In recent years, physical exercise has shown some promising results as an adjuvant therapy for several psychological disorders. However, and due to the different populations, settings and exercise programs, not all studies have shown a positive association.

To assess the effect of a moderate intensity 12 week exercise program on depression and functional parameters in a population sample of patients with non-remitted Major Depressive Disorder (MDD).

Study design Prospective, randomized, two-arm, parallel assignment. Population 150 individuals diagnosed with MDD according to DSM-IV criteria, taking combined therapy in doses considered appropriate for at least 9 months, without showing clinical remission, defined as having an HAMD17 total score ≤ 7, attending the out-patient psychiatry clinic, were initially screened through an interview with a psychiatrist. Those meeting study criteria were randomized to one of two groups: control (N = 11) and aerobic exercise (N = 22). Study protocol Exercise group: moderate intensity exercise program for 12 weeks, in addition to their usual pharmacological therapy. Control group: regular daily activities and their usual pharmacological therapy. Assessed parameters HAMD17, Beck Depression Inventory (BDI), Global Assessment of Functioning (GAF), Clinical Global Impression Scale - Severity (CGI-S).

Participants in the exercise group showed better depression and functional parameters at the end of the study, both compared to the beginning of the study and compared to the control group (lower HAMD17, BDI and CGI-S and higher GAF, p < 0.05).

Results suggest that exercise could be an effective adjuvant therapy for non-remitted MDD patients.