Effects of alcohol on cardiovascular reactivity and the mediation of aggressive behaviour in adult men and women.

AIMS Recent models have proposed several pharmacological means by which alcohol may produce heightened aggression, among them that alcohol may both hyper-arouse the reward system and diminish the threat detection system. The current study examined these hypotheses employing heart rate and blood pressure as physiological indices of arousal, examining whether arousal differed by alcohol group, and if this related to level of aggression. METHODS Participants were 32 males and 32 females, aged 18-30 years, screened for physical and psychological disorder, who competed on the Taylor aggression paradigm. The gender groups were further split into half sober, half intoxicated. Arousal was measured at baseline, post-beverage consumption, and post-aggression paradigm. RESULTS Participants in the alcohol condition initially demonstrated slight heart rate elevations and blood pressure decreases, but showed little arousal in response to the aggression paradigm, whereas sober participants demonstrated considerable arousal on both indices. Intoxicated participants were more aggressive than sober controls; men and women did not differ significantly. Regression analyses demonstrated that change in systolic blood pressure from post-beverage consumption to post-aggression paradigm acts as a mediating variable in the alcohol-aggression relationship. CONCLUSIONS These results lend support to the stress-response dampening model of the alcohol-aggression relationship, and moreover suggest that the magnitude of intoxicated aggression is related to the magnitude of that dampening.