Depression has a habit of attaching itself to lots of health problems, not just for the patient, but also sometimes for carers and other family members.

This systematic review and meta-analysis looks at the association between activity restriction and depression in medical patients and their caregivers.

The review found a clear positive relationship between lack of activity and depression, which unsurprisingly was most significant for depressed patients:

• depression in medical patients (r=0.45; 95% CI, 0.42-0.48)
• depression in caregivers (r=0.34; 95% CI, 0.28-0.41)
• depression in community-dwelling adults (r=0.28; 95% CI, 0.25-0.31)

Note: Effect sizes were calculated as Pearson r correlations using random-effects models (See the Wikipedia entry for an explanation of the stats).

The reviewers from the University of California conclude that:

Assessment and treatment of activity restriction may be particularly helpful in preventing depression.

Mausbach BT, Chattillion EA, Moore RC, Roepke SK, Depp CA, Roesch S. Activity restriction and depression in medical patients and their caregivers: A meta-analysis. Clin Psychol Rev. 2011 Apr 28;31(6):900-908. [PubMed abstract]