Studies of clobazam and car-driving

1 The methodology used in studies to assess the effects of drugs on car-driving performance is reviewed. 2 Clobazam 20 mg, diazepam 10 mg or placebo were administered daily for 3 d to 24-male students with a high neuroticism score (on the Cattell Personality Factors Questionnaire). 3 Car driving performance was assessed on the second day in real traffic conditions; tests of attention and concentration and subjective assessments were made on the third day. 4 Diazepam 10 mg significantly impaired braking reaction time in comparison with clobazam 20 mg and placebo (P less than 0.01). Subjects also reported feeling more 'depressed' and lethargic after diazepam.