A comparison of the effects of lorazepam with those of propranolol on experimentally-induced anxiety and performance.

In a double-blind cross-over study the effects of propranolol (80 mg) and of lorazepam (1 or 2.5 mg) were assessed in normal student volunteers using a number of performance tests and mood-rating and bodily symptom questionnaires. Drug effects on experimentally-induced anxiety were also studied. The high dose of lorazepam impaired performance in digit-symbol substitution, symbol copying and verbal learning tests, and increased subjects' ratings of dizziness. Both lorazepam and propranolol increased simple reaction time. Lorazepam but not propranolol increased ratings of sedation. Although the stressor increased subjects' ratings of anxiety, neither drug altered anxiety ratings. Propranolol decreased and lorazepam increased subjects' pulse. These changes were not reflected in subjects' self-ratings - lorazepam caused a reduction in ratings of palpitations. The results suggest that if administered acutely, neither drug is beneficial in the treatment of short-term anxiety associated with intellectual stress.