Exercise Helps Residual Depression
Many patients with depression require two or more treatments in order to achieve remission. In a 2011 study by Trivedi et al. published in the Journal of Clinical Psychiatry, patients with major depressive disorder who had not responded adequately to selective serotonin reuptake inhibitor (SSRI) antidepressants improved when an exercise regimen was added to their regular treatment.
The patients, aged 18-70 years old, were all sedentary at the start of the trial. They were randomized to one of two exercise regimens: a high dose regimen (16 kcal/kg per week, equivalent to walking at about 4 mph for 210 minutes per week) or the low dose (4 kcal/kg per week, equivalent to walking at 3 mph for about 75 minutes per week). Both groups improved significantly by the end of the study. Remission rates (adjusted for differences between groups) were 28.3% for the high dose group and 15.5% for the low dose group.
The rates of improvement with exercise were similar or better to those commonly seen with other augmenting agents such as lithium, T3, buspirone, and atypical antipsychotics, but without side effects and other inconveniences such as blood monitoring.
Other studies have indicated that exercise by itself and in combination with other treatments has efficacy in depression. Exercise can change serotonin and norepinephrine function and can increase brain-derived neurotrophic factor (BDNF), a, and neurogenesis in the hippocampus.
The researchers looked for moderating variables that may have affected the outcomes of various participants. Men, regardless of family history of mental illness, had better remission rates in the high dose group. Women without a family history of mental illness also improved more in the high dose group, while women with a family history of mental illness improved more in the low dose group, though this finding was statistically nonsignificant.
While the researchers observed that those in the high-dose group did exercise more than those in the low-dose group, participants in the high-dose group had more difficulty sticking to their exercise regimen. It may be that even though high doses of exercise offer slightly higher rates of remission, lower doses may be more effective clinically if patients can stick to the low-dose regimen better.
