Does cognitive-behavioral treatment affect putative mechanisms of change among individuals with problem gambling? A systematic review and exploratory meta-analysis

•Participants in CBT had more favorable gambling cognitions at posttreatment than minimal/no treatment.•Participants in CBT had more coping behaviors at posttreatment than minimal/no treatment.•Participants in CBT had more self-efficacy at posttreatment than minimal or no treatment control.•Results provide preliminary support for effectiveness of CBT on three mechanisms of change.•Significant heterogeneity was present in the magnitude of effect sizes.•Significant inconsistency in outcome measurement was noted. Objective: The current study was a systematic review and meta-analysis of cognitive behavioral treatment (CBT) for problem gambling and gambling disorder and whether it produced different outcomes than minimal or no treatment controls on three putative change mechanisms: 1) gambling cognitions, 2) coping, and 3) self-efficacy. Method: Studies were identified from five bibliographic databases (i.e., Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, PsycINFO, and PubMed). Included studies were randomized controlled trials of CBT that included posttreatment data on putative mechanisms. Between-group Hedges’s g effect sizes were calculated to examine outcomes of CBT relative to minimal or no treatment control on gambling cognitions, coping, and self-efficacy at posttreatment. Risk of bias was determined using the Cochrane Risk of Bias tool. Results: Fifteen studies, representing 1,536 participants, were eligible for analysis. Participants in CBT had more favorable gambling cognitions (g = -0.41), coping behaviors (g = 0.27), and self-efficacy (g = 1.12) at posttreatment than minimal or no treatment control. Conclusions: Results of the current study provided preliminary support for the effectiveness of CBT on three putative mechanisms of change among individuals experiencing problem gambling and gambling disorder. Although the results were promising, there was significant heterogeneity in the magnitude of effect sizes for all three outcomes, and outcomes were not consistently assessed with psychometrically established assessment tools.