Forty-eight healthy volunteers aged between 18 and 61 years, 24 men, 24 women, received dosulepin (Idom) or placebo in a randomized fashion over a period of 16 days. The study was designed as a double-blind, placebo controlled parallel trial. The single daily dose of 75 mg was given in the evening. In order to assess driving ability under medication, the following parameters were examined before the study and on days 3, 10 and 17: visual orientation, concentration stress toleration while performing reaction tasks, eye-hand coordination, vigilance, accuracy and speed of reaction, and sense of wellbeing. Apart from a mild loss of concentration and decrease in the sense of wellbeing, none of the other parameters showed any significant changes as compared with placebo. The results are in good agreement with those of earlier relevant trials with other antidepressants. The results of the present study form the basis for an assessment of the driving ability of the individual patient receiving dosulepin.