Cyclic AMP and GMP in the cerebrospinal fluid after high-dose haloperidol treatment.

Very high dose haloperidol treatment failed to reduce cyclic AMP in cerebrospinal fluid of schizophrenic patients, whereas phenothiazines have been reported to do so. This may represent in vivo evidence for the distinction between neuroleptics that block D1 receptors (adenylate cyclase linked) and neuroleptics that do not.