The efficacy of motivational interviewing for disordered gambling: systematic review and meta-analysis

Motivational interviewing is a client-centered therapeutic intervention that aims to resolve ambivalence toward change. We conducted a systematic review and meta-analysis on the efficacy of motivational interviewing, compared to non-motivational interviewing controls, in the treatment of disordered gambling. Electronic databases were searched for randomized controlled trials that evaluated change in gambling behavior using motivational interviewing in adult disordered gamblers. The primary outcomes were the weighted mean difference (WMD) for change in average days gambled per month and average dollars lost per month. The search strategy yielded 447 articles, of which 20 met criteria for full text review. Overall, 8 studies (N=730) fulfilled the inclusion criteria for systematic review and 5 (N=477) were included in the meta-analysis. Motivational interviewing was associated with significant reduction in gambling frequency up to a year after treatment delivery. For gambling expenditure, motivational interviewing yielded significant reductions in dollars spent gambling compared to non-motivational controls at post-treatment only (1-3 months). Overall, the results of this review suggest that motivational interviewing is an efficacious style of therapy for disordered gambling in the short term. Whether treatment effects are maintained over time remains unclear.