Etiopathogenesis and treatment of psychosis.

Psychotic illnesses (schizophrenia and schizoaffective and affective psychosis) have a lifetime prevalence of 2-3% and probably occur at a similar rate in all human societies. No etiologically significant environmental precipitants have been identified, and this suggests that these diseases are primarily genetic. Brain studies reveal that in schizophrenic patients, development of cerebral asymmetry is arrested, which may be associated with a small reduction in cortical mass. Episodes of illness can be ameliorated by dopamine (in particular D2) antagonists, drugs that are antipsychotic rather than merely antischizophrenic. The discovery of at least five dopamine receptor subtypes and their genes paves the way for new approaches to treatment. However, whether psychotic patients undergo a primary disturbance of dopaminergic transmission remains unclear.