Comparison of extended versus brief treatments for marijuana use

Adult marijuana users (N = 292) seeking treatment were randomly assigned to an extended 14-session cognitive-behavioral group treatment (relapse preve ntion support group; RPSG), a brief 2-session individual treatment using mo tivational interviewing (individualized assessment and intervention; IAI), or a 4-month delayed treatment control (DTC) condition. Results indicated t hat marijuana use, dependence symptoms, and negative consequences were redu ced significantly in relation to pretreatment levels at 1-, 4-, 7-, 13-, an d 16-month follow-ups. Participants in the RPSG and TAI treatments showed s ignificantly and substantially greater improvement than DTC participants at the 4-month follow-up. There were net significant differences between RPSG and IAI outcomes at any follow-up. The relative efficacy of brief versus e xtended interventions for chronic marijuana-using adults is discussed.