The (cost-)effectiveness of exercise therapy adjunct to guideline-concordant care for depression: a pragmatic randomised controlled trial.

BACKGROUND

Many patients with major depressive disorder (MDD) do not respond sufficiently to first-line treatments. Due to its biological and psychological mechanisms, exercise may enhance the effectiveness of other MDD treatments. In a pragmatic randomised superiority trial, we evaluated the clinical and cost-effectiveness of exercise therapy adjunct to guideline-concordant care as usual (CAU) for MDD in specialised mental health care.

METHODS

MDD outpatients (N = 112; Mage = 37; 51% female) were randomized to CAU (96.9% psychotherapy, 59% pharmacotherapy) or CAU + EX (CAU plus 12 weeks of exercise therapy: one supervised and two home-based aerobic sessions/week). Depressive symptoms were assessed using the Inventory of Depressive Symptomatology-Self Report. Remission was evaluated during follow-up by blinded assessors using the Structured Clinical Interview for DSM-5. The economic evaluation followed a societal perspective.

RESULTS

Patients in the CAU + EX condition were significantly more likely than those in CAU to meet the exercise prescription; however, only 22% fully adhered to it. Depressive symptoms decreased from severe to moderate depression in both conditions, with no significant difference between the conditions on symptom reduction (b = -0.22, [-0.72, 0.29]) or remission rate (OR = 0.06, [-0.20, 0.32]). Evidence for cost-effectiveness was found in the per-protocol (≥ six supervised exercise sessions) but not in the intention-to-treat sample.

CONCLUSIONS

Adjunct exercise therapy does not provide additional clinical benefits or cost-effectiveness in specialized mental health care. Low adherence to the exercise prescription limits its potential. Cost-effectiveness may be achievable with higher adherence, warranting emphasis on strategies to improve adherence in this population.