Depression in adults is not improved by the addition of individual exercise therapy to standard care, a pragmatic randomised controlled trial from the UK has found.

A total of 361 primary care patients aged 18-69 years, who met the ICD-10 criteria for depression and had a Beck Depression Inventory (BDI) score ≥ 14, were studied. They were randomised to usual care or usual care plus a facilitated physical activity intervention.

The intervention consisted of up to three face-to-face and ten telephone contacts with a facilitator over a period of eight months. Participants were free to choose the type of physical activity, and were encouraged to undertake moderate or vigorous exercise for 2.5 hours a week.

The intervention achieved a significant sustained increase in reported physical activity, adjusted odds ratio (OR) 2.27 (95% CI: 1.32-3.89). At 12 months follow-up, 58% of the intervention group but only 40% of the control group met the government target of 2.5 hours of moderate or vigorous exercise per week (an absolute difference of 18%).

However, this increase in physical activity did not translate into an improvement in mood. At four months follow-up, the mean BDI score for the intervention group was only half a point less than the mean score for the control group (adjusted between group difference – 0.54 (95% CI: –3.06 to 1.99). Likewise, there was no significant difference between the intervention and control groups at eight and 12 months follow-up, nor was there a significant difference in antidepressant use, adjusted OR 0.63 (95% CI: 0.19-2.06).

At baseline, 89% of the sample had mild to moderate depression. NICE recommends that patients with mild to moderate depression should receive a low-intensity psychological intervention, either guided self-help, computerised CBT or a structured group physical activity programme.1

A Cochrane review found that exercise improved depressive symptoms, but there was only a moderate, nonsignificant effect when methodologically flawed trials were excluded from the analysis.2 A recent systematic review found that depressed patients derived only a short-term benefit from exercise.3

The present trial casts further doubt on the value of exercise therapy for depressed patients. However, there are two caveats. NICE recommends group exercise therapy whereas this was a trial of individual exercise therapy. We cannot conclude from the fact that adjunctive exercise therapy is of no benefit that exercise therapy by itself is ineffective.

Moreover, exercise has significant physical health benefits, particularly for depressed patients with chronic conditions. There is evidence to suggest that inactivity is the principal mediator of the increased cardiovascular risk in depressed coronary heart disease patients,4 and inactivity is thought to be partly responsible for the increased risk of diabetes in depressed patients.5

For patients with subthreshold symptoms or mild to moderate depression of less than eight weeks’ duration, I think we should offer a choice between low-intensity interventions and watchful waiting.

We can make a case for a prescription for exercise on account of its physical health benefits, particularly for patients with chronic physical health problems, but there is no good evidence to suggest that it is an effective treatment for depression. There is no justification for prescribing exercise as an adjunct to antidepressant treatment.

Dr Phillip Bland