Cannabis consumption as a prognostic factor in schizophrenia.

Data were analysed from 62 schizophrenic patients between 18 and 30 years of age, treated at the community mental health centres in Navarra, who had relapsed and then completed a one-year follow-up study. Factors influencing the course of illness during follow-up were: continuing cannabis consumption; previous cannabis intake; non-compliance with treatment; and stress.