When Does Depression Begin and How Long Does It Last?

The average age of onset of major depression is in the early 20s, but depressive disorders can and often do begin in childhood or early adolescence. On the average, an episode of major depression lasts six to nine months without treatment. Dysthymia, which often precedes major depression, by definition lasts at least two years (one year in children and adolescents), and may persist even longer. Most forms of depression tend to persist over time, and each episode of depression increases the risk of future episodes. It has been estimated that 60% of those who have an episode of major depression have a second episode, 70% of those who have a second episode have a third, and 90% of those who have a third episode have a fourth. Most people experience complete remission of symptoms between episodes, but 20-30% experience only partial remission. Twenty to forty percent of those who have major depression go on to develop bipolar disorder.

What is the Impact of Depression?

Depression is a major risk factor for suicidal thoughts and behavior, and it has been estimated that 15% of people with severe major depression eventually die by suicide, which is the third leading cause of death for adolescents and young adults ages 15 to 24. Most--although not all--people who attempt or commit suicide are depressed.

In addition to this most dire outcome, the costs of depression in terms of mental, physical, and social disability are staggering. Depression impairs a person's ability to function in all important areas of daily life--school or work, family and other intimate relationships, leisure activities, etc. Results of a recent survey indicate that depression costs U.S. employers approximately $44 billion per year in lost productivity due to poor job performance and absenteeism. In 1990, mental disorders of all types cost an estimated $148 billion, which included treatment costs of $67 billion--10% of the total annual direct cost of health care in the U.S.