Stimulant drugs are commonly abused and also used to promote wakefulness, yet their effects on driving performance during sleep deprivation have been poorly studied in experimental studies. We aimed to assess the effects on fundamental driving parameters during simulated driving of two doses of d-amphetamine and further to assess the interaction between d-amphetamine and sleep deprivation. A double blind, placebo controlled experiment including eighteen healthy, male volunteers was conducted.

The participants felt more alert when taking a dose of d-amphetamine than when taking placebo and the effect was stronger for the higher dose. However, the data did not show any evidence that taking d-amphetamine prevented the subjects from successively becoming sleepier during the night. A significant main effect of dose was found for three out of the five primary indicators where the lower dose lead to improved driving while the results for the higher dose were less clear. Regarding sleep deprivation, a main effect was found for four of the primary indicators and three of the secondary indicators. The results showed impaired driving in all cases but one. We found no interactions between dose and sleep deprivation.

Our results suggest that impaired driving due to fatigue is not compensated by administration of d-amphetamine. The positive effects of 10 mg was not further improved or even sustained when increasing the dose to 40 mg. This might indicate that at still higher doses commonly taken by addicts, there are few or no positive effects of d-amphetamine.