Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality. Although schizophrenia is not as common as other mental disorders, the symptoms can be very disabling.

Schizophrenia can affect people throughout the lifespan although most commonly, the incidence (rate of diagnosis) of new cases of schizophrenia increases in the teen years, reaching a peak of vulnerability between the ages of 16 and 25 years. Men and women show different patterns of susceptibility for developing schizophrenic symptoms. Males reach a single peak of vulnerability for developing schizophrenia between the ages of 18 and 25 years. In contrast, female vulnerability peaks twice; first between 25 and 30 years, and then again around 40 years of age. About 1.2% of the population develops schizophrenia during their lifetime; more than 3.2 million Americans have the illness in a given year.