Schizophrenia Schizophrenia Schizophrenia is a mental disorder characterized by loss of contact with reality (psychosis), hallucinations (usually, hearing voices), firmly held false beliefs (delusions), abnormal thinking... read more and related psychotic disorders—brief psychotic disorder Brief Psychotic Disorder The symptoms of brief psychotic disorder resemble the delusions, hallucinations, or other psychotic symptoms of schizophrenia, but they last for a much shorter time (from 1 day to 1 month).No... read more , delusional disorder Delusional Disorder Delusional disorder is characterized by one or more firmly held false beliefs that persist for at least 1 month. The false beliefs may be ordinary things that could occur (such as being deceived... read more , schizoaffective disorder Schizoaffective Disorder Schizoaffective disorder is characterized by the presence of mood symptoms, such as depression or mania, plus the psychotic symptoms of schizophrenia. Psychosis refers to symptoms such as delusions... read more , schizophreniform disorder Schizophreniform Disorder Schizophreniform disorder causes symptoms of schizophrenia, but the symptoms last only 1 to 6 months. As in schizophrenia, people with schizophreniform disorder have symptoms such as delusions... read more , and schizotypal personality disorder Schizotypal Personality Disorder Schizotypal personality disorder is characterized by a pervasive pattern of intense discomfort with and reduced capacity for close relationships, by distorted ways of thinking and perceiving... read more —are characterized by psychotic symptoms, and often by negative symptoms and cognitive dysfunction.
Psychotic symptoms include delusions, hallucinations, disorganized thinking and speech, and bizarre and inappropriate motor behavior (including catatonia).
Negative symptoms are a decrease in or lack of normal emotions and behaviors. For example, people may lack motivation and their face may not express emotions.
Cognitive dysfunction refers to problems with thinking (cognition), such as being able to focus one's attention, remember things, have self-control, and think flexibly.
Diagnosis and treatment of schizophrenia and related psychotic disorders are based on symptoms and the course of the specific illness.