Effects of diazepam (Valium) and trait anxiety on human physical aggression and emotional state.

The effects of diazepam (10 mg orally) and trait anxiety on the aggressive behavior of normal male undergraduates were studied in a competitive reaction time task paradigm which entails shock setting with an increasingly provocative "opponent." Diazepam produced an aggression-enhancing effect which was specifically shown only by the low-trait anxious group under low provocation and generally shown by all groups under conditions of higher provocation. Reductions in state anxiety following diazepam ingestion were seen most clearly in the high- and, somewhat, the moderate-trait anxious groups. In contrast, the low-trait anxious group evidenced an increase in depression but little change in anxiety. The results are consistent with reports of the ability of antianxiety drugs to disinhibit suppressed behaviors. Moreover, trait anxiety appears to mediate the effects of diazepam on both mood states and aggressive behavior.