Family motivational intervention for reducing cannabis use in recent-onset schizophrenia

Cannabis use in highly prevalent among young adults with recent-onset schizophrenia and has been associated with an adverse course of the illness. Despite these association, the evidence for effective interventions for treating cannabis use in patients with psychosis is limited. This thesis focuses on the short and long term effects of a novel family-based intervention for schizophrenia, called Family Motivational Intervention (FMI); a training in interactions skills and motivational interviewing skills for parents to reduce cannabis use in young adults with recent-onset schizophrenia. In a randomized controlled trial (RCT) we demonstrated that FMI was significant more effective than Routine Family Support (RFS) in reducing the frequency and quantity of cannabis use in patients at 3- and 15-month follow-up. Findings were inconsistent with regard to the long-term superiority of FMI over RFS in reducing parents’ levels of distress and sense of burden. In the trial we also demonstrated that FMI is a feasible training method for increasing motivational interviewing skills in parents.