We have heard the speculation, but now we have the evidence: exercise can avert depression.
A recent issue of the American Psychiatric Association's Psychiatric News (Volume 44, Number 1) includes an article: "Link Grows Stronger That Exercise Can Avert Depression; Exercise seems to be capable of preventing depression in both men and women. But when it comes to high- intensity exercise, men seem to benefit more"
The article is authored by Joan Arehart-Treichel.
The study, ,which utilized a large number of subjects and a prospective design, has also linked exercise with less depression, stating, "Improving one's fitness can not only lower many disease risks such as cardiovascular disease and certain types of cancer,... but also benefit one's mental well-being," she asserted.
The study, which started in 1970, involved more than 14,000 men and women enrolled in the Aerobics Center Longitudinal Study in Dallas.
Their cardio-respiratory fitness was measured at the start of the study with a maximum treadmill exercise test. They were evaluated for depression one or two times during the follow-up period, which ranged from one to 15 years, with the average being 12 years. At the end of that time, 1,022 subjects reported having had depressive symptoms at the time of either or both assessments.
The researchers found that subjects who had been more fit at the start of the study were significantly less likely to experience depression during the follow-up period than were subjects who had been less fit at that time. Further, the results held even when a number of possibly confounding factors--baseline physical examination year, depression survey year, smoking status, alcohol consumption, body mass index, high blood pressure, and diabetes--were considered.
And perhaps most strikingly, there appeared to be a dose-response relationship between fitness and the prevention of depression. Indeed, the lead researcher and her colleagues found that obese subjects had a significantly higher risk of depressive symptoms than non-obese subjects, and in a previous study, that overweight or obese postmenopausal women could improve their physical fitness with as little as 72 minutes of moderately intense physical exercise a week.
This is an important link of which to be aware as we treat mood disorders and unhealthy eating behaviors, particularly when obesity is a presenting issue.
An abstract of the original study "Prospective Study of Cardiorespiratory Fitness and Depressive Symptoms in Women and Men" can be accessed at <www.sciencedirect.com> by clicking on "J" under "Browse by Title," then "Journal of Psychiatric Research," then "Articles in Press."