Randomized controlled trial of group motivational interviewing for veterans with substance use disorders

Background: Motivational interviewing delivered in a group format is understudied yet promising as a treatment for substance use disorders (SUD). We evaluated the efficacy of group motivational interviewing (GMI) relative to a treatment-control (TCC) for enhancing treatment and self-help engagement and decreasing alcohol and drug use among veterans with SUD and co-existing psychiatric disorders. Method: Veterans (n = 118) with alcohol use disorder were recruited within an outpatient SUD treatment program and randomized to GMI or TCC upon program entry. Alcohol use, SUD treatment, and 12-step session attendance were primary outcomes. Drug use days was the secondary outcome. Participants were assessed at baseline and at one-and three-month follow-up. Results: Significant differences were observed between GMI and TCC for binge drinking at both one (RR = .74; 95 % CI [.58, .94]) and three-month follow-up (RR = .74; 95 % CI [.59, .91]). At three-month follow-up, significant differences between treatment conditions were observed for alcohol use days (RR = .79; 95 % CI [.67, .94]), number of SUD treatment sessions (RR = 2.53; 95 % CI [1.99, 3.22]), and 12-step sessions attended (RR = 1.64; 95 % CI [1.35-1.98]). Similarly, we observed significant effects for GMI on reducing alcohol consumption in standard drinks (RR = .49; 95 % CI [.25, .95]). Drug use days declined at each follow-up, with no significant differences between treatment conditions. Conclusions: GMI delivered at SUD treatment program entry enhanced treatment session and 12-step group attendance and lowered alcohol consumption among outpatient Veterans. Future research should study how GMI works and its effectiveness in SUD treatment settings.