Depression is a serious mental illness.
In contrast to the normal emotional experiences of sadness, loss, or passing mood states, depression is persistent and can interfere significantly with an individual s ability to function. Symptoms of depression include persistent sad mood, loss 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. Major depression often begins between ages 15-30 or even earlier. Episodes typically recur. An estimated 5.3 percent of American adults ages 18 to 54 suffer from unipolar major depression in a given year.