Increased aggressive responding in male volunteers following the administration of gradually increasing doses of testosterone cypionate.

Abstract

The present study assessed the effects of supraphysiologic doses of testosterone on aggressive responding in a controlled laboratory setting. Eight male subjects received gradually increasing doses of testosterone cypionate (150 mg/week for two weeks, 300 mg/week for two weeks, and 600 mg/week for two weeks) or placebo using a double-blind, randomized, cross-over design. Subjects were tested both before and after the series of injections. During the experimental session subjects could press a button to accumulate points exchangeable for money (non-aggressive response) or press another button to subtract points from a fictitious opponent (aggressive response). Aggressive responding was instigated by subtracting points from the subject which was attributable to the fictitious opponent. Testosterone administration resulted in a significantly higher number of aggressive responding compared to placebo.