Schizophrenia is a mental illness that is among the world's top ten causes of long-term disability. The symptoms of schizophrenia include psychosis, apathy and withdrawal, and cognitive impairment, which lead to problems in social and occupational functioning, and self-care. About 1% of the population is affected by schizophrenia, with similar rates across different countries, cultural groups, and sexes. The illness tends to develop between the ages of 16 and 30 years, and mostly persists throughout the patient's lifetime. The cause of schizophrenia is unknown, but evidence suggests that genetic factors, early environmental influences (eg, obstetric complications), and social factors (eg, poverty) contribute. No biological alterations are pathognomonic of schizophrenia, although several pathophysiological differences exist in a wide range of brain structures. Antipsychotic medications are the mainstay for managing schizophrenia. A range of psychosocial treatments are also helpful, including family intervention, supported employment, cognitive-behaviour therapy for psychosis, social skills training, teaching illness self-management skills, assertive community treatment, and integrated treatment for co-occurring substance misuse.