Schizophrenia Research最新文献

Not applicable as this is part of Letters to the Editor.

Background: This study examined the functional and clinical effects of extending Early Intervention Service (EIS) for individuals with first-episode psychosis (FEP) by one additional year, compared with transitioning to standard care (SC) after completing two years of EIS. Age and duration of untreated psychosis (DUP) were explored as potential moderators across a broad age range (15-55 years).

Methods: Secondary analyses were conducted on two randomised controlled trials involving 400 FEP patients who had completed two years of EIS (extended EIS: n = 202; SC: n = 198). Participants were assessed at two years and again at three years. Multiple linear regression and mixed-effects models were used to evaluate treatment effects and the moderating roles of age (<25 vs ≥25 years) and DUP (<92 vs. ≥92 days).

Results: Extended EIS improved functioning relative to SC, including higher employment rates (p = 0.024), increased Role Functioning Scale (RFS) total and subdomain scores (p < 0.001 to 0.015), and better Social and Occupational Functioning Assessment Scale (SOFAS) scores (p < 0.001). Short DUP was associated with greater gains in certain RFS subdomains (p = 0.003 to 0.008) and SOFAS (p < 0.001). Younger patients showed greater improvements in RFS independent living and self-care (p = 0.019), and reductions in overall symptom severity (p = 0.014) and general psychopathology (p = 0.020).

Conclusions: A one-year extension of EIS produced additional functional benefits, with stronger effects observed among younger patients and those with shorter DUP. Extending EIS for individuals who continue to demonstrate functional or clinical difficulties after the initial two-year programme may help optimise long-term recovery and guide efficient service planning.

Toxoplasma gondii (T. gondii), a parasite that can be transmitted to humans by cats, has been proposed as a modifiable risk factor for schizophrenia and related disorders. However, much of the research examining this relationship has relied on cat ownership as a proxy measure for T. gondii exposure. This study examined the relationship between serum T. gondii levels and later psychotic experiences (PEs) and brain volume. We also explored the relationship between cat ownership and T. gondii serology. Using the Avon Longitudinal Study of Parents and Children (ALSPAC), we studied 3542 individuals for whom data on serum T. gondii during childhood and PEs at age 18 were available. Voxel-based morphometry assessed whether MRI measures of grey matter volume at age 20 were associated with T. gondii levels among a subset of the participants (N = 334). Serum T. gondii was not associated with PE group in adjusted models (suspected PEs risk ratio (RR) = 1.06, 95% confidence interval (CI) [0.89-1.27]; definite PEs RR = 0.86, 95% CI [0.65-1.13]; psychotic disorder RR = 1.00, 95% CI [0.73-1.38]). Exposure to cats during gestation was associated with higher T. gondii in adolescence (β = 0.08, p = 0.033), while exposure to cats during childhood was not (β = 0.05, p = 0.310). T. gondii was not associated with grey matter volume in the neuroimaging sample (pFWEs ≥ 0.882, Zs ≤ 3.86). Future work examining the relationship between T. gondii and schizophrenia-spectrum disorders should focus on serology or cat ownership during gestation as a proxy measure of T. gondii exposure, as there was no association between childhood cat ownership and T. gondii.

Substance use is frequently implicated in psychosis. However, the prognostic assumptions guiding differential treatment decisions between substance-induced and primary/affective psychoses have received inconsistent support. Substance-induced psychosis research has often been limited by aggregating substances or using diagnosis as both a grouping variable and an outcome (i.e., diagnostic conversion). The current study examined medical records for 1379 patients for 5 years following their first presentation with psychosis after January 2013 to a regional medical center. Clinically relevant outcomes were compared across groups defined by the substances detected in patients' urine at their initial presentation. Initial drug screen results predicted the initial encounter duration, the likelihood of a future presentation with psychosis and a negative drug screen, and the total hospital days associated with psychosis over 5 years, but not patients' number of psychiatric hospitalizations. Cocaine alone and cannabis combined with stimulants exhibited the courses expected of substance-induced psychosis, including quick remission, infrequent recurrence with negative drug screens, and low healthcare utilization. Amphetamines and cannabis alone exhibited improved prognoses compared to those with negative initial screens, but more chronic courses than expected of substance-induced psychosis. Depressants exhibited similar courses to those with negative initial screens. Other polysubstance combinations displayed divergent outcomes. The chronicity of psychosis associated with certain substances suggests further examination of their course with protracted abstinence, response to psychosis-focused treatments, and the potentially diverse mechanisms by which use precipitates psychosis. Additionally, the dissimilar courses observed for distinct polysubstance combinations emphasize the importance of disambiguating these groups in future research.

Background: Persistence of positive symptoms despite adequate antipsychotic treatment is a clinically challenging situation in schizophrenia. Impaired cortical plasticity is hypothesized to underlie the antipsychotic resistance in schizophrenia. This study evaluated High-Definition-tDCS (HD-tDCS) driven motor cortical plasticity using short-interval cortical inhibition (SICI) paired-pulse protocol in schizophrenia.

Methods: Fifty-three individuals with antipsychotic-resistant schizophrenia (ARS) and 31 healthy subjects underwent transcranial magnetic stimulation-electromyography (TMS-EMG) evaluation before and after (10, 20, 30, and 40 min) of a single session of cathodal HD-tDCS (2 mA; 20 min) over the left M1 area. Cortical plasticity was determined as a change in SICI & SI1_mV (Motor Evoked Potential at 1 mV). The effect of time and group was assessed using linear mixed-effects models.

Results: A group*time interaction (t = 2.23) was noted in SICI at 40th minute after cathodal HD-tDCS, revealing that patients with ARS had significantly poorer and ill-sustained motor cortical excitatory changes following cathodal HD-tDCS compared to healthy controls. Furthermore, clozapine-resistant, ie, Ultra Resistant Schizophrenia (URS) participants exhibited poorer plasticity compared to first-line antipsychotic resistant [Cohen's d = 0.764, p = 0.004].

Conclusion: The results reaffirm the finding of impaired motor cortical plasticity in ARS. Additionally, we note that URS with a higher symptom burden, treatment resistance and poorer functioning had the poorest motor cortical plasticity. Future studies could explore the potential of cortical plasticity as a predictive, mechanistic, and theranostic biomarker.

Recent policies by the current United States (US) administration have had significant repercussions for science and the confidence of researchers to continue their work. In this Editorial, we explore the current and future impact of these political actions, and contrast them with the historical scientific developments underpinning schizophrenia research, both in Europe and the US. Europe has an opportunity to shape a future where science has the resources and security it needs to flourish ….

Background: Schizophrenia patho-etiology may involve endothelial inflammation and blood-brain barrier (BBB) dysregulation with cellular adhesion molecules (CAMs) as important mediators. CAMs are essential for cellular integrity but can show increased levels in inflammation. Cognitive dysfunction precedes and exists independently of psychotic symptoms in schizophrenia patients. CAMs could impact cognition through influence on BBB integrity. To gain insights into disease mechanisms and potential therapeutic targets, we explored the relationship between CAMs protein levels and neurocognitive tests in schizophrenia-spectrum disorders in the BeSt InTro study.

Methods: Seventy-one in- and out-patients underwent CAMs measurements and neuropsychological testing on a minimum of one time point: baseline, 6, 26, or 52 weeks. Cognitive domains included working memory, processing speed, verbal abilities, executive functions, and overall cognition. CAMs analyzed were neural CAMs: junctional adhesion molecule (JAM-A) and neural cadherin (N-CAD); vascular CAMs: intercellular adhesion molecule (ICAM)-1, vascular adhesion molecule (VCAM)-1, mucosal addressin cell adhesion molecule (MADCAM), and platelet (P)-selectin from fasting blood samples. Linear mixed effects models, adjusted for age, sex, body mass index, smoking, education, and drug naivety, estimated CAMs effect on cognitive outcome measures.

Results: N-CAD levels correlated positively with overall cognition (p = 0.002), working memory (p = 0.034), and executive functions (p = 0.0011). ICAM-1 levels correlated positively with overall cognition (p = 0.037). Conversely, JAM-A levels correlated negatively with executive functions (p = 0.021).

Conclusion: Associations between CAMs (N-CAD, ICAM-1, JAM-A) and neurocognitive tests suggest CAMs may impact cognition in schizophrenia. Contrary to our hypothesis, most associations between CAMs levels and cognitive tests were positive. Future research on mechanisms is mandatory.

Background: Violence in schizophrenia poses a major clinical and public health challenge. This study examined how core psychopathological features, conduct disorder (CD), and pharmacological treatment influence violent behavior by looking at the interaction among these variables. We also investigated the clinical differences between CD and non-CD patients.

Methods: 99 individuals with schizophrenia and with assaultive behaviors were randomly assigned in a double-blind design to clozapine, olanzapine, or haloperidol. Participants were further classified by presence or absence of CD. Clinical evaluation included the Positive, Excitement, and Depression factors of the Positive and Negative Syndrome Scale (PANSS), the Buss-Perry Aggression Questionnaire (BPAQ), and Barratt Impulsiveness Scale.

Results: Individuals with CD displayed higher trait aggression on the BPAQ and elevated endpoint PANSS Excitement, Hostility, and Anger scores compared with non-CD participants. Reductions in assaults were related to improvements in psychopathological measures in both the CD and non-CD groups, though these associations were stronger among non-CD participants. The relationship between symptom improvement and reduced aggression also varied by medication: in the haloperidol group, aggression reduction was closely associated with symptom improvement; in the clozapine group, no such association was found, suggesting a strong and direct anti-aggressive effect independent of symptom improvement; olanzapine showed an intermediate pattern.

Conclusion: These findings highlight the importance of interactions among symptoms, conduct disorder, and medication in determining violence. They also point to the multifactorial etiology of violence in patients with schizophrenia and to the need for tailored treatment strategies to effectively reduce violence, especially in high-risk population.

A significant minority of patients who present with psychosis have an underlying medical ("organic") cause. Some of these secondary causes are reversible; therefore, early detection is critical. Psychopathology may be informative during initial assessment to determine which patients are at an increased risk of having an underlying medical cause and should be prioritised for enhanced investigation. Through a pre-registered (CRD42024511546) systematic review and meta-analysis, we compared the psychopathology of patients with psychosis secondary to a medical cause compared to patients with primary psychosis as reported in case-control studies using PubMed from inception to September 2025. We identified 13 studies and a pooled sample size of 1564 individuals (primary psychosis = 781, secondary psychosis = 783). Poverty of speech (RR = 18.18, 95% CI = 1.43-231.5) and visual hallucinations (RR = 1.35, 95% CI 1.02-1.80) were more likely to be features of psychosis that was secondary to an underlying medical cause compared to a primary psychotic disorder. Conversely, auditory hallucinations (RR = 0.55, 95% CI = 0.50-0.61), thought insertion (RR = 0.24, 95% CI = 0.12-0.48), thought broadcast (RR = 0.30, 95% CI = 0.09-0.98), unspecified delusions (RR = 0.44, 95% CI = 0.30-0.66), delusions of persecution (RR = 0.72, 95% CI = 0.62-0.84), olfactory hallucinations (RR = 0.34, 95% CI = 0.18-0.63), and tactile hallucinations (RR = 0.26, 95% CI = 0.19-0.35) were more likely to be features of a primary psychosis. Findings underscore the clinical value of a comprehensive psychiatric assessment in patients with undifferentiated psychosis. Secondary psychoses show psychopathological differences, with certain symptoms potentially serving as 'red flags' for secondary causes. These indicators may assist clinicians in prioritising patients for further investigation.