Exploring causal mechanisms of psychosis risk

Potential risk factors for methamphetamine use among inmates in a Japanese prison

BACKGROUND

In Japan, drug addiction recovery guidance and social reintegration programs are implemented for eligible inmates in many prisons. However, methamphetamine addiction, especially among those with a history of thinner inhalation, often seems not to be adequately addressed in addiction treatment programs. The comorbidities of substance use disorders may be generally overlooked. This study aimed to provide valuable data for guiding the development of programs to combat drug addiction and support social reintegration for inmates. The first step of this study sought to determine the association between history of daily/regular methamphetamine use and use of other substances as well as the relationship between methamphetamine use and sociodemographic background.

METHODS

This retrospective study included 470 consecutive inmates whose data were obtained and who consulted a certified psychiatrist. Chi-square tests and paired t-tests were used for the analysis. Furthermore, a multinominal regression analysis was performed.

RESULTS

Our findings revealed that the history of daily/regular methamphetamine use was significantly associated with the history of psychiatric consultation, sexually transmitted infections, daily/regular thinner inhalation, and daily/regularly tobacco smoking. Moreover, daily/regular thinner inhalation was initiated at a significantly younger age than methamphetamine use. In addition, tobacco smoking was initiated at a significantly younger age than methamphetamine use.

CONCLUSION

The present study suggested that a history of daily/regular thinner inhalation and daily/regular tobacco smoking may serve as potential risk factors for the development of daily/regular methamphetamine use. Furthermore, these findings highlight the significant association between thinner or nicotine addiction and subsequent methamphetamine addiction. These results may provide valuable insights for supporting and protecting inmates with methamphetamine addiction as well as individuals at risk.

TRIAL REGISTRATION

Not applicable.

Characterizing the Social Epigenome in Mexican Patients with Early-Onset Psychosis

Background: Psychosis is one of the leading causes of disability worldwide. Individuals with early-onset psychosis (EOP) tend to experience a worse prognosis and shorter life expectancy. The etiology of EOP remains unclear, but epigenetic mechanisms are known to serve as the interface between environmental exposures and biological processes to better understand its etiology. Objectives: We characterized the sociodemographic and clinical characteristics, as well as genome-wide epigenetic markers, in Mexican patients with EOP. Methods: We estimated epigenetic age, performed an epigenome-wide association study, and finally developed an epigenetic risk score (MRS) to predict manifestations of psychosis. Results: We found that patients with EOP have a higher epigenetic age using Wu's clock (p = 0.015). Moreover, accelerated epigenetic age was correlated with chronological age (PedBE clock, p = 0.046), global functioning (Wu's clock, p = 0.027), and psychiatric admissions (DNAmTL, p = 0.038). In addition, we observed that a reduction in years of schooling is associated with an increase on epigenetic age (Levine's clock, β = 5.07, p = 0.001). In our epigenome-wide association study, we identified eight CpGs associated with EOP. Noteworthy, a psychosis-methylation risk score (EOP-MRS) was associated with panic disorder (β = 1.36, p = 0.03), as well as auditory (β = 1.28, p = 0.04) and visual (β = 1.22, p = 0.04) hallucinations. Conclusions: Years of education have an impact on epigenetic age. Additionally, our study suggests associations of DNA methylation with EOP. Finally, we developed an MRS that associates clinical manifestations of psychosis.

PSYSCAN multi-centre study: baseline characteristics and clinical outcomes of the clinical high risk for psychosis sample

Predicting outcomes in individuals at clinical high risk (CHR) of developing psychosis remains challenging using clinical metrics alone. The PSYSCAN project aimed to enhance predictive value by integrating data across clinical, environmental, neuroimaging, cognitive, and peripheral blood biomarkers. PSYSCAN employed a naturalistic, prospective design across 12 sites (Europe, Australia, Asia, Americas). Assessments were conducted at baseline, 3, 6, and 12 months, with follow-ups at 18 and 24 months to evaluate clinical and functional outcomes. The study included 238 CHR individuals and 134 healthy controls (HC). At baseline, CHR and HC groups differed significantly in age, education, IQ, and vocational and relationship status. Cannabis and tobacco use did not significantly differ between groups, however CHR individuals had higher proportion of moderate to high risk of tobacco abuse. A substantial portion of the CHR sample met DSM criteria for anxiety (53.4%) and/or mood disorders (52.9%), with some prescribed antidepressants (38.7%), antipsychotics (13.9%), or benzodiazepines (16.4%). Over the follow-up period, 25 CHR individuals (10.5%) transitioned to psychosis. However, the CHR group as a whole showed improvements in functioning and attenuated psychotic symptoms. Similar to other recent multi-centre studies, the CHR cohort exhibits high comorbidity rates and relatively low psychosis transition rates. These findings highlight the clinical heterogeneity within CHR populations and suggest that outcomes extend beyond psychosis onset, reinforcing the need for broader prognostic models that consider functional and transdiagnostic outcomes.

Evaluating the Exposome Score for Schizophrenia in a Transdiagnostic Psychosis Cohort: Associations With Psychosis Risk, Symptom Severity, and Personality Traits

BACKGROUND

Investigations of causal pathways for psychosis can be guided by the identification of environmental risk factors. A recently developed composite risk tool, the exposome score for schizophrenia (ES-SCZ), which controls for intercorrelations between risk factors, has shown fair to good performance. We tested the transdiagnostic psychosis classifier performance of the ES-SCZ with the Bipolar-Schizophrenia Network for Intermedial Phenotypes data and examined its relationship with clinical-level outcomes.

STUDY DESIGN

We computed the case-control classifier performance for the ES-SCZ from cross-sectional data on 1055 volunteers with psychotic diagnoses (schizophrenia, schizoaffective, bipolar psychosis) and 510 controls. Multivariate regression models were used to control for the correlations between outcomes and to correct for the effects of age, sex, and family socioeconomic status across outcomes. We estimated association for the ES-SCZ with psychosis and mood symptom severity, the 5-factor model of personality, and function across biologically defined biotypes, traditional diagnostic categories, and controls.

STUDY RESULTS

ES-SCZ classifier performance for psychosis was fair to good. ES-SCZ associations with personality factor scores were qualitatively similar between psychosis groups and controls with decreased conscientiousness and agreeableness and increased neuroticism. The patterns of associations between ES-SCZ and symptoms differed across biotypes and diagnoses. Biotype 3 and bipolar disorder had consistent within-group associations where greater exposome score predicted more severe symptoms and worse function.

CONCLUSIONS

ES-SCZ performance was consistent with previous reports in this transdiagnostic psychosis sample (adjusted odds ratio: 3.331 [2.834, 3.915], P < .001; area under the curve: 0.762 [0.735, 0.789]). Individual differences in ES-SCZ magnitude may be useful for investigating causal pathways between developmentally relevant exposures and symptomatic expression of psychosis.

Clinical and functional outcomes at 7-year follow-up of children presenting putative antecedents of schizophrenia at age 9-12 years

Identification of youth presenting early risk factors for psychosis may facilitate preventive intervention. Through school-based screening, we recruited 112 children aged 9-12 years who presented multiple putative antecedents of schizophrenia (ASz), a family history of schizophrenia (FHx), or neither of these risk factors (typically-developing; TD). Clinical and functional outcomes were assessed at age 17-21 years (N = 93). Compared to the TD group, the ASz group had higher total Prodromal Questionnaire (PQ) scores (β = 10.59, 95% CI = 3.76, 17.42) and total psychopathology scores (β = 6.13, 95% CI: 1.03, 11.23), were more likely to score above-threshold on the PQ positive symptoms scale (OR = 4.00, 95% CI = 1.08, 14.83), and had lower scores on the Social and Occupational Functioning Scale (β = -9.43, 95% CI = -15.08, -3.77) at follow-up. The FHx and TD groups did not differ on any outcome. Findings suggest that population screening for putative antecedents of schizophrenia may identify children who would benefit from preventative intervention.

Exploring the relationship between frequent cannabis use, belief updating under uncertainty and psychotic-like symptoms

Background

Cannabis users present an important group for investigating putative mechanisms underlying psychosis, as cannabis-use is associated with an increased risk of psychosis. Recent work suggests that alterations in belief-updating under uncertainty underlie psychosis. We therefore compared belief updating under uncertainty between cannabis and non-cannabis users.

Methods

49 regular cannabis users and 52 controls completed the Space Game, via an online platform used for behavioral testing. In the task, participants were asked to predict the location of the stimulus based on previous information, under different uncertainty conditions. Mixed effects models were used to identify significant predictors of mean score, confidence, performance error and learning rate.

Results

Both groups showed decreased confidence in high noise conditions, and increased belief updating in more volatile conditions, suggesting that they could infer the degree and sources of uncertainty. There were no significant effects of group on any of the performance indices. However, within the cannabis group, frequent users showed worse performance than less frequent users.

Conclusion

Belief updating under uncertainty is not affected by cannabis use status but could be impaired in those who use cannabis more frequently. This finding could show a similarity between frequent cannabis use and psychosis risk, as predictors for abnormal belief-updating.