Randomized controlled trial of a novel cannabis use intervention delivered by telephone

Aims To evaluate the efficacy of a telephone‐based intervention consisting of four sessions of motivational interviewing (MI) and cognitive behavioural therapy (CBT) designed to assist individuals to reduce their cannabis use and related problems. Design Random allocation to intervention or delayed treatment control with 4‐ and 12‐week follow‐up assessments. Setting Counsellors from the Cannabis Information and Helpline (CIH), an Australian reactive telephone service, delivered the intervention to callers seeking treatment. Participants A total of 160 participants were recruited by the CIH, with 110 participants completing the final follow‐up assessment (69% retention). Measurements Cannabis use, dependence and related problems and other substance use were assessed at baseline and follow‐up. Findings Intervention participants reported greater reductions in dependence symptoms [P