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


METHODS
Random allocation to intervention or delayed treatment control with 4- and 12-week follow-up assessments.


METHODS
Counsellors from the Cannabis Information and Helpline (CIH), an Australian reactive telephone service, delivered the intervention to callers seeking treatment.


METHODS
A total of 160 participants were recruited by the CIH, with 110 participants completing the final follow-up assessment (69% retention).


METHODS
Cannabis use, dependence and related problems and other substance use were assessed at baseline and follow-up.


RESULTS
Intervention participants reported greater reductions in dependence symptoms [P < 0.001, d = 0.9 (0.5-1.3)] and related problems [P < 0.001, d = 0.5 (0.1-0.9)] compared with control participants at both follow-up assessments. Compared with control, intervention participants reported greater confidence to reduce cannabis use at 4 weeks [P = 0.002, d = 0.5 (0.1-0.9)], and in turn reported a greater percentage of abstinent days at 12 weeks [P = 0.019, d = 0.6 (0.2-1.0)].


CONCLUSIONS
A brief course of motivational interviewing plus cognitive behavioural therapy delivered by telephone can help to reduce cannabis dependence and promote abstinence in the short term.
National Cannabis Prevention and Information Centre, University of New South Wales, Randwick, NSW, Australia. p.gates@unsw.edu
Peter J
PJ
Gates
Melissa M
MM
Norberg
Jan
J
Copeland
Erol
E
Digiusto
D000328:Adult; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003376:Counseling; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D002189:Marijuana Abuse / Q000517:prevention & control*; D009042:Motivation; D010349:Patient Compliance; D019114:Remote Consultation / Q000379:methods*; D013689:Telephone / Q000706:statistics & numerical data*; D016896:Treatment Outcome