Depression is a serious medical condition. In contrast to the normal emotional experiences of sadness, loss, or passing mood states, clinical depression is persistent and can interfere significantly with an individual's ability to function. Symptoms and Types of Depression Symptoms of depression include sad mood, loss of interest or pleasure in activities that were once enjoyed, change in appetite or weight, difficulty sleeping or oversleeping, physical slowing or agitation, energy loss, feelings of worthlessness or inappropriate guilt, difficulty thinking or concentrating, and recurrent thoughts of death or suicide. A diagnosis of major depressive disorder is made if a person has 5 or more of these symptoms and impairment in usual functioning nearly every day during the same two-week period. Major depression often begins between ages 15 to 30 but also can appear in children.
Episodes typically recur.
Many people with dysthymia develop major depressive episodes. Episodes of depression also occur in people with bipolar disorder. Because bipolar disorder requires different treatment than major depressive disorder or dysthymia, obtaining an accurate diagnosis is extremely important. Facts About Depression Major depression is the leading cause of disability in the U.S. and worldwide. Depressive disorders affect an estimated 9.5 percent of adult Americans ages 18 and over in a given year, or about 18.8 million people in 1998.