%0 Journal Article %@ 1438-8871 %I Gunther Eysenbach %V 15 %N 2 %P e26 %T Effectiveness of a Self-Guided Web-Based Cannabis Treatment Program: Randomized Controlled Trial %A Rooke,Sally %A Copeland,Jan %A Norberg,Melissa %A Hine,Donald %A McCambridge,Jim %+ University of New South Wales, 22-32 King Street, Randwick, 2031, Australia, 61 293850450 ext 50450, s.rooke@unsw.edu.au %K marijuana %K Internet intervention %K computer-assisted therapy %K addiction %K randomized controlled trial %D 2013 %7 15.02.2013 %9 Original Paper %J J Med Internet Res %G English %X Background: Self-help strategies offer a promising way to address problems with access to and stigma associated with face-to-face drug and alcohol treatment, and the Internet provides an excellent delivery mode for such strategies. To date, no study has tested the effectiveness of a fully self-guided web-based treatment for cannabis use and related problems. Objectives: The current study was a two-armed randomized controlled trial aimed at testing the effectiveness of Reduce Your Use, a fully self-guided web-based treatment program for cannabis use disorder consisting of 6 modules based on cognitive, motivational, and behavioral principles. Methods: 225 individuals who wanted to cease or reduce their cannabis use were recruited using both online and offline advertising methods and were randomly assigned to receive: (1) the web-based intervention, or (2) a control condition consisting of 6 modules of web-based educational information on cannabis. Assessments of cannabis use, dependence symptoms, and abuse symptoms were conducted through online questionnaires at baseline, and at 6-week and 3-month follow-ups. Two sets of data analyses were undertaken—complier average causal effect (CACE) modeling and intention to treat (ITT). Results: Two thirds (149) of the participants completed the 6-week postintervention assessment, while 122 (54%) completed the 3-month follow-up assessment. Participants in the intervention group completed an average of 3.5 of the 6 modules. The CACE analysis revealed that at 6 weeks, the experimental group reported significantly fewer days of cannabis use during the past month (P=.02), significantly lower past-month quantity of cannabis use (P=.01), and significantly fewer symptoms of cannabis abuse (P=.047) relative to controls. Cannabis dependence symptoms (number and severity) and past-month abstinence did not differ significantly between groups (Ps>.05). Findings at 3 months were similar, except that the experimental group reported significantly fewer and less severe cannabis dependence symptoms (Ps<.05), and past-month quantity of cannabis consumed no longer differed significantly between groups (P=.16). ITT analyses yielded similar outcomes. Conclusion: Findings suggest that web-based interventions may be an effective means of treating uncomplicated cannabis use and related problems and reducing the public health burden of cannabis use disorders. Trial registration: ACTRN12609000856213, Australian New Zealand Clinical Trials Registry. %M 23470329 %R 10.2196/jmir.2256 %U http://www.jmir.org/2013/2/e26/ %U https://doi.org/10.2196/jmir.2256 %U http://www.ncbi.nlm.nih.gov/pubmed/23470329