Citation

Dahlgren MK, Sagar KA, Smith RT, Lambros AM, Kuppe MK, Gruber SA. Drug Alcohol Depend. 2020; ePub(ePub): ePub.

Affiliation

Cognitive and Clinical Neuroimaging Core, McLean Imaging Center, McLean Hospital, Belmont, MA, USA; Marijuana Investigations for Neuroscientific Discovery (MIND) Program, McLean Imaging Center, McLean Hospital, Belmont, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA. Electronic address: gruber@mclean.harvard.edu.

Copyright

(Copyright © 2020, Elsevier Publishing)

DOI

10.1016/j.drugalcdep.2019.107771

PMID

31952821

Abstract

BACKGROUND: Across the nation, growing numbers of individuals are exploring the use of cannabis for medical or recreational purposes, and the proportion of cannabis-positive drivers involved in fatal crashes increased from 8 percent in 2013 to 17 percent in 2014, raising concerns about the impact of cannabis use on driving. Previous studies have demonstrated that cannabis use is associated with impaired driving performance, but thus far, research has primarily focused on the effects of acute intoxication.

METHODS: The current study assessed the potential impact of cannabis use on driving performance using a customized driving simulator in non-intoxicated, heavy, recreational cannabis users and healthy controls (HCs) without a history of cannabis use.

RESULTS: Overall, cannabis users demonstrated impaired driving relative to HC participants with increased accidents, speed, and lateral movement, and reduced rule-following. Interestingly, however, when cannabis users were divided into groups based on age of onset of regular cannabis use, significant driving impairment was detected and completely localized to those with early onset (onset before age 16) relative to the late onset group (onset ≥16 years old). Further, covariate analyses suggest that impulsivity had a significant impact on performance differences.

CONCLUSIONS: Chronic, heavy, recreational cannabis use was associated with worse driving performance in non-intoxicated drivers, and earlier onset of use was associated with greater impairment. These results may be related to other factors associated with early exposure such as increased impulsivity.

Copyright © 2019 The Author(s). Published by Elsevier B.V. All rights reserved.

Language: en

Keywords

Age of onset; Cannabis; Driving; Executive function; Impulsivity; Marijuana; Safety