Cannabis use correlates with schizotypal personality traits in healthy students

The literature suggests that cannabis use and schizotypal traits both constitute risk factors for the later development of schizophrenia. However, their interrelationships remain to be evaluated. The present study examined the association between cannabis use and schizotypal traits in 232 healthy students who ranged in age from 18 to 25 years. All the students had completed the Schizotypal Personality Questionnaire and four of the Chapman Psychosis Proneness Scales: the Magical Ideation Scale; the Perceptual Aberration Scale; the Revised Physical Anhedonia Scale; and the Revised Social Anhedonia Scale. Subjects were divided into three groups according to cannabis use typology: those who had never used cannabis, those who were past or occasional users, and those who were regular users. Higher scores on the Schizotypal Personality Questionnaire and the Magical Ideation Scale characterized the regular and past or occasional users compared with those who had never used cannabis. The co-occurrence of cannabis use and schizotypal traits appeared to be independent of anxiety and depression dimensions. These data suggest that cannabis use and schizotypal traits have to be jointly considered in further longitudinal studies of schizophrenia risk factors.