Depression, psychiatric disorder characterized by feelings of worthlessness, guilt, sadness, helplessness, and hopelessness. In contrast to normal sadness or the grief accompanying the loss of a loved one, clinical depression is persistent and severe. A variety of related symptoms, including disturbances in sleep and eating, loss of initiative, self-punishment, withdrawal and inactivity, and loss of pleasure accompany it.
Community surveys show that as many as 20 in 100 people suffer from significant depressive symptoms at any one time; some 25 percent of the population may suffer from a depression over the course of a lifetime. The disorder strikes men and women of all ages, in all segments of society, but most studies indicate that women are more often afflicted.