Effects Of Ptsd And Mdd Comorbidity On Psychological Changes During Surf Therapy Sessions

PTSD is more likely to be accompanied by another psychological disorder (most commonly depression) than to occur alone, and those with this comorbidity exhibit more severe psychological outcomes compared to those with a single disorder. Exercise-based interventions that occur in the natural environment, such as surf therapy, have preliminarily been shown to improve psychological outcomes in service members/veterans with PTSD or major depressive disorder (MDD); however, previous research has not yet examined the effectiveness of these programs for those with both disorders. PURPOSE: This study compared changes in depression/anxiety and positive affect during surf therapy sessions between active duty service members with comorbid PTSD and MDD and those with either disorder alone. METHODS: Probable PTSD and MDD diagnoses were determined using Diagnostic and Statistical Manual of Mental Disorders, 5th Edition criteria applied to baseline self-report measures. Study outcomes were assessed using validated self-reports (Patient Health Questionnaire-4 and Positive Affect Schedule) completed before and after each of 6 weekly surf therapy sessions. Longitudinal repeated measures data was analyzed using multilevel modeling. RESULTS: From pre-to-post session, both the comorbid and single disorder groups reported significant improvements in symptoms of depression/anxiety and positive affect (ps < .001). However, those with comorbid PTSD and MDD experienced significantly greater reductions in depression/anxiety (β = −1.22, p = .028) and significantly greater improvements in positive affect (β = 3.94, p = .046) compared with the single disorder group. CONCLUSIONS: Surf therapy appears to have global effects on psychological symptom reduction, and may be a useful adjunctive intervention for the treatment of comorbid PTSD and MDD in both clinical and community health settings. Supported by the U.S. Navy Bureau of Medicine and Surgery under work unit no. N1600.