Cannabis use and symptom severity in individuals at ultra high risk for psychosis: a meta-analysis
R Carney, J Cotter, J Firth, T Bradshaw, AR Yung
ACTA PSYCHIATRICA SCANDINAVICA | WILEY | Published : 2017
OBJECTIVE: We aimed to assess whether individuals at ultra high risk (UHR) for psychosis have higher rates of cannabis use and cannabis use disorders (CUDs) than non-UHR individuals and determine whether UHR cannabis users have more severe psychotic experiences than non-users. METHOD: We conducted a meta-analysis of studies reporting cannabis use in the UHR group and/or positive or negative symptoms among UHR cannabis users and non-users. Logit event rates were calculated for cannabis use, in addition to odds ratios to assess the difference between UHR and controls. Severity of clinical symptoms in UHR cannabis users and non-users was compared using Hedges' g. RESULTS: Thirty unique studies ..View full abstract
Awarded by Economic and Social Research Council
Awarded by Medical Research Council
This work was supported by the Economic and Social Research Council [ES/J500094/1].