THE DOPAMINE-SEROTONIN RELATIONSHIP IN CLOZAPINE RESPONSE

The effects of clozapine on the dopamine and serotonin systems may und erlie its atypical pharmacologic and clinical profile. To examine this hypothesis, we measured dopamine and serotonin plasma and cerebrospin al (CSF) metabolites and the relationship of these values to treatment response in 19 neuroleptic refractory and intolerant schizophrenic pa tients. Only a small change in the CSF and plasma homovanillic acid (H VA) and 5-hydroxyindoleacetic acid (5HIAA) levels was found. However, the pretreatment CSF HVA/5HIAA ratio and, to a lesser extent, the CSF HVA level predicted treatment response. These results suggest that the modest relationship between HVA and 5-HIAA and treatment response sup ports the involvement of both neurotransmitters in the pathophysiology of schizophrenia.