• Aggression;
  • Alcohol;
  • Paroxetine;
  • Serotonin;
  • Impulsivity

Background:  The purpose of this study was to examine the role of the serotonin (5-HT) system in alcohol-related aggression.

Methods:  Specifically, we experimentally examined the effects of 5-HT augmentation on alcohol-related aggression in men (= 56). After consuming either alcohol (mean blood alcohol concentration of 0.10%) or a placebo (no alcohol) drink, and taking either 20 mg of paroxetine (Paxil®) or a placebo pill, participants were provided the opportunity to administer electric shock to a (faux) opponent during a task disguised as a reaction-time game. Aggression was defined as the intensity of shock chosen and the frequency with which an extreme (clearly painful) shock was chosen. We predicted that 5-HT augmentation would be associated with lower aggressive behavior overall, and also reduce the aggression facilitating effects of acute alcohol intoxication.

Results:  The results indicated that alcohol intoxication increased aggression, particularly under low provocation. Paroxetine decreased aggression, particularly during high provocation. These effects, however, occurred independently of each other.

Conclusions:  The effect of alcohol on extreme aggression was moderated by previous aggression history, with more aggressive individuals showing greater alcohol-related increases in extreme aggression.