Time Changes In Cannabis Use In A Cohort Of Patients With First Episode Psychosis And Association With Clinical And Social Outcome. A Five-Year Follow-Up Of The Opus Cohort

Presentation First Author: 
Merete Nordentoft

The aim was to assess whether abuse of cannabis in patients with first episode psychosis influences the clinical and social outcome. Methods: A total of 547 patients with first episode schizophrenia spectrum disorder were included in the OPUS trial, and 301 patients participated in the five year follow-up. Information on use of cannabis, clinical and social factors and service use was collected at entry and after five years from clinical interviews with SCAN, SAPS and SANS. Both cross-sectional and longitudinal correlates of frequent cannabis use and clinical and social outcomes were estimated. Results: At entry, cannabis abuse was significantly correlated with lower age(24.9 years vs. 27.1 years), lower educational level, higher level of disorganized symptoms, and a lower level of social functioning. At the five year follow up, frequent cannabis users had a significantly higher level of psychotic symptoms and lower level of social functioning compared to the rest of the patients. Those who stopped using cannabis between entry and five year follow-up had a significantly lower level of psychotic symptoms at five year follow-up compared to those who had a continuous use of cannabis. This association was significant even after controlling for baseline level of psychotic symptoms, but was only marginally significant when adjusted for compliance with medication. Conclusions: Cannabis use was associated with lower age of onset. Continuous cannabis use was associated with higher level of psychotic symptoms after five years. The difference in psychotic symptoms after five years was partially explained by difference in compliance with medication

Conference Name: 
Presentation Date: 
January, 2013
Additional Authors: 
Merete Nordentoft, Laura Clausen, Carsten Hjorthøj, Anne Thorup, Pia Jeppesen, Mette Bertelsen
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