title: Aggressive responding in abstinent heroin addicts: neuroendocrine and personality correlates.
abstract: Objective measures of experimentally induced aggressiveness were evaluated in 20 abstinent heroin-dependent subjects, in comparison with 20 normal healthy male subjects. All the subjects were preliminarily submitted to DSM-IV interviews, Buss-Durkee Hostility Inventory (BDHI) and Minnesota Multiphasic Personality Inventory (MMPI II). During a laboratory task, the Point Subtraction Aggression Paradigm (PSAP), subjects earned monetary reinforcers with repeated button presses and were provoked by the subtraction of money, which was attributed to a fictitious other participant. Subjects could respond by ostensibly subtracting money from the fictitious subject (the aggressive response). Money-earning responses were not different in drug-free heroin addicts and controls during the first two sessions and significantly lower during the third session in heroin-dependent subjects (t=2.99, P<.01). Aggressive responses were significantly higher (F=4.9, P<.01) in heroin addicted individuals, in comparison with controls. During the experimentally induced aggressiveness, plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) concentrations increased less significantly, and norepinephrine (NE) and epinephrine (EPI) levels, together with heart rate (HR), increased more significantly in abstinent heroin-dependent subjects than in healthy subjects. PSAP aggressive responses positively correlated with catecholamine changes, BDHI "direct" and "irritability" scores, MMPI "psychopathic deviate" scores in heroin-dependent subjects and controls, and with CORT responses only in healthy subjects. No correlation was found between heroin-exposure extent (substance abuse history duration) and aggressiveness levels. The present findings suggest that heroin-dependent patients have higher outward-directed aggressiveness than healthy subjects, in relation with monoamine hyperreactivity, after long-term opiate discontinuation. Aggressiveness in heroin addicts seems to be related more to the personality traits than to drug effects. The impairment of hypothalamus-pituitary-adrenal (HPA) axis in abstinent addicted individuals could be due to a long-lasting action exerted by opiates on proopiomelanocortin (POMC) or to a premorbid psychobiological condition, in association with increased sympathetic arousal.
authors.affiliation: Centro Studi Farmacotossicodipendenze, Ser. T., AUSL, Via Spalato 2, 43100 Parma, Italy. ggerra@ausl.pr.it
authors.forename: Gilberto
authors.initials: G
authors.lastname: Gerra
authors.forename: Amir
authors.initials: A
authors.lastname: Zaimovic
authors.forename: Gabriele
authors.initials: G
authors.lastname: Moi
authors.forename: Monica
authors.initials: M
authors.lastname: Bussandri
authors.forename: Cristina
authors.initials: C
authors.lastname: Bubici
authors.forename: Matteo
authors.initials: M
authors.lastname: Mossini
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
authors.forename: Francesca
authors.initials: F
authors.lastname: Brambilla
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000374:Aggression / Q000187:drug effects / Q000523:psychology*; D019540:Area Under Curve; D004837:Epinephrine / Q000097:blood; D006439:Hemodynamics / Q000502:physiology; D006556:Heroin Dependence / Q000503:physiopathology* / Q000523:psychology*; D006728:Hormones / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008950:MMPI; D008297:Male; D009483:Neuropsychological Tests; D009490:Neurosecretory Systems / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000097:blood; D010551:Personality / Q000502:physiology*; D011569:Psychiatric Status Rating Scales; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology* / Q000523:psychology*; D013694:Temperament
chemical_list: D006728:Hormones; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine