Definition

Depressive disorders are mental illnesses characterized by deep, long-lasting feelings of sadness or despair. The patient may also lose interest in things that were once pleasurable. Changes in sleep patterns, appetite, and mental processes may also accompany depressive disorders. Depressive disorders are also known simply as depression or as unipolar (one-sided) depression.

Description

Everyone experiences feelings of unhappiness and sadness occasionally. In some cases, however, these feelings can begin to take over a person's everyday life. They cause a person's physical and mental health to deteriorate.

Experts estimate that depressive disorders affect seventeen million Americans. One in four women is likely to experience at least one episode of depressive disorder in her lifetime. The rate is about one in eight among men. Depressive disorders can strike all age groups, from children to the elderly. The average age a first depressive episode occurs is in the...