Abstract
BackgroundRobust evidence has demonstrated that cannabis use increases the risk to develop psychotic disorders. However, a limited number of studies have investigated if and how cannabis use influences psychopathology profiles at first episode psychosis (FEP).Based on the evidence that dopamine dysfunction contributes to explain positive symptoms in psychosis, and that the main cannabis’ psychoactive component, Δ9-Tetrahydrocannabinol (THC), modulates the dopamine system, we hypothesise that: 1) positive symptoms at FEP are more common among psychotic patients who used cannabis compared with never users; 2) this association is a dose-response relationship.MethodsWe analyzed a sample of 1130 FEP patients as part of the EUGEI study, recruited across six countries. The MRC Socio-demographic Schedule was used to collect sociodemographic information. Psychopathology was assessed with the OPerational CRITeria (OPCRIT), and symptom items were analyzed using Mplus to estimate a multidimensional model of psychosis. The Cannabis Experience Questionnaire modified version (CEQmv) was administered to collect information on cannabis, and different patterns of use were computed based on frequency of consumption and type of cannabis, as a proxy of exposure to THC.ResultsThe lifetime rate of cannabis use was 63%. Fifty-five percent of cannabis users consumed mostly high-potency cannabis, and 46% showed a daily frequency. Mixed-effects linear regression revealed that frequency of cannabis use was associated with the positive symptom dimension score. Daily users of high-potency cannabis presented with the strongest association (Β=0.19, 95%CI=0.02–0.38), even after gender, age, ethnicity, other drug use, and study site were controlled for.DiscussionOur results show that patients with a history of daily use of high potency cannabis express more positive symptoms at psychosis onset, even after taking into account other substance use and relevant sociodemographic factors.
Highlights
Interpretation of the efficacy of antipsychotic agents in treating schizophrenia using standard (Marder) Positive and Negative Syndrome Scale (PANSS) factors is confounded by moderate-to-high between-factor correlations
In a validation analysis using 12 separate clinical trials, we previously confirmed that the weighted uncorrelated PANSS score matrix (UPSM) coefficients had generalizable utility, yielding transformed PANSS factors with high specificity while retaining good levels of correlation with standard PANSS factors
In a new analysis of a pooled sample of 5 placebo-controlled trials (N=1,710 patients), K-means clustering of baseline UPSM factor scores in MATLAB was used to identify whether clinical sub-groups could be empirically derived that were characterized by predominant symptom severity in one or more of the transformed PANSS factor domains
Summary
Patients with schizophrenia have about 20 years shorter lifetime expectancy compared to healthy population. Discussion: Compared to the general population in Sweden there is an increased risk for diabetes in patients with schizophrenia, the prevalence of hypertonia is the same, 27 percent for 18 years old and elder, in the general population. Women and man with 10 percent respective 8 percent higher Even if both diabetes and tobacco use has a high prevalence in patients with schizophrenia, it may not be enough to explain the reduced lifetime expectancy in patients with schizophrenia This study indicates that metabolic syndrome and the risk factors it contains need to be further studied in order to find its association to early death in patients with schizophrenia. Markella Grigoriou*,1, Rachel Upthegrove[1], Lisa Bortolotti1 1University of Birmingham
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