Psychotic disorders are severe mental disorders that cause abnormal thinking and perceptions. People with psychoses lose touch with reality. Two of the main symptoms are delusions and hallucinations. Delusions are false beliefs, such as thinking that someone is plotting against you or that the TV is sending you secret messages. Hallucinations are false perceptions, such as hearing, seeing, or feeling something that is not there.
Schizophrenia is one type of psychotic disorder. People with bipolar disorder may also have psychotic symptoms. Other problems that can cause psychosis include alcohol and some drugs, brain tumors, brain infections, and stroke.
Treatment depends on the cause of the psychosis. It might involve drugs to control symptoms and talk therapy. Hospitalization is an option for serious cases where a person might be dangerous to himself or others.
Source: National Institutes of Health, MedlinePlus