title: A controlled trial of an internet-based intervention program for cannabis users.
abstract: In the last decade, several programs for the treatment of cannabis-related disorders were developed. Until now, no information is available on the efficacy of Internet-based counseling approaches for this target group. This article describes the evaluation of "quit the shit," a web-based intervention developed to help young people to quit or reduce their cannabis use significantly. Cannabis users seeking web-based treatment were included in a two-arm controlled trial conducted on a website for drug-related information and prevention. After the baseline assessment, members of the treatment condition were randomized to a 50-day intervention program. Other trial participants were put on a waiting list. A post-test was conducted 3 months after randomization. Of all 1,292 subjects included in the trial, a total of 206 participants took part at the post-test. Per-protocol- and intention-to-treat analyses were conducted. Members of the treatment condition showed a significantly stronger reduction in cannabis use (primary outcome) than the control group. In the per-protocol analyses, moderate-to-strong effects were found for the reduction of the frequency and the reduction of the quantity of consumed cannabis. Small-to-moderate effects were observed on the secondary outcomes (use-related self-efficacy, anxiety, depression, and life satisfaction). Despite limitations concerning the interpretation of the results, the intervention seems to offer an effective treatment option for persons with cannabis-related problems.
authors.affiliation: Delphi-Gesellschaft für Forschung, Beratung und Projektentwicklung, Berlin, Germany. tossmann@delphi-gesellschaft.de
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Tossmann
authors.forename: Benjamin
authors.initials: B
authors.lastname: Jonas
authors.forename: Marc-Dennan
authors.initials: MD
authors.lastname: Tensil
authors.forename: Peter
authors.initials: P
authors.lastname: Lang
authors.forename: Evelin
authors.initials: E
authors.lastname: Strüber
mesh_terms: D000293:Adolescent; D000328:Adult; D003376:Counseling / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020407:Internet; D008297:Male; D002189:Marijuana Abuse / Q000523:psychology / Q000628:therapy*; D010349:Patient Compliance / Q000706:statistics & numerical data; D015397:Program Evaluation; D018709:Statistics, Nonparametric; D017216:Telemedicine / Q000379:methods*; D013813:Therapy, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult