Risky car following in abstinent users of MDMA

Abstract

Ecstasy (MDMA) use raises concerns because of its association with risky driving. We evaluated driving performance and risk taking in abstinent recreational MDMA users in a simulated car following task that required continuous attention and vigilance. Drivers were asked to follow two car lengths behind a lead vehicle (LV). Three sinusoids generated unpredictable LV velocity changes. Drivers could mitigate risk by following further behind the erratic LV. From vehicle trajectory data we performed a Fourier analysis to derive measures of coherence, gain, and delay. These measures and headway distance were compared between the different groups. All MDMA drivers met coherence criteria indicating cooperation in the car following task. They matched periodic changes in LV velocity similar to controls (abstinent THC users, abstinent alcohol users, and non-drug users), militating against worse vigilance. While all participants traveled approximately 55mph (89kph), the MDMA drivers followed 64m closer to the LV and demonstrated 1.04s shorter delays to LV velocity changes than other driver groups. The simulated car following task safely discriminated between driving behavior in abstinent MDMA users and controls. Abstinent MDMA users do not perform worse than controls, but may assume extra risk. The control theory framework used in this study revealed behaviors that might not otherwise be evident.

The effect of d,l-methamphetamine on simulated driving performance

“…Repeated driving and blood assessments may also contribute to reducing any possible variance in the peak subjective effects and metabolism of methamphetamine that may have mitigated any driving improvements or decrements apparent in the current study. Whilst methamphetamine has been reported to induce transient cognitive improvement and mood enhancement, its consumption has also been linked to deterioration in driving ability, whether through increased risktaking behaviour (Dastrup et al 2010) or cognitive disruption. This is of particular concern given the documented use of methamphetamine by professional drivers to facilitate completion of long-haul drives on time.…”

The Effects of MDMA and Methamphetamine on Car Driving Simulator Performance, Cognitive Skills, and Mood States

“…This adds to the limited empirical information on car driving skills related to Ecstasy/MDMA [3][4][5]. Less driving impairment was observed in the methamphetamine condition, this may be attributed to the stimulant effects of small doses of methamphetamine administered.…”

“…Ramaekers et al [3] reported that an acute dose of 75mg MDMA improved tracking accuracy, but impaired speed adaptation during carfollowing. Dastrup et al [4] noted that abstinent Ecstasy users were not impaired on car driving skills, but did assume extra risk. In an analysis of traffic accidents involving stimulant drugs, Verschraagen et al [4] reported more fatalities involving MDMA than amphetamine.…”

“…Dastrup et al [4] noted that abstinent Ecstasy users were not impaired on car driving skills, but did assume extra risk. In an analysis of traffic accidents involving stimulant drugs, Verschraagen et al [4] reported more fatalities involving MDMA than amphetamine. The present study was funded by an Australian Research Council Discovery Grant (DP0772762) to Professor Stough, Dr. Owens, and Dr. Ogden.…”

Examining the effect of dl-3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine on the standardized field sobriety tests

“…Amphetamine usage by professional drivers and young adults attending late or all night parties has been recognized as playing a contributory role in the increase of driving injuries and deaths of drivers testing positive to stimulants [7]. Given that these amphetamine preparations have reported transient cognitive and mood enhancing properties, and their consumption appears to compromise driving ability, whether through increased risk taking behavior [8] or alternatively cognitive disturbance of functions necessary to drive in a safe and legal manner, examination of their effect on SFST performance is necessary to elucidate what SFSTs are compromised upon MDMA or methamphetamine consumption. The purpose of this paper is to explore the effect of two commonly used amphetamine type stimulants, MDMA and d-methamphetamine, on SFST performance.…”