RESEARCH REPORT doi:10.1111/j.1360-0443.2006.01566.x © 2006 The Authors. Journal compilation © 2006 Society for the Study of Addiction Addiction, 101, 1614–1621 Blackwell Publishing LtdOxford, UKADDAddiction0965-2140© 2006 The Authors. Journal compilation © 2006 Society for the Study of Addiction 2006 101•••• Original Article MDMA and driving performance J. G. Ramaekers et al. Correspondence to: Jan Ramaekers, Faculty of Psychology, Department of Neurocognition, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands. E-mail: j.ramaekers@psychology.unimaas.nl Submitted 22 February 2006; initial review completed 21 April 2006; final version accepted 17 May 2006 RESEARCH REPORT Stimulant effects of 3,4- methylenedioxymethamphetamine (MDMA) 75 mg and methylphenidate 20 mg on actual driving during intoxication and withdrawal J. G. Ramaekers 1 , K. P. C. Kuypers 1 & N. Samyn 2 , Experimental Psychopharmacology Unit, Department of Neurocognition, Faculty of Psychology, Maastricht University, the Netherlands 1 and Federal Public Service Justice, National Institute of Criminalistics and Criminology (NICC), Brussels, Belgium 2 ABSTRACT Background 3,4-methylenedioxymethamphetamine (MDMA) is currently one of the most popular drugs of abuse in Europe. Its increasing use over the last decade has led to concern regarding possible adverse effects on driving. The aims of the present study were to investigate the acute effects of MDMA on actual driving performance during the intoxi- cation and withdrawal phase. Methods Eighteen recreational MDMA-users (nine males, nine females) aged 21– 39 years participated in a double-blind, placebo-controlled, three-way cross-over study. MDMA 75 mg, methylpheni- date 20 mg and placebo were administered on day 1 of treatment (intoxication phase). Driving tests were conducted between 3 and 5 hours post-drug. Subjects returned the following day for a repetition of the driving tests between 27 and 29 hours post-drug (withdrawal phase). On-the-road driving tests consisted of a road-tracking test and a car-fol- lowing test. Its main parameters were standard deviation of lateral position (SDLP), time to speed adaptation (TSA), brake reaction time (BRT) and gain. Findings MDMA and methylphenidate significantly decreased SDLP in the road- tracking tests by about 2 cm relative to placebo on day 1 (intoxication phase). In addition, MDMA intoxication decreased performance in the car-following test as indicated by a significant rise in the ‘overshoot’ of the subjects’ response to speed decelerations of the leading vehicle. Driving performance was not affected by treatments during with- drawal on day 2. Conclusion Collectively, these data indicate that MDMA is a stimulant drug that may improve cer- tain aspects of the driving task, such as road-tracking performance, but may reduce performance in other aspects of the driving task, such as accuracy of speed adaptation during car-following performance. Keywords MDMA, methylphenidate, stimulants, on-the-road driving. INTRODUCTION 3,4-methylenedioxymethamphetamine (MDMA) is cur- rently one of the most popular drugs of abuse in Europe. Its increasing use over the last decade has led to concern regarding possible short- and long-term adverse effects. Report of short-term side effects have included physiolog- ical adverse reactions such as hyperthermia, hepato- toxicity and cardiac stimulation as well as adverse psychological reactions such as agitation, blurred vision, depression, anxiety, aggression and sleep disturbances. Of even more concern are reports on neurotoxicity of MDMA in animal studies. In humans, there is growing evidence that heavy use of MDMA is associated with sleep disorders, depression, memory impairment and attention disorders that persist for prolonged periods during absti- nence. These deficits are believed to be caused by MDMA- induced neurotoxicity, as evinced by depleted serotonin in MDMA users and by dose–response relationships between MDMA exposure and severity of cognitive deficits [1–4]. Given the large extent of its use, there are relatively few reports of death associated with MDMA use [4,5]. In most cases MDMA seems to have contributed to death