SummaryObjectives: Cannabis is the most widely used illicit drug globally and its usehas been linked to an increased risk for psychotic disorders. An associationbetween cannabis consumption and psychotic symptoms was consistently reportedby several studies. This case-control study aimed to widen the currentfindings about the impact of cannabis exposure on the risk of psychosis, byinvestigating the pattern of cannabis consumption in a sample of first-episodeof psychosis (FEP) patients compared to healthy controls.Material and methods: 68 individuals who presented for the first time to mentalhealth services of Palermo (Italy) with an ICD-10 diagnosis of psychotic disordersand 74 healthy were enrolled as part of the Sicilian Genetics and Psychosisstudy. Psychopathological assessment and diagnosis were carried out bythe Schedule for Clinical Assessment in Neuropsychiatry (SCAN). Socio-demographicdata were collected by the modified version of the Medical ResearchCouncil (MRC) socio-demographic scale. All participants were interviewed usingthe Cannabis Experience Questionnaire – Modified Version to obtain a detailedassessment of lifetime patterns of cannabis and other illicit drug consumption.Logistic regression was applied to investigate the relationships between variousaspects of cannabis use (lifetime use, age at first use, duration, and frequency ofuse) and case-control status while controlling for potential confounders.Results: Patients started cannabis consumption about 3 years earlier thanthe control group (t = 3.1, p = 0.002) and were 8 times more likely to havingstarted using cannabis before 15 years (adjusted OR = 8.0, 95% CI 2.4-27)than controls. Furthermore cases were more likely to smoke more frequentlythan controls (adjusted OR = 4.4, 95% CI 1.08-18). We did not find a differencein duration of cannabis use between cases and controls.Conclusions: The findings suggest that cannabis exposure, and especiallydaily cannabis consumption, is associated with the risk for psychosis; however,the retrospective study design does not allow drawing firm conclusions aboutcausality.
|Number of pages||7|
|Journal||EVIDENCE-BASED PSYCHIATRIC CARE|
|Publication status||Published - 2017|