The Synergistic Effects Of Exercise In Combination With Other Antidepressant Therapies.

Abstract

PURPOSE: Major depressive disorder (MDD) is a global public-health concern. Current anti-depressant treatments are far from satisfactory leaving half of patients undertreated. Research has found exercise alone to be an effective treatment for people suffering with mild to moderate depression however its mechanism of action remains unclear. There is also a lack of research investigating the effects of exercise in combination with other conventional antidepressant therapies in people suffering with severe depression such as MDD. The aim of this study is twofold: first, to investigate the effects of an eight week exercise program in combination with antidepressant medication and intensive group therapy in improving depressive symptoms, anxiety and sleep quality; secondly, to identify changes in brain derived neurotrophic factor (BDNF) which is known to be reduced in people suffering with MDD. METHODS: Sixteen sedentary participants were recruited from the Lakeridge Mental Health Day Treatment (LMHDT) program in Oshawa, Ontario, Canada. All participants had a clinical diagnosis of MDD based on DSM-IV criteria and an unstructured clinical interview conducted by hospital psychiatrists. Participants were assigned either to an eight week, supervised, moderate intensity exercise program plus LMHDT group or the LMHDT only group. Depression scores were determined using the Beck Depression Inventory (BDI), sleep quality by the Pittsburgh Sleep Quality Index (PSQI) and plasma BDNF was quantified by ELISA. All variables were measured at baseline and again at eight weeks. RESULTS: Following the eight weeks of combination treatment the exercise group showed a greater decrease in depression scores, F (1,14)=10.18, p=0.007, d=2.04, a greater improvement in sleep quality, F (1,14)=4.81, p=0.046, d=1.28 and a greater increase in plasma BDNF concentration, F(1,14)=12.47, p=0.003, d = 1.99 compared to the non-exercise group. The exercise group also had a greater decrease in anxiety scores although there was no significant difference between the two groups, F (1,14)=0.25, p=0.623, d=.33. CONCLUSIONS: This project has the potential to provide a tool to improve exercise prescription and to guide development of combined treatment approaches in order to optimize treatment outcomes for people suffering with MDD.