Exercise Decreases Depression --> Why?
I recently attended the American College of Sports Medicine conference and viewed an excellent symposium on exercise and mental health. Further, Gabriel and I have just completed a manuscrip that we will submit on mechanisms associated with exercise which lower depression.
In short, the evidence is very clear that exercise decreases depression. For example. Dr. McCullagh, who Gabriel is working on a number of studies for publication as we speak conducted a meta analysis in which those who exercised had moderately lower depression than those who did not. In clinical populations, Landers found that exercise had a large effect on lowering depression, and that these effects increased to very large the greater the duration of exercise was. I.E. greater than 9 weeks of exercise compared to 8 weeks or less.
Perhaps most exciting is that exercise lowers depression as much as drugs( the evidence is very strong here), and in cases more than drugs! Further, the side effects of exercise are health, a better body etc. Where as the negative effects of drugs are too many to list.
Here is the research question fellow academics and scientists. Why is this occuring? Why do you feel exercise lowers depression?
Note that depression in its greatest form can described as an affective (eg. mood) disorder characterized by psychological (mental), behavioral (our everyday behaviors or action), and physiological symptoms (actual structural or physiological changes in the body, such as changes in hormone levels) (Cryan et al., 2002). A number of the more prevalent symptoms include depressed mood, irritability, low self esteem, fatigue, and recurrent thoughts of death and suicide (Bear, Connors, and Paradiso, 2006).
thanks for your valuable input!