Cannabis use as a predictor for relapse in First Episode Psychosis: A three-year follow up study

Presentation First Author: 
Tabea Schoeler

Background. The emergence of a relapse following a first episode psychosis (FEP) is common in patients suffering from the disorder. Although cannabis represents one potential factor that predicts relapse, conclusions from current findings are limited given the cross-sectional nature of study designs and the inclusion of patients that are at different stages of their illness. Methods. Ninety-five FEP participants presenting to an inner city service in London were assessed at follow-up. The outcome of interest was defined as relapse of psychosis defined as admission to hospital within three years following their FEP. The effect of ongoing cannabis use was analysed employing logistic and linear regression analysis in SPSS, while controlling for confounders. Results. Forty-seven percent of the FEP cohort experienced an admission to a psychiatric hospital within the follow-up period. Ongoing cannabis use was more frequent in patients that relapsed compared to non-relapsing patients (62% vs. 38%). When controlled for gender, age of onset of psychosis and premorbid cannabis use, ongoing cannabis use was significantly associated with increased odds of admission (OR=4.26; 95%CI=1.4, 12.9) and an increase in number of admissions (_=.37; 95%CI=2.8, 1.3) within the follow up period. Discussion. Within three years following the onset, FEP patients that continued consuming cannabis were at a 4-fold higher risk of relapse and were more frequently admitted to psychiatric hospitals when compared to non-users. This is consistent with previous studies and emphasizes the importance to target cannabis use in early intervention services to improve longer-term outcome in psychosis.

Conference Name: 
Presentation Date: 
January, 2015
Additional Authors: 
Natalia Petros - Irena Behlke - Marta DiForti - Robin Murray - Sagnik Bhattacharyya
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