Sedentary behaviour and depression

Depressive symptoms are known to adversely influence longevity and wellbeing. In particular, depression is independently associated with cardiovascular disease and all-cause mortality, and is often co-morbid with chronic diseases that can worsen their associated health outcomes. Several decades of evidence suggests that regular participation in exercise/physical activity promotes positive mood state, has anti-depressive effects, and can protect individuals from developing depression. More recently researchers have turned their attention to effects of sedentary behaviors on mental health. Sedentary leisure pursuits, such as viewing television, films, playing video games, etc, are generally perceived to be enjoyable and relaxing. It is therefore somewhat of a paradox that emerging data suggest sedentary behavior may be a risk factor for depression independently from physical activity. In this overview we examine epidemiological evidence for an association between sedentary behavior and depressive symptoms and discuss biologically plausible mechanisms. In summary, the area of sedentary behavior and mental health is an emerging area, and data should be interpreted in light of several limitations including the use of poor exposure measures, potential for residual confounding, and lack of gold standard experimental data.