FUNCTIONAL NEUROIMAGING AND PHARMACOGENETIC STUDIES OF CLOZAPINES ACTION AT DOPAMINE-RECEPTORS

The factors that influence response to neuroleptic drugs are poorly un derstood. These factors may include clinical variables such as length of illness before treatment,1 age at onset,2.3 and the presence of neg ative symptoms4; and pharmacologic factors such as rates of drug metab olism. For example, pharmacodynamic differences in therapeutic respons e to haloperidol have been observed between Chinese and Caucasian pati ents.5 Response rates may also reflect clinical heterogeneity, althoug h familiality, history of obstetric trauma, or ventricular enlargement have been not shown to be significant factors.3 It is also possible t hat genetic differences in receptors that are targets for these drugs may influence response.