depression & mental illness

Schizophrenia, the most severe of the mental disorders, usually begins in late adolescence or young adulthood. A patient's first symptoms may be hallucinations, such as hearing voices that sound as real as those of friends and family. Or they may be delusions, such as believing that aliens are sending information to him via the radio or through television programs.

A century ago, people with symptoms of obsessive-compulsive disorder (OCD) were sometimes institutionalized for life or treated with frightening operations such as frontal lobotomies.