Schizophrenia: an integrated sociodevelopmental-cognitive model

New Drug Treatments for Schizophrenia: A Review of Approaches to Target Circuit Dysfunction

Schizophrenia is a leading cause of global disease burden. Current drug treatments are associated with significant side effects and have limited efficacy for many patients, highlighting the need to develop new approaches that target other aspects of the neurobiology of schizophrenia. Preclinical, in vivo imaging, postmortem, genetic, and pharmacological studies have highlighted the key role of cortical GABAergic (gamma-aminobutyric acidergic)-glutamatergic microcircuits and their projections to subcortical dopaminergic circuits in the pathoetiology of negative, cognitive, and psychotic symptoms. Antipsychotics primarily act downstream of the dopaminergic component of this circuit. However, multiple drugs are currently in development that could target other elements of this circuit to treat schizophrenia. These include drugs for GABAergic or glutamatergic targets, including glycine transporters, D-amino acid oxidase, sodium channels, or potassium channels. Other drugs in development are likely to primarily act on pathways that regulate the dopaminergic system, such as muscarinic or trace amine receptors or 5-HT2A receptors, while PDE10A inhibitors are being developed to modulate the downstream consequences of dopaminergic dysfunction. Our review considers where new drugs may act on this circuit and their latest clinical trial evidence in terms of indication, efficacy, and side effects. Limitations of the circuit model, including whether there are neurobiologically distinct subgroups of patients, and future directions are also considered. Several drugs based on the mechanisms reviewed have promising clinical data, with the muscarinic agonist KarXT most advanced. If these drugs are approved for clinical use, they have the potential to revolutionize understanding of the pathophysiology and treatment of schizophrenia.

Association between childhood trauma and depressive symptoms in adolescents during the post COVID-19 pandemic: the mediating role of social peer rejection

This study aimed to investigate the associations of childhood trauma and its facets with depressive symptoms in depressed adolescents during the post COVID-19 epidemic, and explore the potential mediating role of social peer rejection in these associations. A total of 413 adolescents with depressive disorders completed the Chinese version of the Child Trauma Questionnaire Short Form, the Social Peer Rejection, and the Children's Depression Inventory. Childhood trauma (β = 0.42, p < 0.01) and social peer rejection (β = 0.18, p < 0.01) were positively related to depressive symptoms, after adjustment for demographic factors. Furthermore, social peer rejection partly mediated the relationship between childhood trauma and depressive symptoms, and the mediation effect ratio was 17.0% (p < 0.001). This study found that childhood trauma and social peer rejection are both risk factors for depressive symptoms, and social peer rejection played a mediating role in the relationship between childhood trauma and depressive symptoms.

Schizophrenia spectrum disorders in children and adolescents: Clinical, phenomenological, diagnostic, and prognostic features across subtypes

Schizophrenia spectrum disorders (SSD) typically have a diagnostically recognizable onset in young adulthood, yet it is not unusual that help-seeking due to initial SSD-related clinical manifestations emerge in earlier developmental phases, such as childhood and adolescence. Varieties of SSD manifestations in children and adolescents can be distinguished according to variations in clinical expressivity, severity and timing (i.e. developmental stage). Some individuals may reach the full clinical threshold for a diagnosis of schizophrenia according to the same descriptive diagnostic criteria used for adults, and in this case, it's possible to distinguish a pre-pubertal onset in childhood (aka Very Early Onset Schizophrenia, VEOS) and a post-pubertal onset in adolescence (aka Early Onset Schizophrenia, EOS). Other individuals may not reach such clinically overt diagnostic threshold but nonetheless present Childhood Schizotypal Disorder (CSD) or a Clinical High-Risk for Psychosis (CHRP). While EOS is clinically more similar to the canonical adult-onset presentation, the other 3 subgroups (i.e. VEOS, CSD, CHRP) present more nuances and specific clinical characteristics, which require ad-hoc developmental and phenomenological considerations for appropriate differential diagnosis and prognosis. Therefore, current scoping review intends to saturate such knowledge gap with respect to early SSD-phenotypes.

Joint-trajectories of clinical severity, social functioning and cannabis use in first-episode psychosis: A 5-year longitudinal study in 2 urban early intervention services

Cannabis use is associated with increased psychosis incidence alongside worse outcomes. The role of cannabis may be complex, vary across patients and over time. Yet, few have examined the longer-term trajectories of cannabis use, symptoms and functioning and their inter-relationships. We conducted a 5-year longitudinal study to estimate joint-trajectories of clinical severity, social functioning, and cannabis use via group-based multi-trajectory modelling on a sample of 395 incident FEP cases. Associations of trajectories with socio-demographic and clinical factors were tested using multinomial regression. The best-fitting model identified 5 joint-trajectories. A first group (N = 93,23.7 %) presented only marginal improvement despite not using cannabis, while a second with no cannabis use and a third group with low-decreasing use showed clinical amelioration. Among those with baseline harmful cannabis use, a fourth group progressively discontinued use and improved clinically (N = 78,19.9 %). A fifth group with continued use did not significantly improve over follow-up (N = 74,18.8 %), and also had the highest odds of homelessness (OR = 22.5,95 %CI = 6.25-81.1) and childhood adversities (OR = 2.25,95 %CI = 1.71-2.97). There is substantial heterogeneity in the joint-trajectories of cannabis use and FEP outcomes. Our findings support the need for intervention aimed at cannabis reduction among heavy users. Multi-disciplinary, trauma-informed interventions may benefit those with persistent cannabis use, given its associations with childhood and social adversity.

Gender differences and clinical correlates in the age of the first hospitalization in patients with drug-naïve schizophrenia in China: a cross-sectional study

Gender differences in the onset age of schizophrenia have been reported in many studies, but differences in the age of the first hospitalization and associated factors have not been explored. The present study investigated gender differences and clinical correlates in the age of the first hospitalization in drug-naïve schizophrenia (DNS). A total of 144 DNS patients and 67 health controls were included. Demographic information, duration of untreated psychosis (DUP), Positive and Negative Symptom Scale (PANSS) scores, the Brief Psychiatric Rating Scale (BPRS) scores, Global Assessment of Functioning (GAF) scores, and MATRICS Consensus Cognitive Battery (MCCB) scores were collected and analyzed. The age of the first hospitalization was significantly earlier in males than in females (P < 0.01). In addition, there were significant differences in the age of the first hospitalization in terms of marital status, occupation, family ranking, suicide attempt, and place of residence (all P < 0.05). After Bonferroni correction, only DUP had a positive correlation with the age of the first hospitalization (PBonferroni < 0.05/6 = 0.0083). Multivariate linear regression analysis showed that gender (β = 0.141, t = 2.434, P = 0.016), marital status (β = 0.219, t = 3.463, P = 0.001), family ranking (β = 0.300, t = 4.918, P < 0.001), suicide attempt (β = 0.348, t = 5.549, P < 0.001), and DUP (β = 0.190, t = 2.969, P < 0.004) positively predicted the age of the first hospitalization. The age of the first hospitalization in male DNS was earlier than in females. In addition, gender, marital status, suicide attempt, DUP, and family rank were independent risk factors for the age of the first hospitalization.

Adverse effects associated with antipsychotic use in older adults

INTRODUCTION

Antipsychotic (AP) medications are extensively utilized for diverse psychiatric and non-psychiatric conditions, but they are associated with significant adverse effects in older adults. This expert opinion review provides an updated profile of adverse effects associated with AP medications in older adults.

AREAS COVERED

This review specifically examines real-world evidence for adverse events associated with AP use, including all-cause mortality, falls and fractures, diabetes, cardiovascular and cerebrovascular events, acute kidney injury, venous thromboembolism/pulmonary embolism, extrapyramidal symptoms, and infections based on real-world evidence.

EXPERT OPINION

This comprehensive safety review of AP revealed multiple adverse events in older adults. All-cause mortality, more associated with typical APs than atypicals, underscores a dose-dependent risk, urging cautious prescribing practices and avoidance of typical APs. Falls/fractures associated with atypical APs highlight the importance of judicious dosing and -close monitoring, especially after initiation. Cardiovascular risks, particularly stroke, with AP use emphasize the need for vigilant monitoring. Extrapyramidal symptoms, more linked to typical APs, also pose a significant risk in older adults. Pneumonia and pulmonary embolism/venous thromboembolism demand cautious consideration of APs, prompting the need for additional real-world studies to inform clinical practice. Conflicting evidence on diabetes and acute kidney injury necessitates ongoing studies and further research in older adults.

A Transdiagnostic Network Analysis of Childhood Trauma and Psychopathology

BACKGROUND AND HYPOTHESIS

Psychiatric comorbidities suggest that symptoms overlap across different diagnoses; the transdiagnostic network approach is valuable for studying psychopathology. Childhood trauma is a common transdiagnostic risk factor for psychiatric disorders, but the complex relationship between childhood trauma and psychopathology has seldom been investigated using a large cross-sectional transdiagnostic sample.

STUDY DESIGN

This study recruited 869 patients with different diagnoses, including 418 schizophrenia, 215 bipolar disorder, and 236 major depressive disorder. Participants completed psychiatric interviews and self-report questionnaires. We constructed dimension- and item-level Least Absolute Shrinkage and Selection Operator-based (LASSO) networks to explore the relationship between childhood trauma, psychopathology, and duration of illness. Moreover, we constructed directed acyclic graphs (DAGs) to tentatively clarify the potential directions of associations among these variables. Network Comparison Tests (NCTs) were conducted for different diagnostic groups and gender-stratified groups.

STUDY RESULTS

The transdiagnostic LASSO networks showed that different types of childhood trauma exerted distinct impacts on various psychopathological dimensions. Emotional abuse was linked to depressive symptoms, physical abuse to excited symptoms, sexual abuse to positive and disorganized symptoms, emotional neglect to depressive symptoms and motivation and pleasure (MAP) deficits factor of negative symptoms, and physical neglect to MAP factor. The DAG findings generally concurred with the LASSO network. The NCT showed comparable networks.

CONCLUSIONS

Our findings suggest that childhood trauma is significantly associated with the development of psychopathology across different diagnostic groups. The affective pathway model suggests that early identification and tailored interventions would be needed for people with a history of childhood trauma.

From diagnosis to dialogue - reconsidering the DSM as a conversation piece in mental health care: a hypothesis and theory

The Diagnostic and Statistical Manual of Mental Disorders, abbreviated as the DSM, is one of mental health care's most commonly used classification systems. While the DSM has been successful in establishing a shared language for researching and communicating about mental distress, it has its limitations as an empirical compass. In the transformation of mental health care towards a system that is centered around shared decision-making, person-centered care, and personal recovery, the DSM is problematic as it promotes the disengagement of people with mental distress and is primarily a tool developed for professionals to communicate about patients instead of with patients. However, the mental health care system is set up in such a way that we cannot do without the DSM for the time being. In this paper, we aimed to describe the position and role the DSM may have in a mental health care system that is evolving from a medical paradigm to a more self-contained profession in which there is increased accommodation of other perspectives. First, our analysis highlights the DSM's potential as a boundary object in clinical practice, that could support a shared language between patients and professionals. Using the DSM as a conversation piece, a language accommodating diverse perspectives can be co-created. Second, we delve into why people with lived experience should be involved in co-designing spectra of distress. We propose an iterative design and test approach for designing DSM spectra of distress in co-creation with people with lived experience to prevent the development of 'average solutions' for 'ordinary people'. We conclude that transforming mental health care by reconsidering the DSM as a boundary object and conversation piece between activity systems could be a step in the right direction, shifting the power balance towards shared ownership in a participation era that fosters dialogue instead of diagnosis.

Modelling the longitudinal dynamics of paranoia in psychosis: A temporal network analysis over 20 years

BACKGROUND

Paranoia is a key feature of psychosis that can be highly debilitating. Theories of paranoia mostly interface with short-scale or cross-sectional data models, leaving the longitudinal course of paranoia underspecified.

METHODS

We develop an empirical characterisation of two aspects of paranoia - persecutory and referential delusions - in individuals with psychosis over 20 years. We examine delusional dynamics by applying a Graphical Vector Autoregression Model to data collected from the Chicago Follow-up Study (n = 135 with a range of psychosis-spectrum diagnoses). We adjusted for age, sex, IQ, and antipsychotic use.

RESULTS

We found that referential and persecutory delusions are central themes, supported by other primary delusions, and are strongly autoregressive - the presence of referential and persecutory delusions is predictive of their future occurrence. In a second analysis we demonstrate that social factors influence the severity of referential, but not persecutory, delusions.

IMPLICATIONS

We suggest that persecutory delusions represent central, resistant states in the cognitive landscape, whereas referential beliefs are more flexible, offering an important window of opportunity for intervention. Our data models can be collated with prior biological, computational, and social work to contribute toward a more complete theory of paranoia and provide more time-dependent evidence for optimal treatment targets.

Neurocognitive function and delusion severity in schizophrenia spectrum disorders

The role of basic neurocognitive function in delusions is unclear despite the association to difficulties in reasoning and decision-making. We investigated 812 individuals with schizophrenia spectrum disorders (SSD) using a broad neuropsychological test battery encompassing motor and mental processing speed, working memory, learning and memory, and executive function. Premorbid and current intellectual function was assessed with NART and WASI. Delusion level and other clinical symptoms were measured with the PANSS and GAF. Hierarchical and k-means cluster analysis using standardized scores showed the presence of two separate clusters where the group with the higher delusion level (n = 291) was characterized by more severe neurocognitive deficits (>1.5 standard deviations below the healthy control mean), higher PANSS scores, lower GAF scores, and lower intelligence levels compared to the cluster with mild impairments (n = 521). We conclude that a higher delusion level is related to neurocognitive deficits across domains. Further, the validity of the two separate clusters was indicated by significant differences in clinical symptoms, everyday function, and intellectual ability. Compared to those with mild delusion levels, SSD patients with higher delusion levels seem particularly disadvantaged, with co-occurring general symptoms and lower daily function, underscoring the need for clinical and psychosocial support programs. A limitation of this study is the cross sectional design. Longitudinal studies are needed to determine the causal relationship between delusions and neurocognitive function.

Short-term antipsychotic treatment reduces functional connectivity of the striatum in first-episode drug-naïve early-onset schizophrenia

BACKGROUND

The striatum is thought to play a critical role in the pathophysiology and antipsychotic treatment of schizophrenia. Previous studies have revealed abnormal functional connectivity (FC) of the striatum in early-onset schizophrenia (EOS) patients. However, no prior studies have examined post-treatment changes of striatal FC in EOS patients.

METHODS

We recruited 49 first-episode drug-naïve EOS patients to have resting-state functional magnetic resonance imaging scans at baseline and after 8 weeks of treatment with antipsychotics, along with baseline scanning of 34 healthy controls (HCs) for comparison purposes. We examined the FC values between each seed in striatal subregion and the rest of the brain. The Positive and Negative Syndrome Scale (PANSS) was applied to measure psychiatric symptoms in patients.

RESULTS

Compared with HCs at baseline, EOS patients exhibited weaker FC of striatal subregions with several brain regions of the salience network and default mode network. Meanwhile, FC between the dorsal caudal putamen (DCP) and left supplementary motor area, as well as between the DCP and right postcentral gyrus, was negatively correlated with PANSS negative scores. Furthermore, after 8 weeks of treatment, EOS patients showed decreased FC between subregions of the putamen and the triangular part of inferior frontal gyrus, middle frontal gyrus, supramarginal gyrus and inferior parietal lobule.

CONCLUSIONS

Decreased striatal FC is evident, even in the early stages of schizophrenia, and enhance our understanding of the neurodevelopmental abnormalities in schizophrenia. The findings also demonstrate that reduced striatal FC occurs after antipsychotic therapy, indicating that antipsychotic effects need to be accounted for when considering striatal FC abnormalities in schizophrenia.

The impact of sex on gene expression in the brain of schizophrenic patients: a systematic review and meta-analysis of transcriptomic studies

BACKGROUND

Schizophrenia is a severe neuropsychiatric disorder characterized by altered perception, mood, and behavior that profoundly impacts patients and society despite its relatively low prevalence. Sex-based differences have been described in schizophrenia epidemiology, symptomatology and outcomes. Different studies explored the impact of schizophrenia in the brain transcriptome, however we lack a consensus transcriptomic profile that considers sex and differentiates specific cerebral regions.

METHODS

We performed a systematic review on bulk RNA-sequencing studies of post-mortem brain samples. Then, we fulfilled differential expression analysis on each study and summarized their results with regions-specific meta-analyses (prefrontal cortex and hippocampus) and a global all-studies meta-analysis. Finally, we used the consensus transcriptomic profiles to functionally characterize the impact of schizophrenia in males and females by protein-protein interaction networks, enriched biological processes and dysregulated transcription factors.

RESULTS

We discovered the sex-based dysregulation of 265 genes in the prefrontal cortex, 1.414 genes in the hippocampus and 66 genes in the all-studies meta-analyses. The functional characterization of these gene sets unveiled increased processes related to immune response functions in the prefrontal cortex in male and the hippocampus in female schizophrenia patients and the overexpression of genes related to neurotransmission and synapses in the prefrontal cortex of female schizophrenia patients. Considering a meta-analysis of all brain regions available, we encountered the relative overexpression of genes related to synaptic plasticity and transmission in females and the overexpression of genes involved in organizing genetic information and protein folding in male schizophrenia patients. The protein-protein interaction networks and transcription factors activity analyses supported these sex-based profiles.

CONCLUSIONS

Our results report multiple sex-based transcriptomic alterations in specific brain regions of schizophrenia patients, which provides new insight into the role of sex in schizophrenia. Moreover, we unveil a partial overlapping of inflammatory processes in the prefrontal cortex of males and the hippocampus of females.

Childhood Adversity and Incident Psychotic Experiences in Early Adulthood: Cognitive and Psychopathological Mediators

BACKGROUND AND HYPOTHESIS

Childhood adversity is often described as a potential cause of incident psychotic experiences, but the underlying mechanisms are not well understood. We aimed to examine the mediating role of cognitive and psychopathological factors in the relation between childhood adversity and incident psychotic experiences in early adulthood.

STUDY DESIGN

We analyzed data from the Avon Longitudinal Study of Parents and Children, a large population-based cohort study. Childhood adversity was measured prospectively from birth to age 11 years, mediators (anxiety, depression, external locus of control [LoC], negative symptoms) were assessed at approximately 16 years of age, and incident psychotic experiences were assessed at ages 18 and 24 years. Mediation was examined via the counterfactual g-computation formula.

STUDY RESULTS

In total, 7% of participants had incident suspected or definite psychotic experiences in early adulthood. Childhood adversity was related to more incident psychotic experiences (ORadjusted = 1.34, 95% CI = 1.21; 1.49), and this association was partially mediated via all mediators examined (proportion mediated: 19.9%). In separate analyses for each mediator, anxiety, depression, external LoC, and negative symptoms were all found to mediate the link between adversity and incident psychotic experiences. Accounting for potential confounders did not modify our results.

CONCLUSIONS

Our study shows that cognitive biases as well as mood symptomatology may be on the causal pathway between early-life adversity and the development of psychotic experiences. Future studies should determine which mediating factors are most easily modifiable and most likely to reduce the risk of developing psychotic experiences.

What Remains to Be Discovered in Schizophrenia Therapeutics: Contributions by Advancing the Molecular Mechanisms of Drugs for Psychosis and Schizophrenia

Schizophrenia is a frequently debilitating and complex mental disorder affecting approximately 1% of the global population, characterized by symptoms such as hallucinations, delusions, disorganized thoughts and behaviors, cognitive dysfunction, and negative symptoms. Traditional treatment has centered on postsynaptic dopamine antagonists, commonly known as antipsychotic drugs, which aim to alleviate symptoms and improve functioning and the quality of life. Despite the availability of these medications, significant challenges remain in schizophrenia therapeutics, including incomplete symptom relief, treatment resistance, and medication side effects. This opinion article explores advancements in schizophrenia treatment, emphasizing molecular mechanisms, novel drug targets, and innovative delivery methods. One promising approach is novel strategies that target neural networks and circuits rather than single neurotransmitters, acknowledging the complexity of brain region interconnections involved in schizophrenia. Another promising approach is the development of biased agonists, which selectively activate specific signaling pathways downstream of receptors, offering potential for more precise pharmacological interventions with fewer side effects. The concept of molecular polypharmacy, where a single drug targets multiple molecular pathways, is exemplified by KarXT, a novel drug combining xanomeline and trospium to address both psychosis and cognitive dysfunction. This approach represents a comprehensive strategy for schizophrenia treatment, potentially improving outcomes for patients. In conclusion, advancing the molecular understanding of schizophrenia and exploring innovative therapeutic strategies hold promise for addressing the unmet needs in schizophrenia treatment, aiming for more effective and tailored interventions. Future research should focus on these novel approaches to achieve better clinical outcomes and improve the functional level and quality of life for individuals with schizophrenia.

Electrophysiological Markers Predicting Antipsychotic Treatment Response in Patients with Schizophrenia: A Retrospective Study

Purpose

This study aimed to provide an objective means of predicting treatment responses in patients with schizophrenia using quantitative electroencephalography (qEEG) as an electrophysiological indicator. We obtained qEEG recordings from patients with schizophrenia and explored them for patterns indicative of treatment responsiveness.

Patients and Methods

The study included 68 patients had been diagnosed with schizophrenia spectrum disorder. After retrospectively gathering demographic information, clinical data such as qEEG, Positive and Negative Syndrome Scale (PANSS), a multiple regression analysis was performed. This analysis employed baseline qEEG findings as independent variables and PANSS score changes as dependent variables to discern causal relationships.

Results

The mean age of the participants was 38.4 years(SD =13.73). The mean PANSS score on admission was 92.97, decreasing to 67.41 at discharge. Multiple regression analysis revealed that delta waves in T4 (β=0.346, t=3.165, p=0.002), and high-beta waves in Fp2 (β=0.231, t=2.361, p=0.021) were associated with PANSS changes in absolute power. In addition, the delta waves of O2 (β=0.250, t=3.288, p=0.002); beta waves of T3 (β=-1.463, t=-5.423, p<0.001) and O2 (β=0.551, t=3.366, p=0.001); high beta waves of Fp1 (β=0.307, t=4.026, p<0.001), T3 (β=0.855, t=4.414, p<0.001) and T6 (β=-0.838, t=-4.559, p<0.001) of absolute power using the Z-score were also related to PANSS changes. Pearson's correlation analysis showed that only delta waves at Cz (r= 0.246, p=0.043) in absolute power correlated with changes in the PANSS.

Conclusion

We found that certain qEEG wave patterns in patients with schizophrenia prior to antipsychotic treatment were linked to PANSS changes before and after treatment. Delta waves and beta waves, primarily in the frontal and temporal regions, were found to be significantly associated with changes in PANSS scores. In the future, the qEEG indicators identified in this study could serve as electrophysiological markers for predicting antipsychotic treatment responses in patients with schizophrenia.

Associations of Cognitive Expectancies With Auditory Hallucinations and Hallucinatory-Like Experiences in Patients With Schizophrenia

BACKGROUND

Various neurocognitive models explore perceptual distortions and hallucinations in schizophrenia and the general population. A variant of predictive coding account suggests that strong priors, like cognitive expectancy, may influence perception. This study examines if stronger cognitive expectancies result in more auditory false percepts in clinical and healthy control groups, investigates group differences, and explores the association between false percepts and hallucinations.

STUDY DESIGN

Patients diagnosed with schizophrenia with current auditory hallucinations (n = 51) and without hallucinations (n = 66) and healthy controls (n = 51) underwent the False Perception Task under various expectancy conditions. All groups were examined for the presence and severity of hallucinations or hallucinatory-like experiences.

STUDY RESULTS

We observed a main effect of condition across all groups, ie, the stronger the cognitive expectancy, the greater the ratio of auditory false percepts. However, there was no group effect for the ratio of auditory false percepts. Despite modest pairwise correlations in the hallucinating group, the ratio of auditory false percepts was not predicted by levels of hallucinations and hallucinatory-like experiences in a linear mixed model.

CONCLUSIONS

The current study demonstrates that strong priors in the form of cognitive expectancies affect perception and play a role in perceptual disturbances. There is also a tentative possibility that overreliance on strong priors may be associated with hallucinations in currently hallucinating subjects. Possible, avoidable confounding factors are discussed in detail.

The role of psychotic-like experiences in the association between aberrant salience and anxiety: A psychopathological proposal based on a case-control study

AIM

Aberrant salience (AS) and psychotic-like experiences (PLEs) have been proven to be linked. Moreover, anxiety is a key symptom in psychosis-prone subjects and most psychotic patients. We propose a model that attempts to interpret the role of PLEs in the association between AS and anxiety among healthy controls and psychotic patients.

METHODS

Demographic and psychometric data (Aberrant Salience Inventory, Community Assessment of Psychic Experiences, Symptom Check List-90-revised) from 163 controls and 44 psychotic patients was collected. Descriptive statistics, correlations, a linear regression model and a mediation analysis with covariates were subsequently performed.

RESULTS

AS correlated with more frequent positive PLEs and higher anxiety levels in both patients and controls. However, positive PLEs' frequency mediated the relationship between AS and anxiety only among controls.

CONCLUSIONS

PLEs linked to AS appear to induce anxiety among the control group but not among psychotic patients. The progressive loss of both novelty and insight, which may, respectively, impair the somatic emotional reactivity to PLEs and the ability to recognize some bodily phenomena as the embodied correlates of anxiety, is seen as the most probable theoretical explanation.

The circadian system: A neglected player in neurodevelopmental disorders

Patients with neurodevelopmental disorders, such as autism spectrum disorder, often display abnormal circadian rhythms. The role of the circadian system in these disorders has gained considerable attention over the last decades. Yet, it remains largely unknown how these disruptions occur and to what extent they contribute to the disorders' development. In this review, we examine circadian system dysregulation as observed in patients and animal models of neurodevelopmental disorders. Second, we explore whether circadian rhythm disruptions constitute a risk factor for neurodevelopmental disorders from studies in humans and model organisms. Lastly, we focus on the impact of psychiatric medications on circadian rhythms and the potential benefits of chronotherapy. The literature reveals that patients with neurodevelopmental disorders display altered sleep-wake cycles and melatonin rhythms/levels in a heterogeneous manner, and model organisms used to study these disorders appear to support that circadian dysfunction may be an inherent characteristic of neurodevelopmental disorders. Furthermore, the pre-clinical and clinical evidence indicates that circadian disruption at the environmental and genetic levels may contribute to the behavioural changes observed in these disorders. Finally, studies suggest that psychiatric medications, particularly those prescribed for attention-deficit/hyperactivity disorder and schizophrenia, can have direct effects on the circadian system and that chronotherapy may be leveraged to offset some of these side effects. This review highlights that circadian system dysfunction is likely a core pathological feature of neurodevelopmental disorders and that further research is required to elucidate this relationship.

Risk and protective factors for recovery at 3-year follow-up after first-episode psychosis onset: a multivariate outcome approach

PURPOSE

Recovery in people with first-episode psychosis (FEP) remains a major issue. When risk factors are studied in relation to the disorder, potential protective factors should also be considered since they can modulate this relationship. This study is aimed at exploring which premorbid and baseline characteristics are associated with a good and poor global recovery in patients with FEP at 3-year follow-up.

METHODS

We categorized patients' outcome by using a Latent Class Analysis (LCA) considering a multimodal set of symptomatic and functional outcomes. A Mixed effects Models Repeated Measures analysis of variance (MMRM) was used to highlight group differences over time on symptomatic and functional outcomes assessed during the 3-year follow-up.

RESULTS

A total of 325 patients with FEP aged between 18 and 35 years were included. Two groups were identified. A total of 187 patients (57.5%) did not achieve recovery, and 138 patients (42.5%) achieved recovery. Recovered patients had generally a better premorbid and baseline profile in comparison with non-recovered patients (as among which shorter duration of untreated psychosis (DUP), higher degree of insight, better functional level and lower illness severity at baseline). The trajectories for the psychopathological and functional outcomes over 36 months differed between the non-recovered and the recovered group of patients.

CONCLUSIONS

Our results pointed to some variables associated with recovery, acting as potential protective factors. These should be considered for early intervention programs to promote psychological resilience specifically in those with a worse prognosis in order to mitigate the effects of the variables that make them more vulnerable to poorer outcome.

Grief as a Risk Factor for Psychosis: A Systematic Review

PURPOSE OF REVIEW

The assessment of the risk of triggering psychosis upon exposure to grief is a challenge in clinical practice. Adequate diagnosis and early prevention are essential and may be helpful in the evolution of normal grief. We aimed to identify studies exploring grief as a risk factor for developing psychosis.

RECENT FINDINGS

A systematic review of 3 databases (PubMed, EMBASE, and Cochrane Library) was conducted.

RESULTS

In the first approach 618 studies were identified. After the selection process, 15 studies were included in the review. The association between grief and the risk of developing psychosis occurred at younger ages (before 18 years of age) in a first-degree relative and as a consequence of suicide or accidental death. We found that risk factors such as comorbidity, mental problems, unemployment, economic difficulties, and close ties with the deceased have a negative impact on health causing greater vulnerability to psychosis with a risk of developing complicated grief, with statistically significant results regarding the associations between early parental death and the probability of developing psychosis in adulthood.

A Comprehensive Review of Schizophrenia and Antipsychotic Metabolism as a Predictor of Treatment Response

Some patients with schizophrenia fail to respond to standard antipsychotics and are considered treatment-resistant. In these cases, clozapine is the only antipsychotic with proven efficacy, but its use is complicated by severe adverse effects, complex monitoring requirements, and non-response. Variation within the CYP450 enzymes CYP1A2, CYP2D6, CYP3A4, and CYP2C19 has been linked to the differential metabolism of antipsychotics. Testing for CYP450 single nucleotide polymorphisms may be a useful predictor of treatment resistance and could inform pharmacogenetic recommendations to identify potential treatment non-responders. Nonetheless, it remains uncertain whether differential antipsychotic metabolism is directly related to treatment efficacy. This comprehensive narrative review endeavours to delve into the molecular and genetic basis of schizophrenia, and discuss the current treatments available. In particular, we aim to examine the aetiology of treatment resistance in schizophrenia through available literature and discuss current challenges within the field.

Reduction in presynaptic dopamine transporter may be associated with future problematic delusion

OBJECTIVES

Psychosis, especially in delusions, greatly impairs the quality of life of patients with Parkinson's disease (PD) and their caregivers. Few objective risk indicators of the association between psychosis and clinical features has been reported. It is unclear whether the reduction in DAT binding represents the underlying mechanism of delusion or its association. There are no long-term data on the objective prognostic value of DAT binding for delusions. We investigated whether DAT binding at baseline can be a prognostic risk factor for future development of PD delusions.

MATERIALS AND METHODS

We reviewed the detailed clinical chart of patients with PD without a history of psychosis who underwent [123I]FP-CIT SPECT during the disease. The endpoint was defined as when the delusions occurred during the 5 years after the examination of [123I]FP-CIT SPECT. Specific binding ratio (SBR) values were calculated.

RESULTS

Sixty-one patients with PD were included in the analysis, and 11 patients had delusions within 5 years of [123I] FP-CIT SPECT. The average (p = 0.004), minimum (p = 0.004), maximum (p = 0.001), right-sided (p = 0.002), and left-sided (p = 0.003) SBRs in the striatum were significantly smaller in patients with delusions than in patients without delusions. Each difference of each SBR was significantly smaller than those without delusions after adjusting after controlling for age, gender, disease severity, timing of [123I]FP-CIT SPECT, anti-parkinsonian medications, hospitalization, administering more or newly anti-parkinsonian drugs, and receiving DBS or LCIG.

CONCLUSIONS

PD delusions is still problematic, and lowering DAT binding may be helpful for predicting future delusions, regardless of the timing of [123I]FP-CIT SPECT.

Loneliness and psychotic-like experiences in middle-aged and older adults: the mediating role of selective attention to threat and external attribution biases

OBJECTIVES

Loneliness has been associated with psychotic-like experiences (PLEs) in the general population, but the mechanisms underlying this association are poorly understood. Theoretical models, corroborated by empirical findings, signify the key role of biased cognition in both loneliness and psychosis. This study tested whether two cognitive biases - Selective Attention to Threat (ATB) and External Attribution Bias (EAB) - account for the association between loneliness and PLEs.

METHOD

A convenience sample (n = 357) of middle-aged and older adults (aged 40+) was recruited online from the UK population. The parallel mediation model with two the aforementioned cognitive biases as mediators was tested.

RESULTS

A mediation effect between loneliness and PLEs via ATB (ab1 = 0.441, 95% CI = [0.264, 0.646]) and EAB (ab2 = 0.354, 95% CI [0.124, 0.627] was established. This model remained significant after controlling for the current symptoms of anxiety and depression.

CONCLUSION

Greater loneliness was associated with a higher rate of PLEs in the sample of middle-aged and older adults. This association was fully explained by ATB and EAB, independent of the current symptoms of anxiety and depression.

Identification of differentially expressed genes of blood leukocytes for Schizophrenia

Background

Schizophrenia (SCZ) is a severe neurodevelopmental disorder with brain dysfunction. This study aimed to use bioinformatic analysis to identify candidate blood biomarkers for SCZ.

Methods

The study collected peripheral blood leukocyte samples of 9 SCZ patients and 20 healthy controls for RNA sequencing analysis. Bioinformatic analyses included differentially expressed genes (DEGs) analysis, pathway enrichment analysis, and weighted gene co-expression network analysis (WGCNA).

Results

This study identified 1,205 statistically significant DEGs, of which 623 genes were upregulated and 582 genes were downregulated. Functional enrichment analysis showed that DEGs were mainly enriched in cell chemotaxis, cell surface, and serine peptidase activity, as well as involved in Natural killer cell-mediated cytotoxicity. WGCNA identified 16 gene co-expression modules, and five modules were significantly correlated with SCZ (p < 0.05). There were 106 upregulated genes and 90 downregulated genes in the five modules. The top ten genes sorted by the Degree algorithm were RPS28, BRD4, FUS, PABPC1, PCBP1, PCBP2, RPL27A, RPS21, RAG1, and RPL27. RAG1 and the other nine genes belonged to the turquoise and pink module respectively. Pathway enrichment analysis indicated that these 10 genes were mainly involved in processes such as Ribosome, cytoplasmic translation, RNA binding, and protein binding.

Conclusion

This study finds that the gene functions in key modules and related enrichment pathways may help to elucidate the molecular pathogenesis of SCZ, and the potential of key genes to become blood biomarkers for SCZ warrants further validation.

Task-based default mode network connectivity predicts cognitive impairment and negative symptoms in first-episode schizophrenia

Individuals diagnosed with schizophrenia (SZ) demonstrate difficulty distinguishing between internally and externally generated stimuli. These aberrations in "source monitoring" have been theorized as contributing to symptoms of the disorder, including hallucinations and delusions. Altered connectivity within the default mode network (DMN) of the brain has been proposed as a mechanism through which discrimination between self-generated and externally generated events is disrupted. Source monitoring abnormalities in SZ have additionally been linked to impairments in selective attention and inhibitory processing, which are reliably observed via the N100 component of the event-related brain potential elicited during an auditory paired-stimulus paradigm. Given overlapping constructs associated with DMN connectivity and N100 in SZ, the present investigation evaluated relationships between these measures of disorder-related dysfunction and sought to clarify the nature of task-based DMN function in SZ. DMN connectivity and N100 measures were assessed using EEG recorded from SZ during their first episode of illness (N = 52) and demographically matched healthy comparison participants (N = 25). SZ demonstrated less evoked theta-band connectivity within DMN following presentation of pairs of identical auditory stimuli than HC. Greater DMN connectivity among SZ was associated with better performance on measures of sustained attention (p = .03) and working memory (p = .09), as well as lower severity of negative symptoms, though it was not predictive of N100 measures. Together, present findings provide EEG evidence of lower task-based connectivity among first-episode SZ, reflecting disruptions of DMN functions that support cognitive processes. Attentional processes captured by N100 appear to be supported by different neural mechanisms.

TAAR1 agonist ulotaront modulates striatal and hippocampal glutamate function in a state-dependent manner

Aberrant dopaminergic and glutamatergic function, particularly within the striatum and hippocampus, has repeatedly been associated with the pathophysiology of schizophrenia. Supported by preclinical and recent clinical data, trace amine-associated receptor 1 (TAAR1) agonism has emerged as a potential new treatment approach for schizophrenia. While current evidence implicates TAAR1-mediated regulation of dopaminergic tone as the primary circuit mechanism, little is known about the effects of TAAR1 agonists on the glutamatergic system and excitation-inhibition balance. Here we assessed the impact of ulotaront (SEP-363856), a TAAR1 agonist in Phase III clinical development for schizophrenia, on glutamate function in the mouse striatum and hippocampus. Ulotaront reduced spontaneous glutamatergic synaptic transmission and neuronal firing in striatal and hippocampal brain slices, respectively. Interestingly, ulotaront potentiated electrically-evoked excitatory synaptic transmission in both brain regions, suggesting the ability to modulate glutamatergic signaling in a state-dependent manner. Similar striatal effects were also observed with the TAAR1 agonist, RO5166017. Furthermore, we show that ulotaront regulates excitation-inhibition balance in the striatum by specifically modulating glutamatergic, but not GABAergic, spontaneous synaptic events. These findings expand the mechanistic circuit hypothesis of ulotaront and TAAR1 agonists, which may be uniquely positioned to normalize both the excessive dopaminergic tone and regulate abnormal glutamatergic function associated with schizophrenia.

A systematic chart review of pharmacological interventions in patients with clozapine-induced hypersalivation

OBJECTIVES

To investigate the efficacy and tolerability of medications, such as mouthwash use of 1 % atropine sulfate and tropicamide drops, oral amitriptyline and amisulpride used for clozapine-induced hypersalivation (CIH).

METHODS

The medical charts of inpatients with psychotic disorders between 2010 and 2022 were reviewed retrospectively. We detected 161 patients with eligible data who received or commenced clozapine. Primary outcome was defined as the percentage change in the diameter of a wet patch on the pillow (DWP) for improvements in CIH.

RESULTS

The frequency of CIH was 42 % (n = 68). The first step medications for CIH were tropicamide drops (49 %), atropine drops (43 %) and amitriptyline (3 %). After the first step, the median DWP significantly decreased by -33 %. During the index hospitalization, in 18 patients with persistent CIH, the median DWP significantly decreased by -42 % with the second step medications which also included amisulpride. There were no reported serious adverse events. The change in DWP was significantly correlated with the duration of clozapine treatment (r = 306) and clozapine serum level at discharge (r = 0.294). A linear regression model showed a link between the change in DWP and reduced Positive and Negative Syndrome Scale scores.

CONCLUSIONS

Our findings emphasize that mouthwash use of atropine or tropicamide drops has a satisfying and tolerable effect in treating CIH. Switching medications for CIH seems to be effective when CIH persists despite a first step agent. Controlled follow-up studies are needed to understand the relationship between CIH, clozapine serum levels, illness severity, and functioning.

Chronic social stressors and striatal dopamine functioning in humans: A systematic review of SPECT and PET studies

The dopamine hypothesis of schizophrenia posits that elevated striatal dopamine functioning underlies the development of psychotic symptoms. Chronic exposure to social stressors increases psychosis risk, possibly by upregulating striatal dopamine functioning. Here we systematically review single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies that examined the relationship between chronic social stress exposure and in vivo striatal dopamine functioning in humans. We searched the scientific databases PubMed and PsycINFO from inception to August 2023. The quality of the included studies was evaluated with the ten-item Observational Study Quality Evaluation (PROSPERO: CRD42022308883). Twenty-eight studies were included, which measured different aspects of striatal dopamine functioning including dopamine synthesis capacity (DSC), vesicular monoamine transporter type 2 binding, dopamine release following a pharmacological or behavioral challenge, D2/3 receptor binding, and dopamine transporter binding. We observed preliminary evidence of an association between childhood trauma and increased striatal DSC and dopamine release. However, exposure to low socioeconomic status, stressful life events, or other social stressors was not consistently associated with altered striatal dopamine functioning. The quality of available studies was generally low. In conclusion, there is insufficient evidence that chronic social stressors upregulate striatal dopamine functioning in humans. We propose avenues for future research, in particular to improve the measurement of chronic social stressors and the methodological quality of study designs.

Emerging effects of temperature on human cognition, affect, and behaviour

Human body core temperature is tightly regulated within approximately 37 °C. Global near surface temperature has increased by over 1.2 °C between 1850 and 2020. In light of the challenge this poses to human thermoregulation, the present perspective article sought to provide an overview on the effects of varying ambient and body temperature on cognitive, affective, and behavioural domains of functioning. To this end, an overview of observational and experimental studies in healthy individuals and individuals with mental disorders was provided. Within body core temperature at approximately 37 °C, relatively lower ambient and skin temperatures appear to evoke a need for social connection, whereas comparably higher temperatures appear to facilitate notions of other as closer and more sociable. Above-average ambient temperatures are associated with increased conflicts as well as incident psychotic and depressive symptoms, mental disorders, and suicide. With mild hypo- and hyperthermia, paradoxical effects are observed: whereas the acute states are generally characterised by impairments in cognitive performance, anxiety, and irritability, individuals with depression experience longer-term symptom improvements with treatments deliberately inducing these states for brief amounts of time. When taken together, it has thus become clear that temperature is inexorably associated with human cognition, affect, and (potentially) behaviour. Given the projected increase in global warming, further research into the affective and behavioural sequelae of heat and the mechanisms translating it into mental health outcomes is urgently warranted.

Characterizing cognitive subtypes in schizophrenia using cortical curvature

Cognitive deficits are a core symptom of schizophrenia, but research on their neural underpinnings has been challenged by the heterogeneity in deficits' severity among patients. Here, we address this issue by combining logistic regression and random forest to classify two neuropsychological profiles of patients with high (HighCog) and low (LowCog) cognitive performance in two independent samples. We based our analysis on the cortical features grey matter volume (VOL), cortical thickness (CT), and mean curvature (MC) of N = 57 patients (discovery sample) and validated the classification in an independent sample (N = 52). We investigated which cortical feature would yield the best classification results and expected that the 10 most important features would include frontal and temporal brain regions. The model based on MC had the best performance with area under the curve (AUC) values of 76% and 73%, and identified fronto-temporal and occipital brain regions as the most important features for the classification. Moreover, subsequent comparison analyses could reveal significant differences in MC of single brain regions between the two cognitive profiles. The present study suggests MC as a promising neuroanatomical parameter for characterizing schizophrenia cognitive subtypes.

Parvalbumin interneuron deficits in schizophrenia

Parvalbumin-expressing (PV+) interneurons represent one of the most abundant subclasses of cortical interneurons. Owing to their specific electrophysiological and synaptic properties, PV+ interneurons are essential for gating and pacing the activity of excitatory neurons. In particular, PV+ interneurons are critically involved in generating and maintaining cortical rhythms in the gamma frequency, which are essential for complex cognitive functions. Deficits in PV+ interneurons have been frequently reported in postmortem studies of schizophrenia patients, and alterations in gamma oscillations are a prominent electrophysiological feature of the disease. Here, I summarise the main features of PV+ interneurons and review clinical and preclinical studies linking the developmental dysfunction of cortical PV+ interneurons with the pathophysiology of schizophrenia.

The insula: Leveraging cellular and systems-level research to better understand its roles in health and schizophrenia

Schizophrenia is a highly heterogeneous disorder characterized by a multitude of complex and seemingly non-overlapping symptoms. The insular cortex has gained increasing attention in neuroscience and psychiatry due to its involvement in a diverse range of fundamental human experiences and behaviors. This review article provides an overview of the insula's cellular and anatomical organization, functional and structural connectivity, and functional significance. Focusing on specific insula subregions and using knowledge gained from humans and preclinical studies of insular tracings in non-human primates, we review the literature and discuss the functional roles of each subregion, including in somatosensation, interoception, salience processing, emotional processing, and social cognition. Building from this foundation, we then extend these findings to discuss reported abnormalities of these functions in individuals with schizophrenia, implicating insular involvement in schizophrenia pathology. This review underscores the insula's vast role in the human experience and how abnormal insula structure and function could result in the wide-ranging symptoms observed in schizophrenia.

Dopamine signaling enriched striatal gene set predicts striatal dopamine synthesis and physiological activity in vivo

The polygenic architecture of schizophrenia implicates several molecular pathways involved in synaptic function. However, it is unclear how polygenic risk funnels through these pathways to translate into syndromic illness. Using tensor decomposition, we analyze gene co-expression in the caudate nucleus, hippocampus, and dorsolateral prefrontal cortex of post-mortem brain samples from 358 individuals. We identify a set of genes predominantly expressed in the caudate nucleus and associated with both clinical state and genetic risk for schizophrenia that shows dopaminergic selectivity. A higher polygenic risk score for schizophrenia parsed by this set of genes predicts greater dopamine synthesis in the striatum and greater striatal activation during reward anticipation. These results translate dopamine-linked genetic risk variation into in vivo neurochemical and hemodynamic phenotypes in the striatum that have long been implicated in the pathophysiology of schizophrenia.

NMDA receptor modulation by Esculetin: Investigating behavioral, biochemical and neurochemical effects in schizophrenic mice model

Schizophrenia, a global mental health disorder affecting approximately 1 % of the population, is characterized by neurotransmitter dysregulation, particularly dopamine, serotonin, and glutamate. Current antipsychotic therapies, despite their efficacy, are accompanied by adverse effects, which has motivated researchers to investigate more secure substitutes. This study examines the potential antipsychotic effects of esculetin, a natural coumarin derivative recognized for its wide-ranging pharmacological activities (anti-inflammatory, antioxidant, anti-pathogenic, anticancer, and neuroprotective), in animal model of schizophrenia induced by ketamine. In order to induce disease, acute and chronic ketamine administration was performed on Swiss albino mice, supplemented with esculetin (as the test substance) and clozapine (as the reference standard). Behavioral studies and biochemical assays were performed to evaluate positive, negative, and cognitive symptoms of schizophrenia, as well as antioxidant and oxidant levels in various brain regions. Esculetin demonstrated significant improvements in behavioral symptoms, attenuated oxidative stress and neuroinflammation, and modulated neurotransmitter levels. Afterwards, ELISA was performed to evaluate levels of schizophrenia biomarkers AChE, BDNF. Moreover, proinflammatory cytokines (IL-6 and TNF-α) and NF-κB were also determined. Histopathological parameters of under study brain parts i.e., hippocampus, cortex and striata were also assessed. Esculetin and clozapine significantly (***p < 0.0001) altered ketamine induced behavioral symptoms and attenuated ketamine induced oxidative stress and neuroinflammation. Additionally, esculetin significantly (***p < 0.0001) altered neurotransmitter (dopamine, serotonin, glutamate) levels. ELISA analysis depicts ketamine reduced BDNF levels in hippocampus, cortex and striata while esculetin significantly (***p < 0.0001) increased BDNF levels in under study three parts of brain. Histopathological changes were seen in test groups. The findings of this study indicate that esculetin may have therapeutic potential in the treatment of schizophrenia induced by ketamine. As a result, esculetin may have the potential to be utilized as a treatment for schizophrenia.

Longitudinal MicroRNA Signature of Conversion to Psychosis

BACKGROUND AND HYPOTHESIS

The emergence of psychosis in ultra-high-risk subjects (UHR) is influenced by gene-environment interactions that rely on epigenetic mechanisms such as microRNAs. However, whether they can be relevant pathophysiological biomarkers of psychosis' onset remains unknown.

STUDY DESIGN

We present a longitudinal study of microRNA expression, measured in plasma by high-throughput sequencing at baseline and follow-up, in a prospective cohort of 81 UHR, 35 of whom developed psychosis at follow-up (converters). We combined supervised machine learning and differential graph analysis to assess the relative weighted contribution of each microRNA variation to the difference in outcome and identify outcome-specific networks. We then applied univariate models to the resulting microRNA variations common to both strategies, to interpret them as a function of demographic and clinical covariates.

STUDY RESULTS

We identified 207 microRNA variations that significantly contributed to the classification. The differential network analysis found 276 network-specific correlations of microRNA variations. The combination of both strategies identified 25 microRNAs, whose gene targets were overrepresented in cognition and schizophrenia genome-wide association studies findings. Interpretable univariate models further supported the relevance of miR-150-5p and miR-3191-5p variations in psychosis onset, independent of age, sex, cannabis use, and medication.

CONCLUSIONS

In this first longitudinal study of microRNA variation during conversion to psychosis, we combined 2 methodologically independent data-driven strategies to identify a dynamic epigenetic signature of the emergence of psychosis that is pathophysiologically relevant.

Gene-environment pathways to cognitive intelligence and psychotic-like experiences in children

In children, psychotic-like experiences (PLEs) are related to risk of psychosis, schizophrenia, and other mental disorders. Maladaptive cognitive functioning, influenced by genetic and environmental factors, is hypothesized to mediate the relationship between these factors and childhood PLEs. Using large-scale longitudinal data, we tested the relationships of genetic and environmental factors (such as familial and neighborhood environment) with cognitive intelligence and their relationships with current and future PLEs in children. We leveraged large-scale multimodal data of 6,602 children from the Adolescent Brain and Cognitive Development Study. Linear mixed model and a novel structural equation modeling (SEM) method that allows estimation of both components and factors were used to estimate the joint effects of cognitive phenotypes polygenic scores (PGSs), familial and neighborhood socioeconomic status (SES), and supportive environment on NIH Toolbox cognitive intelligence and PLEs. We adjusted for ethnicity (genetically defined), schizophrenia PGS, and additionally unobserved confounders (using computational confound modeling). Our findings indicate that lower cognitive intelligence and higher PLEs are significantly associated with lower PGSs for cognitive phenotypes, lower familial SES, lower neighborhood SES, and less supportive environments. Specifically, cognitive intelligence mediates the effects of these factors on PLEs, with supportive parenting and positive school environments showing the strongest impact on reducing PLEs. This study underscores the influence of genetic and environmental factors on PLEs through their effects on cognitive intelligence. Our findings have policy implications in that improving school and family environments and promoting local economic development may enhance cognitive and mental health in children.

A systematic review of performance-based assessment studies on cognitive biases in schizophrenia spectrum psychoses and clinical high-risk states: A summary of 40 years of research

Cognitive models of psychosis have stimulated empirical studies on cognitive biases involved in schizophrenia spectrum psychoses and their symptoms. This systematic review aimed to summarize the studies on the role of cognitive biases as assessed in different performance-based tasks in schizophrenia spectrum psychoses and clinical high-risk states. We focused on five cognitive biases linked to psychosis, i.e., aberrant salience, attentional biases, source monitoring biases, jumping to conclusions, and bias against disconfirmatory evidence. We identified N = 324 studies published in N = 308 articles fulfilling inclusion criteria. Most studies have been cross-sectional and confirmed that the schizophrenia spectrum psychoses are related to exaggerated cognitive biases compared to healthy controls. On the contrary, less evidence suggests a higher tendency for cognitive biases in the UHR sample. The only exceptions were source monitoring and jumping to conclusions, which were confirmed to be exaggerated in both clinical groups. Hallucinations and delusions were the most frequent symptoms studied in the context of cognitive biases. Based on the findings, we presented a hypothetical model on the role of interactions between cognitive biases or additive effects of biases in shaping the risk of psychosis. Future research is warranted for further development of cognitive models for psychosis.

The effectiveness and tolerability of trauma-focused psychotherapies for psychotic symptoms: A systematic review of trauma-focused psychotherapies

INTRODUCTION

Psychological trauma is an established risk factor for psychosis. Trauma-focused psychotherapies (TFPT) have been suggested as a potential treatment for reducing psychotic symptoms in those who have experienced trauma. We therefore sought to investigate the effectiveness, tolerability, and acceptability of TFPT for psychotic symptoms.

METHODS

We conducted a systematic review of studies of any form of TFPT that measured psychotic symptoms across a broad range of diagnoses.

RESULTS

From 2584 papers initially identified, 17 studies (857 participants) met eligibility criteria. TFPT were found to be well tolerated, with very few adverse events. Acceptability was also high, with a mean dropout rate of 20%.

CONCLUSIONS

Whilst the evidence of effectiveness for TFPT in reducing psychotic symptoms is weak, we found tentative evidence in favour of exposure-based interventions. Methodologically rigorous trials investigating the efficacy of TFPT for the treatment of psychotic symptoms are needed to assess this promising intervention.

Gamma Oscillations and Potassium Channel Modulation in Schizophrenia: Targeting GABAergic Dysfunction

Impairments in gamma-aminobutyric acid (GABAergic) interneuron function lead to gamma power abnormalities and are thought to underlie symptoms in people with schizophrenia. Voltage-gated potassium 3.1 (Kv3.1) and 3.2 (Kv3.2) channels on GABAergic interneurons are critical to the generation of gamma oscillations suggesting that targeting Kv3.1/3.2 could augment GABAergic function and modulate gamma oscillation generation. Here, we studied the effect of a novel potassium Kv3.1/3.2 channel modulator, AUT00206, on resting state frontal gamma power in people with schizophrenia. We found a significant positive correlation between frontal resting gamma (35-45 Hz) power (n = 22, r = 0.613, P < .002) and positive and negative syndrome scale (PANSS) positive symptom severity. We also found a significant reduction in frontal gamma power (t13 = 3.635, P = .003) from baseline in patients who received AUT00206. This provides initial evidence that the Kv3.1/3.2 potassium channel modulator, AUT00206, may address gamma oscillation abnormalities in schizophrenia.

Effect of DIO2 Gene Polymorphism on Thyroid Hormone Levels and Its Correlation with the Severity of Schizophrenia in a Pakistani Population

Low levels of triiodothyronine (T3) in the brain lead to increased dopamine receptor sensitivity, potentially resulting in schizophrenia. Iodothyronine deiodinase 2 (DIO2) is the only enzyme which converts tetraiodothyronine (T4) to T3 in the brain. DIO2 polymorphism of rs225014 results in the expression of non-functioning DIO2. Therefore, this study aimed to investigate the association of rs255014 with schizophrenia and its impact on thyroid hormone levels. This study included 150 schizophrenia cases and 150 controls. DNA was extracted from blood and subjected to PCR and amplicon sequencing. Serum thyroid profiles were determined using chemiluminescent magnetic microparticle immunoassay. Statistical analyses involved independent sample t-tests, Chi-square, and Pearson's correlation tests. The results revealed a higher frequency of the reference genotype (TT) in controls compared to cases (p < 0.05). However, rs225014 did not influence serum thyroid levels or the severity of schizophrenia (p > 0.05). Interestingly, control subjects exhibited significantly higher T3 levels (p < 0.001) than cases. Regardless of the genotype (TT or CC), the control group had higher mean T3 levels than the corresponding case group (p < 0.05). In conclusion, rs225014 is associated with schizophrenia and has no effect on serum thyroid hormone levels.

The schizophrenia syndrome, circa 2024: What we know and how that informs its nature

With new data about different aspects of schizophrenia being continually generated, it becomes necessary to periodically revisit exactly what we know. Along with a need to review what we currently know about schizophrenia, there is an equal imperative to evaluate the construct itself. With these objectives, we undertook an iterative, multi-phase process involving fifty international experts in the field, with each step building on learnings from the prior one. This review assembles currently established findings about schizophrenia (construct, etiology, pathophysiology, clinical expression, treatment) and posits what they reveal about its nature. Schizophrenia is a heritable, complex, multi-dimensional syndrome with varying degrees of psychotic, negative, cognitive, mood, and motor manifestations. The illness exhibits a remitting and relapsing course, with varying degrees of recovery among affected individuals with most experiencing significant social and functional impairment. Genetic risk factors likely include thousands of common genetic variants that each have a small impact on an individual's risk and a plethora of rare gene variants that have a larger individual impact on risk. Their biological effects are concentrated in the brain and many of the same variants also increase the risk of other psychiatric disorders such as bipolar disorder, autism, and other neurodevelopmental conditions. Environmental risk factors include but are not limited to urban residence in childhood, migration, older paternal age at birth, cannabis use, childhood trauma, antenatal maternal infection, and perinatal hypoxia. Structural, functional, and neurochemical brain alterations implicate multiple regions and functional circuits. Dopamine D-2 receptor antagonists and partial agonists improve psychotic symptoms and reduce risk of relapse. Certain psychological and psychosocial interventions are beneficial. Early intervention can reduce treatment delay and improve outcomes. Schizophrenia is increasingly considered to be a heterogeneous syndrome and not a singular disease entity. There is no necessary or sufficient etiology, pathology, set of clinical features, or treatment that fully circumscribes this syndrome. A single, common pathophysiological pathway appears unlikely. The boundaries of schizophrenia remain fuzzy, suggesting the absence of a categorical fit and need to reconceptualize it as a broader, multi-dimensional and/or spectrum construct.

Impaired emotional awareness is associated with childhood maltreatment exposure and positive symptoms in schizophrenia

Objectives

Evidence suggests that emotional awareness-the ability to identify and label emotions-may be impaired in schizophrenia and related to positive symptom severity. Exposure to childhood maltreatment is a risk factor for both low emotional awareness and positive symptoms.

Methods

The current investigation examines associations between a performance-based measure of emotional awareness, positive symptom severity, and childhood maltreatment exposure in 44 individuals with a schizophrenia-spectrum disorder and 48 healthy comparison participants using the electronic Levels of Emotional Awareness Scale (eLEAS), Positive and Negative Syndrome Scale (PANSS) and Childhood Trauma Questionnaire (CTQ).

Results

Patients demonstrated significant deficits in emotional awareness overall, which was true for both self and others. In patients, lower emotional awareness was significantly associated with more severe positive symptoms. Emotional awareness was significantly impaired in patients with schizophrenia with self-reported maltreatment exposure, relative to other groups. Severity of maltreatment was not significantly associated with emotional awareness or positive symptoms when looking continuously, and there was no significant indirect effect.

Conclusion

These data suggest that emotional awareness impairments observed in schizophrenia may be exacerbated by exposure to childhood maltreatment, possibly putting individuals at greater risk for experiencing positive symptoms of psychosis.

Stress, Environment and Early Psychosis

Existing literature provides extended evidence of the close relationship between stress dysregulation, environmental insults, and psychosis onset. Early stress can sensitize genetically vulnerable individuals to future stress, modifying their risk for developing psychotic phenomena. Neurobiological substrate of the aberrant stress response to hypothalamic-pituitary-adrenal axis dysregulation, disrupted inflammation processes, oxidative stress increase, gut dysbiosis, and altered brain signaling, provides mechanistic links between environmental risk factors and the development of psychotic symptoms. Early-life and later-life exposures may act directly, accumulatively, and repeatedly during critical neurodevelopmental time windows. Environmental hazards, such as pre- and perinatal complications, traumatic experiences, psychosocial stressors, and cannabis use might negatively intervene with brain developmental trajectories and disturb the balance of important stress systems, which act together with recent life events to push the individual over the threshold for the manifestation of psychosis. The current review presents the dynamic and complex relationship between stress, environment, and psychosis onset, attempting to provide an insight into potentially modifiable factors, enhancing resilience and possibly influencing individual psychosis liability.

Pediatric traumatic brain injury as a risk factor for psychosis and psychotic symptoms: a systematic review and meta-analysis

BACKGROUND

Psychosis is one of the most disabling psychiatric disorders. Pediatric traumatic brain injury (pTBI) has been cited as a developmental risk factor for psychosis, however this association has never been assessed meta-analytically.

METHODS

A systematic review and meta-analysis of the association between pTBI and subsequent psychotic disorders/symptoms was performed. The study was pre-registered (CRD42022360772) adopting a random-effects model to estimate meta-analytic odds ratio (OR) and 95% confidence interval (CI) using the Paule-Mandel estimator. Subgroup (study location, study design, psychotic disorder v. subthreshold symptoms, assessment type, and adult v. adolescent onset) and meta-regression (quality of evidence) analyses were also performed. The robustness of findings was assessed through sensitivity analyses. The meta-analysis is available online as a computational notebook with an open dataset.

RESULTS

We identified 10 relevant studies and eight were included in the meta-analysis. Based on a pooled sample size of 479686, the pooled OR for the association between pTBI and psychosis outcomes was 1.80 (95% CI 1.11-2.95). There were no subgroup effects and no outliers. Both psychotic disorder and subthreshold symptoms were associated with pTBI. The overall association remained robust after removal of low-quality studies, however the OR reduced to 1.43 (95% CI 1.04-1.98). A leave-one-out sensitivity analysis showed the association was robust to removal of all but one study which changed the estimate to marginally non-significant.

CONCLUSIONS

We report cautious meta-analytic evidence for a positive association between pTBI and future psychosis. New evidence will be key in determining long-term reliability of this finding.

Biomarkers for Psychosis: Are We There Yet? Umbrella Review of 1478 Biomarkers

Background and Hypothesis

This umbrella review aims to comprehensively synthesize the evidence of association between peripheral, electrophysiological, neuroimaging, neuropathological, and other biomarkers and diagnosis of psychotic disorders.

Study Design

We selected systematic reviews and meta-analyses of observational studies on diagnostic biomarkers for psychotic disorders, published until February 1, 2018. Data extraction was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Evidence of association between biomarkers and psychotic disorders was classified as convincing, highly suggestive, suggestive, weak, or non-significant, using a standardized classification. Quality analyses used the Assessment of Multiple Systematic Reviews (AMSTAR) tool.

Study Results

The umbrella review included 110 meta-analyses or systematic reviews corresponding to 3892 individual studies, 1478 biomarkers, and 392 210 participants. No factor showed a convincing level of evidence. Highly suggestive evidence was observed for transglutaminase autoantibodies levels (odds ratio [OR] = 7.32; 95% CI: 3.36, 15.94), mismatch negativity in auditory event-related potentials (standardized mean difference [SMD] = 0.73; 95% CI: 0.5, 0.96), P300 component latency (SMD = -0.6; 95% CI: -0.83, -0.38), ventricle-brain ratio (SMD = 0.61; 95% CI: 0.5, 0.71), and minor physical anomalies (SMD = 0.99; 95% CI: 0.64, 1.34). Suggestive evidence was observed for folate, malondialdehyde, brain-derived neurotrophic factor, homocysteine, P50 sensory gating (P50 S2/S1 ratio), frontal N-acetyl-aspartate, and high-frequency heart rate variability. Among the remaining biomarkers, weak evidence was found for 626 and a non-significant association for 833 factors.

Conclusions

While several biomarkers present highly suggestive or suggestive evidence of association with psychotic disorders, methodological biases, and underpowered studies call for future higher-quality research.

Schizophrenia: from neurochemistry to circuits, symptoms and treatments

Schizophrenia is a leading cause of global disability. Current pharmacotherapy for the disease predominantly uses one mechanism - dopamine D2 receptor blockade - but often shows limited efficacy and poor tolerability. These limitations highlight the need to better understand the aetiology of the disease to aid the development of alternative therapeutic approaches. Here, we review the latest meta-analyses and other findings on the neurobiology of prodromal, first-episode and chronic schizophrenia, and the link to psychotic symptoms, focusing on imaging evidence from people with the disorder. This evidence demonstrates regionally specific neurotransmitter alterations, including higher glutamate and dopamine measures in the basal ganglia, and lower glutamate, dopamine and γ-aminobutyric acid (GABA) levels in cortical regions, particularly the frontal cortex, relative to healthy individuals. We consider how dysfunction in cortico-thalamo-striatal-midbrain circuits might alter brain information processing to underlie psychotic symptoms. Finally, we discuss the implications of these findings for developing new, mechanistically based treatments and precision medicine for psychotic symptoms, as well as negative and cognitive symptoms.

The Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

Sexual abuse and psychotic phenomena: a directed acyclic graph analysis of affective symptoms using English national psychiatric survey data

BACKGROUND

Sexual abuse and bullying are associated with poor mental health in adulthood. We previously established a clear relationship between bullying and symptoms of psychosis. Similarly, we would expect sexual abuse to be linked to the emergence of psychotic symptoms, through effects on negative affect.

METHOD

We analysed English data from the Adult Psychiatric Morbidity Surveys, carried out in 2007 (N = 5954) and 2014 (N = 5946), based on representative national samples living in private households. We used probabilistic graphical models represented by directed acyclic graphs (DAGs). We obtained measures of persecutory ideation and auditory hallucinosis from the Psychosis Screening Questionnaire, and identified affective symptoms using the Clinical Interview Schedule. We included cannabis consumption and sex as they may determine the relationship between symptoms. We constrained incoming edges to sexual abuse and bullying to respect temporality.

RESULTS

In the DAG analyses, contrary to our expectations, paranoia appeared early in the cascade of relationships, close to the abuse variables, and generally lying upstream of affective symptoms. Paranoia was consistently directly antecedent to hallucinations, but also indirectly so, via non-psychotic symptoms. Hallucinosis was also the endpoint of pathways involving non-psychotic symptoms.

CONCLUSIONS

Via worry, sexual abuse and bullying appear to drive a range of affective symptoms, and in some people, these may encourage the emergence of hallucinations. The link between adverse experiences and paranoia is much more direct. These findings have implications for managing distressing outcomes. In particular, worry may be a salient target for intervention in psychosis.

The Challenge of Managing Refractory Psychosis Amid Multiple Medication Side Effects: A Case Report and Review of the Literature

Antipsychotics are the mainstay for the treatment of schizophrenia and other psychotic disorders; however, these agents are associated with an extensive side effect profile that may complicate treatment outcomes. We present the case of a 35-year-old woman with a history of schizoaffective disorder and five prior psychiatric hospitalizations. The patient first presented to the hospital for disorganized behavior, in addition to poor sleep, auditory hallucinations, and racing thoughts in the context of medication nonadherence. She received two loading doses of intra-muscular paliperidone with fair symptomatic improvement. After discharge, she was scheduled to receive a monthly dose of paliperidone, which she missed, resulting in decompensation, re-emergence of psychosis, and another hospitalization two months later. She was given the missed dose with no improvement and progressive deterioration, for which alternative agents were tried. She received olanzapine and was tried briefly on quetiapine and haloperidol as well, with no benefit, and she also developed abnormal perioral movements. She was reloaded with paliperidone, and her psychotic symptoms improved, although she developed akathisia and hyperprolactinemia. The patient returned to the hospital two days later after being discharged, due to disorganized behavior and multiple delusions. Clozapine was started and titrated to 100 mg qam and 200 mg qhs. While on clozapine, she developed profuse sialorrhea that was treated with sublingual atropine drops, and by the time of discharge psychotic symptoms had markedly improved, perioral movements diminished, and prolactin level trended down. The patient maintained stability for over a year after the last admission. Identifying antipsychotics to successfully treat refractory psychosis and managing their multiple potential side effects is challenging but can result in better quality of life for patients as well as improved treatment adherence. This case report is unique in the way it illustrates this point, while discussing different approaches to managing multiple side effects that can happen simultaneously.

Basal-Forebrain Cholinergic Nuclei Alterations are Associated With Medication and Cognitive Deficits Across the Schizophrenia Spectrum

BACKGROUND AND HYPOTHESIS

The cholinergic system is altered in schizophrenia. Particularly, patients' volumes of basal-forebrain cholinergic nuclei (BFCN) are lower and correlated with attentional deficits. It is unclear, however, if and how BFCN changes and their link to cognitive symptoms extend across the schizophrenia spectrum, including individuals with at-risk mental state for psychosis (ARMS) or during first psychotic episode (FEP).

STUDY DESIGN

To address this question, we assessed voxel-based morphometry (VBM) of structural magnetic resonance imaging data of anterior and posterior BFCN subclusters as well as symptom ratings, including cognitive, positive, and negative symptoms, in a large multi-site dataset (n = 4) comprising 68 ARMS subjects, 98 FEP patients (27 unmedicated and 71 medicated), 140 patients with established schizophrenia (SCZ; medicated), and 169 healthy controls.

RESULTS

In SCZ, we found lower VBM measures for the anterior BFCN, which were associated with the anticholinergic burden of medication and correlated with patients' cognitive deficits. In contrast, we found larger VBM measures for the posterior BFCN in FEP, which were driven by unmedicated patients and correlated at-trend with cognitive deficits. We found no BFCN changes in ARMS. Altered VBM measures were not correlated with positive or negative symptoms.

CONCLUSIONS

Results demonstrate complex (posterior vs. anterior BFCN) and non-linear (larger vs. lower VBM) differences in BFCN across the schizophrenia spectrum, which are specifically associated both with medication, including its anticholinergic burden, and cognitive symptoms. Data suggest an altered trajectory of BFCN integrity in schizophrenia, influenced by medication and relevant for cognitive symptoms.