OBJECTIVE: To increase understanding of the potential in elderly persons for disability related to behavioral side effects of anxiolytic medications, cognitive and psychomotor effects of clinical doses of buspirone and a popular intermediate-acting benzodiazepine, alprazolam, were examined in carefully screened, healthy elderly subjects. METHOD: Sixty subjects recruited through community organizations and newspaper advertisements and screened on the basis of history, physical examination, and laboratory studies were randomly assigned to one of three drug treatment groups. After 2 days of washout placebo, subjects were given 0.25 mg t.i.d. of alprazolam, 5 mg t.i.d. of buspirone, or placebo three times a day for a total of 14 days in a double-blind design. Behavioral assessments were completed beginning 1 hour after ingestion of medication on the second washout placebo day, day 1 of the treatment period, and day 14 of the treatment period. Tests included the continuous performance test, recall memory for word lists, digit- symbol substitution, retention of pictorial stimuli over 1 hour, the Profile of Mood States, and subjective ratings of mental status. RESULTS: Buspirone did not affect reaction time, vigilance, psychomotor speed, or memory function. Alprazolam had minimal effects on vigilance, psychomotor speed, and memory on the first treatment day and had no effects after repeated doses. CONCLUSIONS: Buspirone did not produce behavioral side effects that could lead to disability, and alprazolam had minimal side effects. Because the patients were carefully screened, it is unclear whether these medications in the doses used would have more side effects in less healthy elderly patients.