Cannabis use and abstention in first-episode psychosis: the participants’ view

Cannabis use has been identified as a prognostic factor for poor outcome in first-episode psychosis (FEP). The research aimed to understand the factors that motivate or inhibit the use of cannabis in people with first-episode psychosis. Thirty first-episode psychosis patients (18 cannabis users and 12 abstainers) were interviewed using qualitative semi-structured methods in order to investigate the self reported factors perceived to influence cannabis abstention, initiation, continued use and consumption change. Interviews were transcribed verbatim and analysed using grounded theory based methods. Psychosis specific reasons were not found to be motivationally salient for the initiation or continued use of cannabis, but were found to be important for decreased consumption and cessation. Mental health concerns, such as the impact of cannabis on relapse and psychotic symptom exacerbation were also found to motivate abstention. Psychosis related reasons do not appear to motivate the initial or continued use of cannabis, although thedeleterious effect of cannabis to mental health may promote decreased cannabis consumption, cessation and abstinence following the onset of psychosis. Therefore substance use early interventions for this population should aim to increase emphasis on the potential harms of cannabis to mental health.