Cannabis use predicts shorter duration of untreated psychosis and lower levels of negative symptoms in first-episode psychosis: a South African study.

Maybe Frank won't be so bad off after all...

We’ve heard so many studies predicting that cannabis use leads to or exacerbates psychoses.  This study out of South Africa appears to predict just the opposite – that cannabis use may shorten and decrease episodes of psychoses!

Department of Psychiatry, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, South Africa.

Abstract

OBJECTIVE: Cannabis use/abuse is a common co-morbid problem in patients experiencing a first episode of psychotic illness (FEP). The relationship between the clinical presentation of FEP and cannabis abuse is complex and warrants further investigation, especially within the South African context.

METHOD: We tested associations between recent/current cannabis use and duration of untreated psychosis (DUP), age of onset (AO), PANSS-rated (Positive and Negative Syndrome Scale) positive, negative and general psychopathology symptoms and depressive symptoms (Calgary Depression Scale for Schizophrenia) in a sample of 54 patients with FEP.

RESULTS: Mean DUP was 34.4 weeks, while mean AO was 24.7 years. Co-morbid cannabis use occurred in 35% of the sample and was significantly associated with shorter DUP (Mann-Whitney U, p=0.026). While not significant, there was also a trend association between cannabis use and lower negative symptoms (Mann-Whitney U, p=0.051).

CONCLUSION: Current/recent cannabis use was associated with clinical features of psychosis onset that previously have been associated with better outcome. Medium and long-term outcome for cannabis users however, is likely to depend on whether or not cannabis use is ongoing.