Dopamine receptor sensitivity in the hypothalamus of chronic schizophrenics after haloperidol therapy: Growth hormone and prolactin response to stimuli

(1) The present investigation deals with a study of the hypothalamic dopamine-receptor sensitivity in schizophrenics, before and after haloperidol therapy, examined by investigation of basal GH and PRL levels and responses to an l-DOPA stimulation test. (2) Ten chronic schizophrenics, 8 males and 2 females, aged 27–53 yr, with a duration of illness from 4 to 32 yr, were studied after they were off therapy for at least 10 days. (3) The l-DOPA stimulation test was done at the beginning of the study and again 3 and 6 days after withdrawal of haloperidol which had been administered in increasing doses from 5 to 10 mg a day for 30 days. l-DOPA was given orally at a dose of 500 mg plus carbidopa 100 mg. (4) Patients were tested psychologically before and after haloperidol therapy by the Asberg Psychopathological Rating Scale and typed genetically for the HLA-SD system. (5) Basal prolactin levels before and after haloperidol therapy were low. GH secretion in response to l-DOPA was normal before haloperidol therapy. (6) After treatment the patients could be divided into two groups according to the HLA types; one group showing an increased response to the stimuli as compared with the other. The data are correlated with the psychological effectiveness of the therapy.