Is More Better? A Meta-Analysis of Dose and Efficacy in Face-to-Face Psychological Treatments for Problem and Disordered Gambling

A growing literature supports the efficacy of cognitive-behavioral therapies, motivational interventions, and personalized feedback to treat problem and disordered gambling. However, there is currently debate as to how much treatment is necessary. Some studies indicate that attending a greater number of sessions is related to enhanced therapeutic outcomes, while other studies indicate that one session produces equivalent therapeutic outcomes to multiple sessions. To contribute to this debate, meta-analysis was used to examine the relation between dose and outcome in studies of cognitive-behavioral, motivational, and personalized feedback interventions (both individual and group treatment formats were included). Fourteen studies of randomized controlled trials representing 1,203 participants across 19 treatment-control comparisons were identified. The intended treatment dose (i.e., the number of sessions prescribed to participants) across the 14 studies ranged from 1 to 30 sessions. Of the 10 studies reporting the received treatment dose (i.e., the number of sessions that participants attended), the weighted mean dose was 6.8 sessions (SD = 2.7). Both intended treatment dose and received treatment dose were positively related to outcome at posttreatment-as the number of sessions increased, so too did the magnitude of the between group effect size. There were an insufficient number of studies reporting outcome at long-term follow up to evaluate the relation between intended dose, received dose, and outcome. Discussion centers on several areas for future research on psychological treatments for problem and disordered gambling. Specific recommendations are made for researchers and practicing clinicians.