Antipsychotic drugs are medicines used to treat psychosis and other mental and emotional conditions. Psychosis is a severe mental illness in which people lose touch with reality. They may hear voices, see things that aren't really there, and have strange or untrue thoughts, such as believing that other people can hear their thoughts or are trying to harm them. They may also neglect their appearance and may stop talking or talk only "nonsense."

Antipsychotic drugs do not cure mental illness but can reduce some of the symptoms or make them milder. The medicine may improve symptoms enough for the person to undergo counseling and live a more normal life. The type of antipsychotic medicine prescribed depends on the type of mental problem the patient has. There are two main classifications of psychosis; the first is organic brain syndrome, a temporary or permanent structural dysfunction of the...