A major NHS study into whether exercise can improve depression has serious methodological flaws, according to Dr David Ashton, Medical Director of Healthier Weight. The “Treating Depression with Physical Activity” study failed to show any meaningful improvements after eight months of intensive support for 362 patients with depression in general practice.
“The problem with this study” according to Dr Ashton “is that it relied on self-reported activity levels which are notoriously unreliable as a measure of exercise intensity and compliance, both of which are crucial to achieving a sustained beneficial impact on mood”.
A recent review of more than 90 research studies not only found that regular exercise significantly reduced depressive symptoms, but also that the worse the depression the more beneficial exercise appeared to be1. However, it is essential that patients met the required physical activity levels.
“Whilst the NHS study failed to show any benefit, we must be careful about drawing the wrong conclusions” says Ashton. “The scientific evidence from well conducted studies shows a clear association between increased activity patterns and improvement in depressive illness. It would be very unfortunate if evidence from a poorly constructed study was used to inform public health policy decisions and the day-to-day advice given to patients”.
1. Herring MP, Puetz TW, O'Connor PJ, Dishman RK. Effect of exercise training on depressive symptoms among patients with a chronic illness: a systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2012;172(2):101-11.