Discussion
MDD, depressive, depression, depression/anxiety
REMISSION
The growing interest in exercise and adjunctive interventions for MDD calls for rigorous evaluation to determine their efficacy. Surf therapy and blue space have received theoretical and practical consideration as an adjunctive intervention for psychological symptoms in military populations [In addition to the lasting effects of Surf and Hike Therapy, findings supported immediate effects on depression/anxiety symptoms. Specifically, there were significant within-session improvements in depression/anxiety for both interventions. The pattern of results mirrored the changes documented in prior surf therapy research [Contrary to expectations, there was little evidence for the enhanced effects of Surf Therapy relative to Hike Therapy. Although the Surf Therapy group reported less severe depressive symptoms during the intervention period, the trajectories of symptom change were parallel between the intervention groups across time, as well as within session. The only significant between-group difference was in MDD remission at the 3-month follow-up, for which service members in Surf Therapy (74% without MDD) were more likely to achieve MDD remission compared with those in Hike Therapy (47% without MDD). However, neither condition showed significant within-group changes from postprogram to 3-month follow-up. It should be noted that participants in Hike Therapy had more missing data at the 3-month follow-up, which may have affected the MDD remission rates between the conditions at this time point.The mixed support for the blue space framework is reflected in research [Equally possible is that surf and hike therapies produced similar outcomes because they both align with clinical theories and approaches shown to effectively treat depression. For example, surf and hike therapies could be considered as forms of behavioral activation [Study results should be interpreted within the context of its limitations. The sample consisted of service members, so results may not generalize to other populations. Most participants self-reported at least moderate engagement in physical activity at preprogram; individuals who regularly engage in physical activity may be likely to choose and benefit from activity-based approaches [This research also has strengths that advance the fields of surf therapy and activity-based intervention research. Notably, this study implemented an RCT design with gold standard clinician-administered measures. The RCT included an active comparison group to determine whether there were unique effects of water-based activities on symptoms of MDD. Further, all participants met diagnostic criteria for MDD, allowing outcomes to be evaluated within a clinical population for whom they may be particularly beneficial [