PERSONALITY-CORRELATES OF (+ -)-PINDOLOL INDUCED DECREASES IN PROLACTIN/

The present study was conducted to investigate if personality traits c an be usefully related to serotonergic vs. dopaminergic action of the 5-HT1a-antagonist +/- pindolol. Forty healthy male volunteers (aged be tween 20 and 30 years) were randomly assigned to a placebo or a +/- pi ndolol (30 mg, oral dose) group in a double blind trial. Blood samples were drawn and analyzed for PRL concentrations. In addition, the subj ects completed questionnaires on personality, The results indicated th at +/- pindolol decreases PRL concentrations depending on personality. While subjects high on impulsivity and related traits (aggression and disinhibition) show lower PRL decreases, well-being and personality t raits frequently related to dopaminergic activity were not correlated with changes in PRL, Since reduced (blunted) PRL-responses after 5-HT challenge tests have been reported for impulsives, the present results favor the involvement of primarily serotonergic and probably only sec ondarily dopaminergic control of +/- pindolol induced PRL decreases.