Depression is an affective disorder characterized by sadness of mood, poverty of ideas, and psychomotor retardation. Depression may occur at any stage of the life. Depression is a major cause of suicide among teens. During the past three decades the rate of suicide in the age between 15-24 years has tripled and it is the third leading cause of death in this age group. The symptoms of depression in the elderly are not very different from those in younger adults. In high-income countries, the connection between suicide and mental disorders, particularly alcohol use disorders and depression, as well as a previous attempt at suicide, is well established. However, many suicides occur impulsively in times of crisis when people are unable to deal with life's stresses, such as financial issues, relationship breakups, or chronic pain and illness.