While depression is a chronic illness, diagnosing it can be tricky because its individual symptoms vary. Most psychiatrists agree that someone who's clinically depressed has experienced ó over a period of at least several months ó a gloomy outlook on life, a lack of pleasure in most activities, and a general feeling of worthlessness. Other symptoms range from inertia, indecisiveness, guilt, and fatigue to anxiety, irritability, and tearfulness.
A depressed person may sleep too much or too little, eat too much or too little, and gain weight or lose it. She may lose command of her vocabulary or her ability to concentrate. She may lie in bed all day or compulsively do housework. She may pick fights with a spouse or clam up entirely. Over time, if left untreated, depression not only warps a person's way of seeing herself but also alters neural functioning so that depressive behavior actually becomes biochemically ingrained.
There's little consensus on just what causes depression, although it can be precipitated by traumatic life events. It's clear, however, that for some people depression comes out of the blue, the way any serious illness can. Even those whose depression appears to have an underlying cause are probably predisposed to it either genetically or chemically. It can occur at any point during a person's life, even in childhood; for largely unknown reasons, women are particularly vulnerable soon after childbirth.
At its most virulent, depression progresses from sadness to despair to suicide. Even a mother's profound love for her child may be no match for her desire to end such relentless pain; she may believe that ending her life will spare others -- including her kids -- from the hardship of living with her.
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