Depression, or depressive disorders, is a leading cause of disability in the United States as well as worldwide. It affects an estimated 9.5 percent of American adults in a given year. Nearly twice as many women as men have depression. Depression is more than just being in a bad mood or feeling sad. Everyone experiences these feelings on occasion, but that does not constitute depression. Depression is actually not a single disease; there are three main types of depressive disorders. They are major depressive disorder, dysthymia, and bipolar disorder (manic-depression).
While some of the symptoms of depression are common during a passing “blue mood,” major depressive disorder is diagnosed when a person has five or more of the symptoms nearly every day during a two-week period. Symptoms of depression include a sad mood, a loss of interest in activities that one used to enjoy, a change in appetite or weight, oversleeping or difficulty sleeping, physical slowing or agitation, energy loss, feelings of worthlessness or inappropriate guilt, difficulty concentrating, and recurrent thoughts of death or suicide.
When people have depression, their lives are affected severely: they have trouble performing at work or school, and they aren’t interested in normal family and social activities. In adults, an untreated major depressive episode lasts an average of nine months. At least half of the people who experience an episode of major depression will have another episode of depression at some point.