Schizophrenia is a devastating illness that can impair all aspects of a patient's life. Although positive psychotic symptoms such as hallucinations and delusions are often emphasized, the negative symptoms of the disease prevent patients from functioning in society and limit their ability to hold a job, attend school, or form friendships. Since schizophrenia is most likely to develop between ages 15 and 25 years, its effects are felt throughout a person's life. Much research has been conducted on the etiology of the disorder, but no single cause has been identified. Most likely, it is the result of a combination of genetic, environmental, and neuropathologic factors. The costs of schizophrenia are high. These patients occupy about 25% of hospital beds. They are paid approximately 10% of Social Security benefit days, as they are often too ill to work. Given the high costs of hospital care, any pharmacologic or psychosocial therapy that can prevent hospitalization will play an important role in the treatment of these patients.