While not as crippling as a major depression, the persistent hold of dysthymia (dis-THIGH-me-ah) can keep you from feeling good and can intrude upon your work, school, and social life. The contrast between the two illnesses might be likened to a dim gray color versus black. Unlike a major depression, in which relatively limited episodes may be separated by considerable spans of time, dysthymia lasts for an average of at least five years.

If you suffer from dysthymia, more often than not you feel depressed during most of the day, and this situation will persist over at least two years. You may be able to carry out daily responsibilities, but much of the zest is gone from your life. Your depressed mood does not lift for more than two months at a time and is also marked by at least two of the following symptoms:

• Overeating or a loss of appetite
• Insomnia or sleeping too much
• Little energy or feeling tired
• Low self-esteem
• Trouble concentrating or making decisions
• Hopelessness

Sometimes an episode of major depression occurs on top of dysthymia. When this happens, it's known as a double depression.

Dysthymia often begins in childhood, the teen years, or early adulthood. Being drawn into this low-level depression early -- that is, before age 21 -- appears to put you at higher risk for major depression. In fact, up to 75 percent of people who are diagnosed with dysthymia will have an episode of major depression within five years.

Untreated dysthymia has a dismal rate of remission. Only about 10 percent of people spontaneously emerge from it in a given year. Some appear to get beyond it for as long as two months, only to spiral downward again. However, proper treatment eases dysthymia and other depressive disorders in about four out of five people.

From the Harvard Health Publications Special Health Report, Depression Report. Copyright 2002 by President and Fellows of Harvard College. All rights reserved.