26 research outputs found

    Pilot study of the relationship between psychotic manifestations and living environment

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    The study of subclinical psychotic manifestations (quantitative schizotypy) represents clinical and public health issues. These manifestations are more common than schizophrenia or depression, but rarely identified while it impacts the quality of life. Screening schizotypy in the general population would make it possible to propose prevention strategies. The objectives of the present research is to better understand the determinants and mechanisms of schizotypy in order to identify population..

    Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals

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    Background: The association between cannabis use and positive symptoms in schizophrenia spectrum disorders is well documented, especially via meta-analyses. Yet, findings are inconsistent regarding negative symptoms, while other dimensions such as disorganization, depression, and excitement, have not been investigated. In addition, meta-analyses use aggregated data discarding important confounding variables which is a source of bias. Methods: PubMed, ScienceDirect and PsycINFO were used to search for publications from inception to September 27, 2022. We contacted the authors of relevant studies to extract raw datasets and perform an Individual Participant Data meta-analysis (IPDMA). Inclusion criteria were: psychopathology of individuals with schizophrenia spectrum disorders assessed by the Positive and Negative Syndrome Scale (PANSS); cannabis-users had to either have a diagnosis of cannabis use disorder or use cannabis at least twice a week. The main outcomes were the PANSS subscores extracted via the 3-factor (positive, negative and general) and 5-factor (positive, negative, disorganization, depression, excitement) structures. Preregistration is accessible via Prospero: ID CRD42022329172. Findings: Among the 1149 identified studies, 65 were eligible and 21 datasets were shared, totaling 3677 IPD and 3053 complete cases. The adjusted multivariate analysis revealed that relative to non-use, cannabis use was associated with higher severity of positive dimension (3-factor: Adjusted Mean Difference, aMD = 0.34, 95% Confidence Interval, CI = [0.03; 0.66]; 5-factor: aMD = 0.38, 95% CI = [0.08; 0.63]), lower severity of negative dimension (3-factor: aMD = -0.49, 95% CI [-0.90; -0.09]; 5-factor: aMD = -0.50, 95% CI = [-0.91; -0.08]), higher severity of excitement dimension (aMD = 0.16, 95% CI = [0.03; 0.28]). No association was found between cannabis use and disorganization (aMD = -0.13, 95% CI = [-0.42; 0.17]) or depression (aMD = -0.14, 95% CI = [-0.34; 0.06]). Interpretation: No causal relationship can be inferred from the current results. The findings could be in favor of both a detrimental and beneficial effect of cannabis on positive and negative symptoms, respectively. Longitudinal designs are needed to understand the role of cannabis is this association. The reported effect sizes are small and CIs are wide, the interpretation of findings should be taken with caution

    The continuity of effect of schizophrenia polygenic risk score and patterns of cannabis use on transdiagnostic symptom dimensions at first-episode psychosis: findings from the EU-GEI study

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    Abstract: Diagnostic categories do not completely reflect the heterogeneous expression of psychosis. Using data from the EU-GEI study, we evaluated the impact of schizophrenia polygenic risk score (SZ-PRS) and patterns of cannabis use on the transdiagnostic expression of psychosis. We analysed first-episode psychosis patients (FEP) and controls, generating transdiagnostic dimensions of psychotic symptoms and experiences using item response bi-factor modelling. Linear regression was used to test the associations between these dimensions and SZ-PRS, as well as the combined effect of SZ-PRS and cannabis use on the dimensions of positive psychotic symptoms and experiences. We found associations between SZ-PRS and (1) both negative (B = 0.18; 95%CI 0.03–0.33) and positive (B = 0.19; 95%CI 0.03–0.35) symptom dimensions in 617 FEP patients, regardless of their categorical diagnosis; and (2) all the psychotic experience dimensions in 979 controls. We did not observe associations between SZ-PRS and the general and affective dimensions in FEP. Daily and current cannabis use were associated with the positive dimensions in FEP (B = 0.31; 95%CI 0.11–0.52) and in controls (B = 0.26; 95%CI 0.06–0.46), over and above SZ-PRS. We provide evidence that genetic liability to schizophrenia and cannabis use map onto transdiagnostic symptom dimensions, supporting the validity and utility of the dimensional representation of psychosis. In our sample, genetic liability to schizophrenia correlated with more severe psychosis presentation, and cannabis use conferred risk to positive symptomatology beyond the genetic risk. Our findings support the hypothesis that psychotic experiences in the general population have similar genetic substrates as clinical disorders

    Prevalence of psychotic disorders in an urban area of France

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    International audienceAbstractBackgroundMost data on the prevalence of psychotic disorders is limited to global estimates or restricted to schizophrenia. Consequently, there is limited information available about the prevalence of psychotic disorders more widely and outwith age and sex - specific prevalence values. The objective of this study is to provide period prevalence estimates, detailed by gender and age groups, for treated psychotic disorders in an adult population (aged 18 years and over) from an urban area in France.MethodsProspective reporting of cases treated over an 8-week period complemented by several methods estimating the number of potentially missed cases, including a leakage study. The study took place in an urban, well defined catchment area, with a population of 67 430 at risk subjects living in the east of a Paris suburb.ResultsThe observed prevalence was of 3.72 per 1000 subjects at risk; after adjustment for potentially lost cases the estimate was of 4.60 per 1000 subjects at risk. Observed prevalence was higher in men (4.71 per 1000, Relative Risk = 1.68) and in the 35–45 age-band (6.05 per 1000, Relative Risk = 1.93).ConclusionGlobal prevalence estimates of psychotic disorders in this study are in line with expected values based on studies conducted in other countries. Careful consideration of the causes of missed cases and gathering of complementary data are essential and could result in significant changes in prevalence estimates. Detailed estimates (by age) suggest that treated psychosis might not be a lifelong condition
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