Karen Renken was just 14, but she knew something was terribly wrong. "I
was a straight-A student, and suddenly I started failing in school," says
Renken, now 45, of Long Island, N.Y.
At high school, she would go from enjoying a seemingly normal mood to
throwing a tantrum in the hallway. Her teenage response to normal requests,
such as her mother's plea to pick up after herself, was dramatic. She would,
she says, "shriek like a maniac."
Renken was sent to a psychiatrist, who prescribed an antidepressant,...