Effects of chronically administered buspirone and diazepam on driving-related skills performance.

The effects on driving skills of buspirone and diazepam, singly and in combination with alcohol, were examined. Three groups of 16 subjects each (8 men and 8 women) received either 20 mg of buspirone, 15 mg of diazepam, or placebo daily for 9 days. On day 9, they also received alcohol (men, 0.85 g/kg; women, 0.72 g/kg). On days 1, 8, and 9, subjects were tested on a driving simulator and given four sessions of divided attention tasks examining tracking and visual search performance. Extensive evidence of performance impairment associated with diazepam contrasted with improved performance under chronic buspirone treatment. Alcohol effects were additive.