Depression

An external event often seems to initiate an episode of depression. Thus, a serious loss, chronic illness, difficult relationship, financial problem, or any unwelcome change in life patterns can trigger a depressive episode. Very often, a combination of genetic, psychological, and environmental factors is involved in the onset of a depressive disorder.

Women are twice as likely to become depressed as men. However, scientists do not know the reason for this difference. Psychological factors also contribute to a person's vulnerability to depression. Thus, persistent deprivation in infancy, physical or sexual abuse, clusters of certain personality traits all can increase the frequency and severity of depressive disorders, with or without inherited vulnerability.