Meta-analysis of 15 studies on depression suggests significant mental health benefits from being physically active

Is exercise really that important for an individual’s mental health? A new study published in JAMA Psychiatry suggests that exercise is linked to lower levels of depression, even for people who engage in less physical activity than recommended by public health professionals.

Depression is a common and often debilitating mental illness that can lead to a wide range of negative outcomes, including isolation and even suicide. There are many factors that can influence the development of an individual depression. Additionally, there are many different interventions that have been shown to be effective in treating or preventing depression. There has been previous research suggesting that physical activity may be a preventative measure for depressive symptoms.

Matthew Pearce and colleagues conducted a meta-analysis to study the association between physical exercise and depression. The samples used were adults who reported an element of physical activity and risk factors for depression. Studies were extracted from multiple online sources. Data were extracted from the studies, including volume of physical activity, cases of depression, number of participants, and follow-up.

This study used 348 full-text articles and their data. The countries included the United States, Australia, Japan, India, Ghana, Mexico and Russia. The results showed that the greatest benefits on participants’ depression occurred when they went from no physical activity to some physical activity, rather than from little exercise to high levels of exercise. Just 2.5 hours a week of brisk walking was linked to a 25% lower risk of depression.

This relationship is thought to be due to a few different mechanisms, including inflammatory responses to activity and long-term changes in the brain. Additionally, it has been suggested that it may be related to self-esteem and body image, which can help with social interactions and coping skills.

Despite the benefits of this study, it also has its limitations. While meta-analysis is a great way to collect a large amount of data from a variety of sources, the measures were somewhat different for many of the studies, including type or level of physical activity and follow-up time. This makes the study lack some consistency. Furthermore, this research could not rule out the possibility that depression affects physical activity, and not vice versa.

However, the results indicate that there is an important link between physical activity and the reduction of depression.

“This meta-analysis found an association between physical activity and incident depression,” the authors concluded. “This suggests that substantial mental health benefits can be achieved at physical activity levels even below public health recommendations, with additional benefit in reaching the minimum recommended goal, but limited additional benefit beyond that. Assuming causality, 1 in 9 cases of depression could have been prevented if everyone in the population was active at the level of current health recommendations.”

The study, “Association between physical activity and risk of depression“, was written by Matthew Pearce, Leandro García, Ali Abbas, Tessa Strain, Felipe Barreto Schuch, Rajna Golubic, Paul Kelly, Saad Khan, Mrudula Utukuri, Yvonne Laird, Alexander Mok, Andrea Smith, Marko Tainio, Søren Brage and James Becada .