stress, quality of life, and attention in YoGI + TAU, while within-group changes were consistently smaller in TAU. No severe adverse events were reported.

CONCLUSIONS

This trial supports the feasibility and acceptability of YoGI for inpatients with SSD and provides preliminary evidence of YoGI's benefits beyond TAU. Further robust, multicentric RCTs are warranted to deepen our understanding of YoGI's therapeutic potential and inform clinical interventions for SSD.

Effects of repetitive transcranial magnetic stimulation on inhibitory control in first-episode schizophrenia: behavioral and neural mechanisms

Background

Inhibitory control deficits are a core feature of cognitive impairment in schizophrenia, associated with abnormal activation of key brain networks. Repetitive transcranial magnetic stimulation (rTMS) targeting the dorsolateral prefrontal cortex (DLPFC) may help improve inhibitory control, but its specific effects in schizophrenia remain uncertain.

Methods

This study involved 150 participants divided into Real-rTMS, Sham-rTMS, and healthy control groups. Inhibitory control was assessed using the dual-choice oddball task, and task-based functional magnetic resonance imaging (fMRI) was employed to examine neural activity. The Real-rTMS group received active stimulation over the DLPFC, and the Sham group received placebo stimulation.

Results

The Real-rTMS group exhibited significant improvements in both reaction times and accuracy compared to the Sham group, indicating enhanced inhibitory control. fMRI data showed that brain activity in regions such as the cerebellum, insula, thalamus, and prefrontal cortex was normalized in the Real-rTMS group, with activation patterns closely resembling those observed in healthy controls. Additionally, task-based fMRI revealed a restoration and further enhancement of negative activation in regions like the middle frontal gyrus and superior temporal gyrus, which helped reduce cognitive interference from irrelevant stimuli.

Conclusion

rTMS targeting the DLPFC improves inhibitory control in schizophrenia by modulating both positive and negative brain activation patterns. These findings highlight the dual mechanism through which rTMS enhances cognitive control, offering a promising intervention for cognitive deficits in schizophrenia. Future research should explore the long-term effects of this modulation on broader cognitive functions.

Current progress in understanding schizophrenia using genomics and pluripotent stem cells: A meta-analytical overview

Schizophrenia (SCZ) is a complex, heritable and polygenic neuropsychiatric disease, which disables the patients as well as decreases their life expectancy and quality of life. Common and rare variants studies on SCZ subjects have provided >100 genomic loci that hold importance in the context of SCZ pathophysiology. Transcriptomic studies from clinical samples have informed about the differentially expressed genes (DEGs) and non-coding RNAs in SCZ patients. Despite these advancements, no causative genes for SCZ were found and hence SCZ is difficult to recapitulate in animal models. In the last decade, induced Pluripotent Stem Cells (iPSCs)-based models have helped in understanding the neural phenotypes of SCZ by studying patient iPSC-derived 2D neuronal cultures and 3D brain organoids. Here, we have aimed to provide a simplistic overview of the current progress and advancements after synthesizing the enormous literature on SCZ genetics and SCZ iPSC-based models. Although further understanding of SCZ genetics and pathophysiological mechanisms using these technological advancements is required, the recent approaches have allowed to delineate important cellular mechanisms and biological pathways affected in SCZ.

Patient iPSC-derived neural progenitor cells display aberrant cell cycle control, p53, and DNA damage response protein expression in schizophrenia

BACKGROUND

Schizophrenia (SCZ) is a severe psychiatric disorder associated with alterations in early brain development. Details of underlying pathomechanisms remain unclear, despite genome and transcriptome studies providing evidence for aberrant cellular phenotypes and pathway deregulation in developing neuronal cells. However, mechanistic insight at the protein level is limited.

METHODS

Here, we investigate SCZ-specific protein expression signatures of neuronal progenitor cells (NPC) derived from patient iPSC in comparison to healthy controls using high-throughput Western Blotting (DigiWest) in a targeted proteomics approach.

RESULTS

SCZ neural progenitors displayed altered expression and phosphorylation patterns related to Wnt and MAPK signaling, protein synthesis, cell cycle regulation and DNA damage response. Consistent with impaired cell cycle control, SCZ NPCs also showed accumulation in the G2/M cell phase and reduced differentiation capacity. Furthermore, we correlated these findings with elevated p53 expression and phosphorylation levels in SCZ patient-derived cells, indicating a potential implication of p53 in hampering cell cycle progression and efficient neurodevelopment in SCZ.

CONCLUSIONS

Through targeted proteomics we demonstrate that SCZ NPC display coherent mechanistic alterations in regulation of DNA damage response, cell cycle control and p53 expression. These findings highlight the suitability of iPSC-based approaches for modeling psychiatric disorders and contribute to a better understanding of the disease mechanisms underlying SCZ, particularly during early development.

Altered intrinsic neural activity and its molecular analyses in first-episode schizophrenia with auditory verbal hallucinations

Background

Auditory verbal hallucinations (AVHs) are one of the signature positive symptoms of schizophrenia, affecting a substantial portion of patients with schizophrenia. These hallucinations seriously impact the lives of patients, resulting in a substantial social burden. Recent studies have shown a significant correlation between abnormal local brain activity and the neurobiological mechanisms of AVHs. However, it is not fully clear whether altered intrinsic brain activity in schizophrenia patients with AVHs is correlated with specific neurotransmitter systems.

Methods

We included 50 first-episode, drug-naïve schizophrenia patients with AVHs, 50 patients without AVHs (NAVHs), and 50 age- and sex-matched healthy controls (HCs). The amplitude of low-frequency fluctuation (ALFF) was utilized to explore the altered intrinsic brain activity in the AVH group. Subsequently, we spatially correlated the altered ALFF with neurotransmitter maps using JuSpace.

Results

In our study, compared to HCs, the AVH group exhibited significantly reduced ALFF in multiple brain regions, mainly including the left precuneus, bilateral supplementary motor areas, bilateral paracentral lobules, bilateral precentral gyri, and bilateral postcentral gyri. The NAVH group showed significantly reduced ALFF in the left inferior occipital gyrus, left calcarine gyrus, and left lingual gyrus compared to HCs. Furthermore, the AVH group showed higher ALFF in the right inferior frontal gyrus compared to the NAVH group. Additionally, these ALFF alterations in the AVH group were closely related to three neurotransmitters, including dopamine, serotonin and norepinephrine.

Conclusion

We link neurotransmitters to abnormal intrinsic brain activity in first-episode, drug-naïve schizophrenia patients with AVHs, contributing to a comprehensive understanding of the pathophysiological processes and treatment pathways underlying AVHs.

Efficacy of Horticultural Therapy on Positive, Negative, and Affective Symptoms in Individuals with Schizophrenia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Positive symptoms, negative symptoms, and emotional disturbances are core features of schizophrenia. Although horticultural therapy (HT) has shown promise as an adjunctive treatment, evidence supporting its effectiveness remains limited. This systematic review and meta-analysis aimed to assess the impact of HT on total symptoms, positive symptoms, negative symptoms, and emotional disturbances in individuals with schizophrenia. Methods: We conducted a search for randomized controlled trials (RCTs) published up to March 2024 across multiple databases, including PubMed, Embase, Cochrane Library, CINAHL, CEPS, CNKI, Wanfang, and Yiigle. A random-effects model was employed to calculate the standardized mean difference (SMD). Results: A total of 35 studies enrolling 2899 participants were included. Our results indicated that, in the short term (≦3 months), HT has moderate to large effect sizes on total symptoms (SMD = 0.690, 95% CI 0.463 to 0.916), positive symptoms (SMD = 0.695, 95% CI 0.038 to 1.351), negative symptoms (SMD = 0.681, 95% CI 0.395 to 0.967), depression (SMD = 0.646, 95% CI 0.334 to 0.959), and anxiety (SMD = 0.627, 95% CI 0.364 to 0.890), with more pronounced benefits for anxiety symptoms in patients with a shorter duration of illness. In the long term (>3 months), HT shows large effect sizes for total symptoms (SMD = 1.393, 95% CI 0.858 to 1.928), negative symptoms (SMD = 1.389, 95% CI 0.935 to 1.842), anxiety (SMD = 1.541, 95% CI 1.042 to 2.040), and moderate to large effect sizes for positive symptoms (SMD = 0.667, 95% CI 0.077 to 1.258) and depression (SMD = 0.707, 95% CI 0.198 to 1.217). Additionally, longer weekly treatment durations are associated with better outcomes for total symptoms and negative symptoms. Schizophrenia patients with more severe initial symptoms may be potential responders to HT. Conclusions: These findings support the efficacy of HT in improving symptoms and emotional well-being in schizophrenia patients. Further trials with more rigorous designs are warranted to confirm these benefits.

Aberrant neuronal connectivity and network activity of neurons derived from patients with idiopathic schizophrenia

Schizophrenia (SCZ) is a psychiatric disorder with a strong genetic determinant. A major hypothesis to explain disease aetiology comprises synaptic dysfunction associated with excitatory-inhibitory imbalance of synaptic transmission, ultimately contributing to impaired network oscillation and cognitive deficits associated with the disease. Here, we studied the morphological and functional properties of a highly defined co-culture of GABAergic and glutamatergic neurons derived from induced pluripotent stem cells (iPSC) from patients with idiopathic SCZ. Our results indicate upregulation of synaptic genes and increased excitatory synapse formation on GABAergic neurons in co-cultures. In parallel, we observed decreased lengths of axon initial segments, concordant with data from postmortem brains from patients with SCZ. In line with increased synapse density, patch-clamp analyses revealed markedly increased spontaneous excitatory postsynaptic currents (EPSC) recorded from GABAergic SCZ neurons. Finally, MEA recordings from neuronal networks indicate increased strength of network activity, potentially in response to altered synaptic transmission and E-I balance in the co-cultures. In conclusion, our results suggest selective deregulation of neuronal activity in SCZ samples, providing evidence for altered synapse formation and synaptic transmission as a potential base for aberrant network synchronization.

Relationship between eating attitudes, depression, and insight in schizophrenic patients with and without type 2 diabetes mellitus: a comparative study in Guangdong, China

Background

Schizophrenia, a severe mental disorder, is often complicated by Type 2 Diabetes Mellitus (T2DM), which can further impact patients' psychological health. This study investigated the differences in eating attitudes, depression, and insight between schizophrenic patients with and without comorbid T2DM and explored the correlations among these factors to provide empirical support for clinical interventions.

Methods

This case-control study was conducted in Guangdong Province, China. From December 2022 to May 2023, a total of 300 hospitalized patients with schizophrenia (92 with comorbid T2DM and 208 without T2DM) were recruited. Data were collected using the Personal Information Form, Eating Attitudes Test (EAT-26), Hamilton Depression Scale (HAMD), and Insight and Treatment Attitudes Questionnaire (ITAQ). Statistical analyses, including t-tests, ANOVA, and multiple linear regression, were performed to examine differences and predictive factors of eating attitudes among patients. This study was approved by the Ethics Committee of the Affiliated Brain Hospital of Guangzhou Medical University (approval number: 2020028), and written informed consent was obtained from all participants.

Results

Patients with schizophrenia and comorbid T2DM exhibited significantly higher risks of eating disorders (EAT-26: 12.54 ± 9.77 vs. 9.07 ± 7.90, P=0.003), more severe depression (HAMD: 14.71 ± 7.36 vs. 11.80 ± 6.04, P=0.001), and poorer insight (ITAQ: 10.46 ± 6.01 vs. 12.16 ± 6.09, P=0.025) compared to those without T2DM. Regression analysis revealed that gender, weekly exercise frequency, depression, and insight were significant predictors of eating attitudes among patients with T2DM. For patients without T2DM, weekly exercise frequency, smoking status, and insight were significant predictors.

Conclusion

Schizophrenic patients with comorbid T2DM are facing increasing risks related to eating attitudes, depression, and insight which highlight the need for targeted interventions. Regular psychological assessment and tailored support strategies might improve their mental health and quality of life. Future research should focus on longitudinal studies to clarify causal relationships and develop more effective interventions.

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.

Investigating the association between symptoms and functional activity in brain regions in schizophrenia: A cross-sectional fmri-based neuroimaging study

Schizophrenia is a persistent neurological disorder profoundly affecting cognitive, emotional, and behavioral functions, prominently characterized by delusions, hallucinations, disordered speech, and abnormal motor activity. These symptoms often present diagnostic challenges due to their overlap with other forms of psychosis. Therefore, the implementation of automated diagnostic methodologies is imperative. This research leverages Functional Magnetic Resonance Imaging (fMRI), a neuroimaging modality capable of delineating functional activations across diverse brain regions. Furthermore, the utilization of evolving machine learning techniques for fMRI data analysis has significantly progressive. Here, our study stands as a novel attempt, focusing on the comprehensive assessment of both classical and atypical symptoms of schizophrenia. We aim to uncover associated changes in brain functional activity. Our study encompasses two distinct fMRI datasets (1.5T and 3T), each comprising 34 schizophrenia patients for the 1.5T dataset and 25 schizophrenia patients for the 3T dataset, along with an equal number of healthy controls. Machine learning algorithms are applied to assess data subsets, enabling an in-depth evaluation of the current functional condition concerning symptom impact. The identified voxels contribute to determining the brain regions most influenced by each symptom, as quantified by symptom intensity. This rigorous approach has yielded various new findings while maintaining an impressive classification accuracy rate of 97 %. By elucidating variations in activation patterns across multiple brain regions in individuals with schizophrenia, this study contributes to the understanding of functional brain changes associated with the disorder. The insights gained may inform differential clinical interventions and provide a means of assessing symptom severity accurately, offering new avenues for the management of schizophrenia.

Phosphatidylserine: A comprehensive overview of synthesis, metabolism, and nutrition

Phosphatidylserine (PtdS) is classified as a glycerophospholipid and a primary anionic phospholipid and is particularly abundant in the inner leaflet of the plasma membrane in neural tissues. It is synthesized from phosphatidylcholine or phosphatidylethanolamine by exchanging the base head group with serine, and this reaction is catalyzed by PtdS synthase-1 and PtdS synthase-2 located in the endoplasmic reticulum. PtdS exposure on the outside surface of the cell is essential for eliminating apoptotic cells and initiating the blood clotting cascade. It is also a precursor of phosphatidylethanolamine, produced by PtdS decarboxylase in bacteria, yeast, and mammalian cells. Furthermore, PtdS acts as a cofactor for several necessary enzymes that participate in signaling pathways. Beyond these functions, several studies indicate that PtdS plays a role in various cerebral functions, including activating membrane signaling pathways, neuroinflammation, neurotransmission, and synaptic refinement associated with the central nervous system (CNS). This review discusses the occurrence of PtdS in nature and biosynthesis via enzymes and genes in plants, yeast, prokaryotes, mammalian cells, and the brain, and enzymatic synthesis through phospholipase D (PLD). Furthermore, we discuss metabolism, its role in the CNS, the fortification of foods, and supplementation for improving some memory functions, the results of which remain unclear. PtdS can be a potentially beneficial addition to foods for kids, seniors, athletes, and others, especially with the rising consumer trend favoring functional foods over conventional pills and capsules. Clinical studies have shown that PtdS is safe and well tolerated by patients.

Targeting auditory verbal hallucinations in schizophrenia: effective connectivity changes induced by low-frequency rTMS

Low-frequency repetitive transcranial magnetic stimulation (rTMS) has emerged as an effective intervention for alleviating symptoms of psychiatric disorders, particularly schizophrenia characterized by persistent auditory verbal hallucinations (AVH). However, the underlying mechanism of its action remain elusive. This study employed a randomized controlled design to investigate the impact of low-frequency rTMS on the neural connectivity at the stimulate site, specifically left temporoparietal junction (TPJ), in schizophrenia patients with suffering from AVH. Using Dynamic Causal Modeling (DCM), this study assessed changes in directed connectivity patterns and their correlations with clinical symptomatology. The results demonstrated significant improvements in AVH. Notably, significant changes in connectivity were observed, including both abnormal functional connectivity and effective connectivity among multiple brain regions. Particularly, the inhibition effects from the left precentral gyrus and left medial superior frontal gyrus to the left TPJ were closely associated with improvements in AVH. These findings underscore the potential of rTMS to effectively modulate neural pathways implicated in hallucinations in schizophrenia, thereby providing a neurobiological foundation for its therapeutic effects.

The causal relationship between immune cell traits and schizophrenia: a Mendelian randomization analysis

INTRODUCTION

The complex and unresolved pathogenesis of schizophrenia has posed significant challenges to its diagnosis and treatment. While recent research has established a clear association between immune function and schizophrenia, the causal relationship between the two remains elusive.

METHODS

We employed a bidirectional two-sample Mendelian randomization approach to investigate the causal relationship between schizophrenia and 731 immune cell traits by utilizing public GWAS data. We further validated the causal relationship between schizophrenia and six types of white cell measures.

RESULTS

We found the overall causal effects of schizophrenia on immune cell traits were significantly higher than the reverse ones (0.011 ± 0.049 vs 0.001 ± 0.016, p < 0.001), implying that disease may lead to an increase in immune cells by itself. We also identified four immune cell traits that may increase the risk of schizophrenia: CD11c+ monocyte %monocyte (odds ratio (OR): 1.06, 95% confidence interval (CI): 1.03~1.09, FDR = 0.027), CD11c+ CD62L- monocyte %monocyte (OR:1.06, 95% CI: 1.03~1.09, FDR = 0.027), CD25 on IgD+ CD38- naive B cell (OR:1.03, 95% CI:1.01~1.06, FDR = 0.042), and CD86 on monocyte (OR = 1.04, 95% CI:1.01~1.06, FDR = 0.042). However, we did not detect any significant causal effects of schizophrenia on immune cell traits. Using the white blood cell traits data, we identified that schizophrenia increases the lymphocyte counts (OR:1.03, 95%CI: 1.01-1.04, FDR = 0.007), total white blood cell counts (OR:1.02, 95%CI: 1.01-1.04, FDR = 0.021) and monocyte counts (OR:1.02, 95%CI: 1.00-1.03, FDR = 0.034). The lymphocyte counts were nominally associated with the risk of schizophrenia (OR:1.08,95%CI:1.01-1.16, P=0.019).

DISCUSSION

Our study found that the causal relationship between schizophrenia and the immune system is complex, enhancing our understanding of the role of immune regulation in the development of this disorder. These findings offer new insights for exploring diagnostic and therapeutic options for schizophrenia.

Identification of Bipolar Disorder and Schizophrenia Based on Brain CT and Deep Learning Methods

With the increasing prevalence of mental illness, accurate clinical diagnosis of mental illness is crucial. Compared with MRI, CT has the advantages of wide application, low price, short scanning time, and high patient cooperation. This study aims to construct a deep learning (DL) model based on CT images to make identification of bipolar disorder (BD) and schizophrenia (SZ). A total of 506 patients (BD = 227, SZ = 279) and 179 healthy controls (HC) was collected from January 2022 to May 2023 at two hospitals, and divided into an internal training set and an internal validation set according to a ratio of 4:1. An additional 65 patients (BD = 35, SZ = 30) and 40 HC were recruited from different hospitals, and served as an external test set. All subjects accepted the conventional brain CT examination. The DenseMD model for identify BD and SZ using multiple instance learning was developed and compared with other classical DL models. The results showed that DenseMD performed excellently with an accuracy of 0.745 in the internal validation set, whereas the accuracy of the ResNet-18, ResNeXt-50, and DenseNet-121model was 0.672, 0.664, and 0.679, respectively. For the external test set, DenseMD again outperformed other models with an accuracy of 0.724; however, the accuracy of the ResNet-18, ResNeXt-50, and DenseNet-121model was 0.657, 0.638, and 0.676, respectively. Therefore, the potential of DL models for identification of BD and SZ based on brain CT images was established, and identification ability of the DenseMD model was better than other classical DL models.

Sex-dependent association study of complement C4 gene with treatment-resistant schizophrenia and hospitalization frequency

The complement component 4 (C4) gene, codes for two isotypes, C4A and C4B, and can exist in long or short forms (C4L and C4S). The C4AL variant has been associated with elevated schizophrenia (SCZ) risk. Here, we investigated the relationship between C4 variation and clinical outcomes in SCZ. N = 434 adults with SCZ or schizoaffective disorder were included in this retrospective study. A three-step genotyping workflow was performed to determine C4 copy number variants. These variants were tested for association with clinical outcome measures, including treatment-resistant SCZ (TRS), number of hospitalizations (NOH), and symptom severity (PANSS). Sex and ancestry stratified analyses were performed. We observed a marginally significant association between C4S and TRS in males only, and a negative association between C4S and NOH in the total sample. C4AS had negative association with NOH in males and non-Europeans. Lastly, C4A copy numbers and C4A predicted brain expression showed negative association with NOH in males only. Our study provides further support for sex-specific effect of C4 on SCZ clinical outcomes, and also suggests that C4S and C4AS might have a protective effect against increased severity. C4 could potentially serve as a genetic biomarker in the future, however, more research is required.

Investigating Cannabidiol's potential as a supplementary treatment for schizophrenia: A narrative review

Schizophrenia presents a complex mental health challenge, often inadequately addressed by existing antipsychotic treatments, leading to persistent symptoms and adverse effects. Hence, developing alternative therapeutic approaches is crucial. Cannabidiol (CBD), a nonpsychoactive compound in Cannabis sativa, has been extensively explored for its therapeutic potential in treating psychiatric disorders, including schizophrenia. CBD exhibits antipsychotic, anxiolytic, and neuroprotective effects. However, distinguishing the individual effects of CBD and THC remains challenging. Therefore, this review aims to critically analyze the potential role of CBD as an adjunctive therapy in schizophrenia treatment. The therapeutic action of CBD may involve activating the 5-hydroxytryptamine 1A receptors and suppressing the G-protein-coupled receptor 55, thereby affecting various neurotransmitter systems. Additionally, the anti-inflammatory and antioxidative effects of CBD may contribute to alleviating neuroinflammation linked to schizophrenia. Compared to typical antipsychotics, CBD demonstrates a lower incidence of side effects and it exhibited favorable tolerability in clinical trials. A 2012 clinical trial demonstrated the efficacy of CBD in reducing both positive and negative symptoms of schizophrenia, presenting a safer profile than that of traditional antipsychotics. However, further research is needed to fully establish the safety and efficacy of CBD as an adjunctive treatment. Future research directions encompass exploring detailed antipsychotic mechanisms, long-term safety profiles, interactions with current antipsychotics, optimal dosing, and patient-specific factors such as genetic predispositions. Despite these research needs, the potential of CBD to enhance the quality of life and symptom management positions it as a promising candidate for innovative schizophrenia treatment approaches.

Neurostructural changes in schizophrenia and treatment-resistance: a narrative review

Schizophrenia is a complex disorder characterized by multiple neurochemical abnormalities and structural changes in the brain. These abnormalities may begin before recognizable clinical symptoms appear and continue as a dynamic process throughout the illness. Recent advances in imaging techniques have significantly enriched our comprehension of these structural alterations, particularly focusing on gray and white matter irregularities and prefrontal, temporal, and cingulate cortex alterations. Some of the changes suggest treatment resistance to antipsychotic medications, while treatment nonadherence and relapses may further exacerbate structural abnormalities. This narrative review aims to discuss the literature about alterations and deficits within the brain, which could improve the understanding of schizophrenia and how to interpret neurostructural changes.