ABSTRACT
Psychosis is an impaired ability to perceive reality (impaired reality testing), which may result in delusions and hallucinations, among other symptoms. According to the DSM-IV (American Psychiatric Association, 1994), there are nine major categories of psychotic disorders:
Schizophrenia: a disorder lasting at least 6 months, including two or more of the following: delusions, hallucinations, disorganized speech, severely disorganized or catatonic behavior, negative symptoms. The general category of schizophrenia includes the specific subtypes: paranoid, disorganized, catatonic, undifferentiated, and residual.
Schizophreniform Disorder: a disorder with symptoms similar to schizophrenia lasting less than 6 months and excluding a general reduction in functioning.
Schizoaffective Disorder: a disorder characterized by symptoms of schizophrenia (e.g., delusions, hallucinations, negative symptoms, disorganized speech, severely disorganized or catatonic behavior) and an episode of disordered mood, preceded or followed by at least 2 weeks of delusions or hallucinations without affective symptoms.
Delusional Disorder: a disorder in which ‘nonbizarre’ delusions occur for at least 1 month, but without other schizophrenic symptoms.
Brief Psychotic Disorder: a psychotic disorder lasting more than 1 day but that subsides within 1 month.
Shared Psychotic Disorder: a disorder that develops as a result of contact with another individual who suffers from a delusion similar in nature.
Psychotic Disorder Due to a General Medical Condition: a disorder in which the psychotic symptoms are a result of a general medical condition. Medical illnesses which can result in psychotic symptoms include CNS tumors, brain trauma as a result of head injury, dementias such as Alzheimer’s disease, Huntington’s disease (an hereditary disease characterized by involuntary repetitive, rapid, and jerky movements and mental deterioration), multiple sclerosis, and epilepsy.
Substance-Induced Psychotic Disorder: a disorder in which the psychotic symptoms are a result of drug abuse, a prescribed medication, or a toxin. Drugs that can cause psychotic symptoms include cocaine, steroids, anti-Parkinsonian drugs, psychedelics, and hallucinogens such as LSD and PCP.
Psychotic Disorder not Otherwise Specified: a psychotic disorder that does not fulfill the criteria for any of the previous psychotic disorders.
