Depression is one of the leading causes of disability worldwide. That's the word from NIH's National Institute of Mental Health (NIMH), the component of the federal government that studies depression and other mental illnesses.

You probably know depression as a medical condition that primarily affects the brain. Its symptoms include a persistent sad, anxious or "empty" mood, feelings of hopelessness, pessimism and worthlessness, and a loss of interest in hobbies and activities once enjoyed. The "Symptoms of Depression" side box contains a more complete description.

But according to Dr. Husseini Manji, chief of NIMH's Laboratory of Pathophysiology, the psychological symptoms of depression are just the "tip of the iceberg." Because the brain is the body's "control center," the effects of depression spread throughout the body, often resulting in problems with sleep, appetite, energy level, motivation, memory, and concentration. Performing everyday activities can be an enormous challenge for people who are depressed.

A Devastating Illness

"Depression needs to be recognized as a devastating illness," Dr. Manji explains. "It can occur with other diseases, but it is a very real medical condition in its own right."

Research shows that depression increases the risk of death for people of all ages. For those with other illnesses such as type 2 diabetes and certain infections, depression can make their symptoms worse. Elderly people with depression may be at higher risk for Alzheimer's disease, and depression may increase their chance of being admitted into a nursing home.

No one knows better the ravages of depression than the estimated 20 million Americans of every age who suffer from depression. Although women and older people seem to have higher rates of depression, depression can strike anyone at any time. Those who have recently experienced a traumatic event, such as a divorce, job loss or sudden death of a loved one, may be at higher risk.

More Than Stressed Out

Dr. Manji emphasizes that depression is not a character flaw, a lack of willpower or a sign of emotional weakness. "You can't simply wish or will depression away," he says.

People who are "stressed out" may think that their current situation is to blame, but a prolonged case of the blues that interferes with normal functioning is usually the result of a chemical imbalance in the brain," he explains.

That's why treatment is so important - and the sooner the better. There are a variety of treatments that work, including medications and psychotherapy. NIMH researchers and others are constantly looking at new ways to treat and prevent depression.

If you think you may be depressed, seek professional help and learn ways to cope to help you feel better (see "Tips for Coping With Depression"). Don't let depression keep you down.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.