Effects of diazepam (Valium) on a laboratory measure of self-aggressive behavior in men and women
Suicide continues to be one of the leading causes of mortality in the United States, and investigating factors associated with suicide may help guide treatment and prevention efforts. Non-experimental studies have shown that alcohol and drug use are associated with self-aggression, including suicide. Retrospective studies suggest that benzodiazepines, such as diazepam. (Valium), are the most common type of drug (other than alcohol) associated with self-aggressive behaviors and suicide. However, no published experimental studies have tested the hypothesis that diazepam facilitates self-aggressive behavior. The current study employed a laboratory paradigm called the Self-Aggression Paradigm (SAP task) to examine the effects of two dose levels of diazepam on self-aggressive behavior. Participants in this study consisted of 46 individuals (27 men and 19 women), aged 18 to 42. Participants were told they were participating in an experiment on the effects of a tranquilizer on visual-motor performance. Participants completed a series of questionnaires and interviews to assess psychopathology and variables related to self-aggressive behavior (e.g., depression, past self-aggressive behaviors). Participants were then administered either: (a) a placebo capsule, (b) 5 mg diazepam, or, (c) 10 mg diazepam using double-blind procedures. Thirty minutes after ingesting the capsule, participants engaged in a competitive reaction time task (SAP task) against a fictitious opponent in which participants determined the level of electrical shock they would receive if they were slower on a given trial. The level of self-selected shock served as a measure of self-aggression. Results indicated that the 10 mg dose of diazepam facilitated self-aggression, including the selection of shock levels twice the amount the participant believed to be highly unpleasant. Results also showed that participants who ingested 10 mg diazepam reported that the highest shock self-administered was less painful than did participants who ingested placebo. These results occurred independent of any risk factors, and suggest that diazepam use is an important variable to examine when assessing self-aggression in populations believed to be at risk for such behavior.