17.1 A RANDOMIZED CONTROLLED TRIAL OF CANNABIDIOL IN SCHIZOPHRENIA

BACKGROUND: Both preclinical and human research suggest that cannabidiol (CBD) has antipsychotic properties. This study assessed the safety and effectiveness of CBD in patients with schizophrenia. METHODS: Patients with schizophrenia (n=88) were randomized to receive CBD (1000 mg/day) or placebo alongside their existing antipsychotic medication for 6 weeks. Participants were assessed before and after treatment using the PANSS, BACS, GAF scales, and the CGI Improvement and Severity scales. RESULTS: Compared those given placebo, patients treated with CBD had lower levels of positive psychotic symptoms (PANSS; p=0.02), and were more likely to have been rated by clinicians as improved (CGI-I; p=0.02) and as not severely unwell (CGI-S; p=0.04). Patients who received CBD also showed trends for greater improvements in cognitive performance (BACS; p=0.07) and in overall functioning (GAF; p=0.08). There was no difference in the frequency of CBD of adverse events between CBD and placebo. DISCUSSION: These data suggest that CBD has beneficial effects in patients with schizophrenia and is not associated with significant adverse effects.