A Meta-Analysis of Adventure Therapy Outcomes and Moderators

This study reports on a meta-analytic review of 197 studies of adventure therapy participant outcomes (2,908 effect sizes, 206 unique samples). The short-term effect size for adventure therapy was moderate (g = .47) and larger than for alternative (.14) and no treatment (.08) comparison groups. There was little change during the lead-up (.09) and fol- low-up periods (.03) for adventure therapy, indicating long-term maintenance of the short-term gains. The short-term ad- venture therapy outcomes were significant for seven out of the eight outcome categories, with the strongest effects for clinical and self-concept measures, and the smallest effects for spirituality/morality. The only significant moderator of outcomes was a positive relationship with participant age. There was also evidence that adventure therapy studies have re- ported larger effects over time since the 1960s. Publication bias analyses indicated that the study may slightly underesti- mate true effects. Overall, the findings provide the most robust meta-analysis of the effects of adventure therapy to date. Thus, an effect size of approximately .5 is suggested as a benchmark for adventure therapy programs, although this should be adjusted according to the age group.