Objective To evaluate the efficacy of a home-based exercise programme added to usual medical care for the treatment of depression.

Design Prospective, two group parallel, randomised controlled study.

Setting Community-based.

Patients 200 adults aged 50 years or older deemed to be currently suffering from a clinical depressive illness and under the care of a general practitioner.

Interventions Participants were randomly allocated to either usual medical care alone (control) or usual medical care plus physical activity (intervention). The intervention consisted of a 12-week home-based programme to promote physical activity at a level that meets recently published guidelines for exercise in people aged 65 years or over.

Main outcome measurements Severity of depression was measured with the structured interview guide for the Montgomery-Asberg Depression Rating Scale (SIGMA), and depression status was assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I).

Results Remission of depressive illness was similar in both the usual care (59%) and exercise groups (63%; OR = 1.18, 95% CI 0.61 to 2.30) at the end of the 12-week intervention, and again at the 52-week follow-up (67% vs 68%) (OR=1.07, 95% CI 0.56 to 2.02). There was no change in objective measures of fitness over the 12-week intervention among the exercise group.

Conclusions This home-based physical activity intervention failed to enhance fitness and did not ameliorate depressive symptoms in older adults, possibly due to a lack of ongoing supervision to ensure compliance and optimal engagement.