title: 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 55 mph (89 kph), the MDMA drivers followed 64 m closer to the LV and demonstrated 1.04 s 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.
authors.affiliation: Department of Biostatistics, University of Iowa, Iowa City, IA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dastrup
authors.forename: Monica N
authors.initials: MN
authors.lastname: Lees
authors.forename: Antoine
authors.initials: A
authors.lastname: Bechara
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Dawson
authors.forename: Matthew
authors.initials: M
authors.lastname: Rizzo
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000009:adverse effects* / Q000494:pharmacology; D000328:Adult; D001288:Attention; D001334:Automobile Driving; D001336:Automobiles; D003071:Cognition / Q000187:drug effects; D003072:Cognition Disorders / Q000139:chemically induced; D005260:Female; D005583:Fourier Analysis; D006213:Hallucinogens / Q000009:adverse effects* / Q000494:pharmacology; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000009:adverse effects* / Q000494:pharmacology; D018570:Risk Assessment; D012309:Risk-Taking; D012449:Safety; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D018759:Adrenergic Uptake Inhibitors; D006213:Hallucinogens; D013287:Illicit Drugs; D018817:N-Methyl-3,4-methylenedioxyamphetamine
references.citation: Addiction. 2006 Nov;101(11):1614-21
references.pmid: 17034441
references.citation: Psychopharmacology (Berl). 2000 Oct;152(3):230-48
references.pmid: 11105933
references.citation: Ann Intern Med. 2000 Oct 17;133(8):656; author reply 657-8
references.pmid: 11033599
references.citation: Ann Intern Med. 2000 Mar 7;132(5):354-63
references.pmid: 10691585
references.citation: Lancet. 1992 Aug 15;340(8816):384-7
references.pmid: 1353554
references.citation: J Psychopharmacol. 2006 Mar;20(2):302-11
references.pmid: 16510488
references.citation: J Neurol Neurosurg Psychiatry. 2000 Jun;68(6):719-25
references.pmid: 10811694
references.citation: Nat Neurosci. 2005 Nov;8(11):1458-63
references.pmid: 16251988
references.citation: Psychopharmacology (Berl). 1999 Apr;143(4):417-25
references.pmid: 10367560
references.citation: Psychopharmacology (Berl). 1998 Oct;139(3):261-8
references.pmid: 9784083
references.citation: Psychopharmacology (Berl). 2004 May;173(3-4):440-5
references.pmid: 14714102
references.citation: Ned Tijdschr Geneeskd. 1994 Sep 10;138(37):1850-5
references.pmid: 7935920
references.citation: Am J Drug Alcohol Abuse. 1992;18(3):331-41
references.pmid: 1357957
references.citation: J Forensic Sci. 2001 Nov;46(6):1426-33
references.pmid: 11714155
references.citation: J Psychopharmacol. 1998;12(1):79-83
references.pmid: 9584971
references.citation: Psychopharmacology (Berl). 1999 Jan;141(1):30-6
references.pmid: 9952062
references.citation: Neurology. 1998 Dec;51(6):1532-7
references.pmid: 9855498
references.citation: J Gambl Stud. 2003 Spring;19(1):23-51
references.pmid: 12635539
references.citation: Hum Psychopharmacol. 2001 Dec;16(8):557-577
references.pmid: 12404536
references.citation: Psychopharmacology (Berl). 2001 Jan 1;153(2):196-202
references.pmid: 11205419
references.citation: Psychopharmacology (Berl). 2006 Sep;187(4):467-75
references.pmid: 16830130
references.citation: Psychopharmacology (Berl). 2005 May;179(3):559-66
references.pmid: 15723231