Increased aggression and toxicity in grouped male mice treated with tranquilizing benzodiazepines

N-demethyldiazepam, diazepam and oxazepam incorporated in the diet were fed to albino Swiss male and female mice (10–50 mg per day per kg of body weight) for 6 months. Increased mortality was observed in grouped male mice but not in female or isolated male mice. Multiple skin lesions and necroses found in grouped male mice were probably due to increased aggression.