RESUMO
Exercise can be an effective treatment for depression. Although the efficacy of exercise is well established, little is known concerning the biological changes associated with the antidepressant effects of exercise. A randomized, controlled trial was conducted to evaluate the effects of adding exercise to the usual treatment on the thiobarbituric acid-reactive substances (TBARS) and brain-derived neurotrophic factor (BDNF) serum levels of severely depressed inpatients. Twenty-six participants were randomized to an exercise group (n=15, exercise+treatment as usual) or a control group (n=11, treatment as usual). The participants in the exercise group completed a targeted dose of 16.5 kcal/kg/week of aerobic exercise, three times per week, throughout their hospitalizations. The control group did not exercise during their hospitalizations. The mean hospitalization length was of 21.63 (4.5)×23.82 (5.7) days for exercise and control groups, respectively. The exercise group performed a median of nine sessions. After adjusting for previous tobacco use, a significant group×time interaction was found for TBARS serum levels (p=0.02). A post hoc Bonferroni test revealed differences between the exercise and control groups at discharge. A significant time effect (p<0.001) but no group×time interaction was found (p=0.13) for BDNF serum levels. Adding exercise to the usual treatment of severely depressed inpatients decreases the TBARS serum levels of severely depressed inpatients after 3 weeks. Adding exercise had no additional effects on BDNF serum levels.
