Most people with dysthymia can't tell for sure when they first became depressed. Symptoms of dysthymic disorder include a poor appetite or overeating, difficulty sleeping or sleeping too much, low energy, fatigue and feelings of hopelessness. But people with dysthymic disorder may have periods of normal mood that last up to 2 months. Family members and friends may not even know that their loved one is depressed. Even though this type of depression is mild, it may make it difficult for a person to function at home, school or work.
Dysthymia can begin in childhood or in adulthood.
Like most types of depression, it appears to be more common in women. No one knows why depression is more common in women. Dysthymic disorder is a fairly common type of depression. No one knows for sure what causes dysthymia. There may be some changes in the brain that involve a chemical called serotonin.