Even young kids can suffer from depression.

As recently as 20 years ago, most mental health professionals did not believe it was possible for children to experience depression. Now, although debate continues as to the exact cause, the symptoms of childhood depression are well-established. The condition can be treated by combining medication and psychotheraphy.

"Depression in young children with a biological vulnerability (i.e., having parents and/or relatives suffering from depression) can be triggered by many things--the loss of a loved one, parental divorce, a parent's remarriage, even a friend moving away," explains Anh Nga Nguyen, a child depression expert at the University of Oklahoma Health Sciences Center. "Professionals continue to debate the question of whether this depression has a biological or environmental cause. My personal impression is that it's not an either/or issue. A cumulation of stressful events will often trigger the first episode of major depression in these biologically vulnerable children."

Unlike clinically depressed adults, youngsters suffering from major depression may exhibit more crankiness and irritability than sadness. This is an important clue, Nguyen says, because these children often are labeled incorrectly as "problem kids" by teachers and parents. "Small children usually do not have the words to fully describe how they feel. In a recent study we conducted of childhood depression, more than 95% displayed their anger and depression through improper behavior at school or at home. Most of the time, a `bad' child is really a `sad child," Nguyen points out.

Other key symptoms of childhood depression include frequent crying, feelings of...