Central dopaminergic mechanisms in schizophrenia.

A neurochemical evaluation of the dopamine hypothesis of schizophrenia has been carried out. There was no evidence to suggest that the synthesis or inactivation of dopamine was abnormal in schizophrenia. The brain concentrations of the amine itself, its metabolities and the activities of its related enzymes were similar in controls and schizophrenics. However in vitro and in vivo evidence is presented that suggests that the illness may be associated with an increase in the numbers of dopamine D2 receptors in the brain.