DEMO-II Trial. Aerobic Exercise versus Stretching Exercise in Patients with Major Depression—A Randomised Clinical Trial

BACKGROUND The effect of referring patients from a clinical setting to a pragmatic exercise intervention for depressive symptoms, cognitive function, and metabolic variables has yet to be determined. METHODS Outpatients with major depression (DSM-IV) were allocated to supervised aerobic or stretching exercise groups during a three months period. The primary outcome was the Hamilton depression score (HAM-D(17)). Secondary outcomes were cognitive function, cardiovascular risk markers, and employment related outcomes. RESULTS 56 participants were allocated to the aerobic exercise intervention versus 59 participants to the stretching exercise group. Post intervention the mean difference between groups was -0.78 points on the HAM-D(17) (95% CI -3.2 to 1.6; P = .52). At follow-up, the participants in the aerobic exercise group had higher maximal oxygen uptake (mean difference 4.4 l/kg/min; 95% CI 1.7 to 7.0; P = .001) and visuospatial memory on Rey's Complex Figure Test (mean difference 3.2 points; 95% CI 0.9 to 5.5; P = .007) and lower blood glucose levels (mean difference 0.2 mmol/l; 95% CI 0.0 to 0.5; P = .04) and waist circumference (mean difference 2.2 cm; 95% CI 0.3 to 4.1; P = .02) compared with the stretching exercise group. CONCLUSIONS The results of this trial does not support any antidepressant effect of referring patients with major depression to a three months aerobic exercise program. Due to lower recruitment than anticipated, the trial was terminated prior to reaching the pre-defined sample size of 212 participants; therefore the results should be interpreted in that context. However, the DEMO-II trial does suggest that an exercise program for patients with depression offer positive short-term effects on maximal oxygen uptake, visuospatial memory, fasting glucose levels, and waist circumference. TRIAL REGISTRATION ClinicalTrials.gov NCT00695552.