Aims-Achieving abstinence in the treatment of marijuana dependence has been difficult. To date the most successful treatments have included combinations of motivation enhancement treatment (MET) plus cognitive-behavioral coping skills training (CBT) and/or contingency management (ContM) approaches. Although these treatment approaches are theoretically based, their mechanisms of action have not been fully explored. The purpose of the present study was to explore mechanisms of behavior change from a marijuana treatment trial in which cognitive-behavioral treatment (CBT) and contingency management (ContM) were evaluated separately and in combination.
Design-A dismantling design was used in the context of a randomized clinical trial.Setting-The setting was an outpatient treatment research facility located in a university medical center.Participants-Participants were 240 adult marijuana smokers, meeting criteria for cannabis dependence.Interventions-Participants were assigned to one of four 9-week treatment conditions: a case management control condition, MET/CBT coping skills training, contingency management (ContM), and MET/CBT+ContM.Measurements-Outcome measures were total 90-day abstinence, recorded every 90 days for 12 months posttreatment.Findings-Regardless of treatment condition, abstinence in near-term follow-ups was best predicted by abstinence during treatment, but long-term abstinence was predicted by use of coping skills and especially by posttreatment self-efficacy for abstinence.Conclusions-It was concluded that the most efficacious treatments for marijuana dependence are likely to be those that increase self-efficacy.
KeywordsMarijuana dependence; contingency management; cognitive-behavioral treatment; self-efficacy; coping skills; treatment mechanisms Marijuana is the most widely used illicit drug in the U.S.A. [1]. Despite recent attention to the treatment of marijuana dependence (e.g., [2]), prolonged abstinence has been difficult to Correspondence concerning this article may be addressed to: Mark D. Litt, Ph.D., Division of Behavioral Sciences and Community Health, MC3910, University of Connecticut Health Center, Farmington, CT 06030. Electronic mail should be sent to E-mail: Litt@nso.uchc.edu..
NIH Public Access
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript achieve [2,3]. There is thus a pressing need to determine what mechanisms of treatment lead to behavior change in this population.Several treatment strategies offer promise in the treatment of marijuana dependence, namely cognitive-behavioral coping skills training (CBT), motivational enhancement (MET), contingency management, or a combination of these. In the largest controlled trial of treatment for marijuana dependence to date, the multi-site Marijuana Treatment Project (MTP) showed results indicating that nine sessions of combined MET and CBT were superior to two sessions of MET, and both were superior to a delayed treatment control group [2]. The highest abstinence rate achieved was 23% at 4-month foll...