Depression is a real illness that impacts the brain. It’s not imaginary or “all in your head”. Depression is more than just feeling “down”. It is a serious illness caused by changes in brain chemistry. Research tells us that other factors contribute to the onset of depression, including genetics changes in hormone levels, certain medical conditions, stress, grief or difficult life circumstances. Any of these factors alone or in combination can precipitate changes in brain chemistry that lead to depression’s many symptoms.
The World Health Organization characterizes depression as one of the most disabling disorders in the world, affecting roughly one in five women and one in ten men at some point in their lifetime. It is estimated that 21% of women and 12% of men in the U.S will experience an episode of depression at some point in their lifetime.
What’s causing depression?
Although scientists agree that depression is a brain disorder, the debate continues about exact causes. Many factors may contribute to the onset of depression, including genetic characteristics, changes in hormone levels, certain medical illnesses, stress, grief, or substance abuse. Any of these factors alone or in combination can bring about the specific changes in brain chemistry that lead to the many symptoms of depression, bipolar disorder and related conditions.
Exercise and Depression
Can a few laps around the block actually solve your emotional problems? Probably not, but a regular exercise program might help. A review of studies stretching back to 1981 concluded that regular exercise can improve mood in people with mild to moderate depression. It also may play a supporting role in treating severe depression.
A study published in 2005 found that walking fast for about 35 minutes a day five times a week or 60 minutes a day three times a week had a significant influence on mild to moderate depression symptoms. Walking fast for only 15 minutes a day five times a week or doing stretching exercises three times a week did not help as much. (These exercise lengths were calculated for someone who weighs about 150 pounds. If you weigh more, longer exercise times apply, while the opposite is true if you weigh less than 150 pounds.)
How does exercise relieve depression? For many years, experts have known that exercise enhances the action of endorphins, chemicals that circulate throughout the body. Endorphins improve natural immunity and reduce the perception of pain. They may also serve to improve mood. Another theory is that exercise stimulates the neurotransmitter norepinephrine, which may directly improve mood.
Ednorphins act as an analgesic, which means they diminish perception of pain. They also act as sedatives. They’re manufactured in your brain, spinal cords, and many other parts of your body released in response to brain, chemicals called neurotransmitters.
Besides lifting your mood, regular exercise offers other health benefits, such as lowering blood pressure, protecting against heart disease and cancer, and boosting self-esteem. How often or intensely you need to exercise to alleviate depression is not clear, but for general health, experts advise getting half an hour to an hour of moderate exercise, such as brisk walking, on all or most days of the week.