THE META-CHLOROPHENYLPIPERAZINE CHALLENGE TEST IN COCAINE ADDICTS - HORMONAL AND PSYCHOLOGICAL RESPONSES

We report on the neuroendocrine and psychological responsivity of 31 c ocaine addicts and 14 controls to the serotonergic agonist, meta-chlor ophenylpiperazine (m-CPP) (0.5 mg/kg p.o.). Cocaine addicts were subdi vided into subjects with aggressive tendencies and other features simi lar to those found in type 2 alcoholics and subjects without these fea tures, Following m-CPP, aggressive and nonaggressive patients had a si gnificantly blunted prolactin response compared to controls, but there was no difference between the two patient subgroups. There was no dif ference between the cortisol responses of nonaggressive patients and c ontrols, but aggressive patients had a significantly blunted cortisol response compared to controls and nonaggressive patients, Both patient subgroups reported more intense ''activation-euphoria'' and ''high'' responses following m-CPP than controls. These results could indicate the existence of alterations along serotonergic pathways in cocaine ad dicts taken as a group, In addition, a subgroup of patients who could be described as type 2 cocaine addicts appear to be biologically diffe rent from healthy subjects and from other cocaine addicts as indicated by a greater cortisol blunting following m-CPP. (C) 1997 Society of B iological Psychiatry.