Effects of d-amphetamine on human aggressive responding maintained by avoidance of provocation

Area of Science:

• Psychopharmacology
• Behavioral Science
• Neuroscience

Background:

• Understanding the behavioral effects of psychostimulants like d-amphetamine is crucial.
• Previous research has explored amphetamine's impact on aggression, but findings can be context-dependent.

Purpose of the Study:

• To investigate the dose-dependent effects of d-amphetamine on both aggressive and nonaggressive behaviors.
• To examine how specific experimental contingencies influence d-amphetamine's impact on aggressive responding.

Main Methods:

• Male subjects received placebo or d-amphetamine (5, 10, 20 mg/70kg) in a double-blind laboratory setting.
• Behavioral responses included nonaggressive button presses for points (money) and aggressive button presses to subtract points from a fictitious opponent.
• Aggressive responding was maintained by an avoidance contingency involving scheduled provoking point subtractions.

Main Results:

• d-Amphetamine significantly increased nonaggressive responding across doses.
• Aggressive responding initially increased at the 10 mg dose but significantly decreased at the 20 mg dose compared to the 10 mg dose.
• The experimental design, specifically the avoidance contingency for aggression, influenced d-amphetamine's effects.

Conclusions:

• d-Amphetamine exhibits dose-dependent effects on aggressive behavior, with higher doses potentially reducing aggression under specific conditions.
• The relationship between aggressive responses and their consequences (provocation) can modulate the behavioral effects of d-amphetamine.
• These findings highlight the importance of experimental context in psychopharmacological research on aggression.