The effect of aerobic exercise alone and in combination with cognitive behavioural therapy on obsessive compulsive disorder: A randomized control study

PURPOSE: Cognitive behavioural therapy (CBT) has been found to be an effective treatment for OCD, but there remains a significant proportion of individuals who fail to show a treatment response. Aerobic exercise has previously been associated with decreases in anxiety and depression, as well as improvements in OCD symptoms in small-scale studies. The purpose of the present research was to use a randomized control trial design to examine the effects of exercise alone and in combination with CBT, on OCD symptoms and secondary symptoms. METHOD: 125 participants were randomly assigned to one of four treatment groups: waitlist control, exercise, CBT, and CBT with exercise. OCD symptom severity was measured at four points over the course of treatment, secondary outcome measures were gathered at three points over treatment. RESULTS: CBT alone and combined with exercise was associated with significantly greater OCD symptom reduction than exercise alone or the control groups. Total exercise frequency predicted OCD symptom reduction in the groups in which exercise was measured. Group membership did not significantly predict reductions in secondary outcome measures. CONCLUSION: Exercise frequency, rather than the presence or absence of exercise, appears to predict OCD symptom reduction, as did participation in CBT.