Dr. Andrew Kozel is so sure of the benefits of exercise in treating depression that he writes a prescription for it, just as he would for pills.
"I spend a lot of time talking to patients about exercise," said Kozel, director of the Mood and Anxiety Disorders Program at USF Health and associate professor of psychiatry and neuroscience. "A number of studies have shown that by itself and as an augmentation to other treatment it is beneficial."
Experts are divided on why exactly exercise helps. Some hold to the theory that aerobic activity intense enough to increase the heart rate stimulates production of brain chemicals, including dopamine. These substances aid concentration and motivation, helping us to participate in activities and complete tasks.
"These are things depressed people have difficulty with," said Dr. Asher Gorelik, a psychiatrist and director of behavioral medical services for BayCare Behavioral Health.
Some researchers have found that exercise also increases a substance called brain derived neurotrophic factor, or BDNF, which stimulates the growth of new connections between nerve cells.
"That's a process we see in patients who have recovered from severe depression. There's some evidence that exercise may stimulate production of BDNF, which may help the brain repair itself," said Gorelik.
Whatever the mechanism by which it works, there's no doubt that people suffering from mild to severe depression can benefit from some physical activity most days of the week. "I don't think it will replace other treatments, but there have been several large studies that demonstrate that exercise alone and when used with antidepressant medication can be very helpful," Kozel said.
"It is an underused remedy. I'd like to see it used more commonly as a component of treatment. Energy, apathy, anxiety can all be significantly improved with exercise."
TIPS FROM THE DOCTORS
• Any physical activity is better than nothing. But ideally, it should be intense enough to elevate the heart rate and breathing at least four or five days of the week.
• Taking an exercise class or walking with friends is even better. "When someone is depressed, their natural impulse is to isolate, and that feeds depression. Taking a class or doing an activity with a friend or family member is better than doing it alone," said Gorelik.