Up in smoke or bottoms up: How policy could affect substance abuse

January 12, 2015

Half of young drivers who died in car crashes in American states such as California, Hawaii and West Virginia were under the influence of either alcohol or marijuana, or both. This is the story told by the statistics recording fatal road accidents involving 16- to 25-year olds in nine US states. It was used by researchers from Columbia University's Mailman School of Public Health to gauge how possible policy changes could influence substance use among adolescents and young adults. The study, led by Dr. Katherine Keyes, is published in Springer's Injury Epidemiology, an open access journal.

Keyes and her colleagues analyzed 7,191 involving drivers between the ages of 16 and 25 from the states of California, Connecticut, Hawaii, Illinois, New Hampshire, New Jersey, Rhode Island, Washington State and West Virginia. These nine states all routinely perform toxicological tests on the blood or urine specimens of drivers who die in . Information was drawn from the Fatality Analysis Reporting System, a census of fatal traffic crashes occurring within the US. More than half of the crashes (54.7 percent) included for the period between 1999 to 2011 occurred in California.

Overall, 50.3% of the deceased tested positive for , or both. Of these, 36.8 percent were under the influence of alcohol, 5.9 percent used only marijuana and 7.6 percent used both substances.

Keyes's team further tested whether there were any changes in patterns of alcohol and marijuana use among those aged 21 years and older who were legally allowed to consume alcohol, versus those less than 21. It was found that alcohol consumption indeed increased by 14 percent, but such prominent changes in marijuana use were not seen. The Columbia University researchers do note that marijuana use decreased among those aged 21 years and older who used this drug alone. After reaching age 21, use of alcohol in combination of marijuana increased slightly.

"Given the rapid changes currently underway in marijuana availability and permissibility in the US, understanding the effects of drug control policies on substance use behaviour and adverse health outcomes, such as fatal motor vehicle crashes, has never been more important," says Dr. Keyes.

"Taken together, we found no significant substitution effect between alcohol and marijuana. Rather, increased availability seems to increase the prevalence of concurrent use of alcohol and marijuana," says Dr. Guohua Li, co-author of the study and Director of the Centre for Injury Epidemiology and Prevention at Columbia University.

Explore further: Marijuana use involved in more fatal accidents in Colorado

More information: Keyes. K.M. et al (2014). Effects of Minimum Legal Drinking Age on Alcohol and Marijuana Use: Evidence from Toxicological Testing Data for Fatally Injured Drivers Aged 16 to 25 Years, Injury Epidemiology, DOI 10.1186/s40621-014-0032-1

Related Stories

Marijuana use involved in more fatal accidents in Colorado

May 15, 2014
The proportion of marijuana-positive drivers involved in fatal motor vehicle crashes in Colorado has increased dramatically since the commercialization of medical marijuana in the middle of 2009, according to a study by University ...

Signs point to sharp rise in drugged driving fatalities

January 30, 2014
The prevalence of non-alcohol drugs detected in fatally injured drivers in the U.S. has been steadily rising and tripled from 1999 to 2010 for drivers who tested positive for marijuana—the most commonly detected non-alcohol ...

Marijuana use may double the risk of accidents for drivers

October 6, 2011
Over 10 million people age 12 or older are estimated to have driven under the influence of illicit drugs in the prior year, according to a 2009 National Survey on Drug Use and Health. While marijuana is the most commonly ...

Multiple drug use fueling drugged-driving fatalities: report

June 24, 2014
(HealthDay)—Drugged drivers involved in fatal crashes in the United States are more likely to test positive for prescription drugs, marijuana and multiple drugs than they were 20 years ago, a new study finds.

Marijuana's hazy contribution to highway deaths

September 2, 2014
Public officials and safety advocates worry there will be more drivers high on pot and a big increase in traffic deaths as states liberalize marijuana laws.

Drivers who test positive for drugs have triple the risk of a fatal car crash

September 25, 2013
Drugged driving has been a safety issue of increasing public concern in the United States and many other countries but its role in motor vehicle crashes had not been adequately examined. In a new study conducted at Columbia ...

Recommended for you

Different types of alcohol elicit different emotional responses

November 22, 2017
Different types of alcohol elicit different emotional responses, but spirits are most frequently associated with feelings of aggression, suggests research published in the online journal BMJ Open.

Air pollution linked to poorer quality sperm

November 22, 2017
Air pollution, particularly levels of fine particulate matter (PM2.5), is associated with poorer quality sperm, suggests research published online in Occupational & Environmental Medicine.

Sunrise and sunset guide daily activities of city-dwellers

November 21, 2017
Despite artificial lightning and social conventions, the dynamics of daylight still influence the daily activities of people living in modern, urban environments, according to new research published in PLOS Computational ...

Older men need more protein to maintain muscles

November 21, 2017
The amount of protein recommended by international guidelines is not sufficient to maintain muscle size and strength in older men, according to a new study.

Exercising and eating well are greater contributors to health than standing at work

November 21, 2017
By now you've probably heard the edict from the health community: Sitting is the new smoking. Perhaps you've converted to a standing desk, or maybe you have a reminder on your phone to get up once an hour and walk around ...

Motorcycle crashes cause five times as many deaths as car accidents, six times the health costs

November 20, 2017
Motorcycle accidents are costly in terms of lives and health care costs. Compared with car accidents, motorcycle accidents cause 3 times the injuries, 6 times the medical costs and 5 times the deaths, found new research in ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.