Research: Increased motor vehicle deaths linked to cannabis use in states with legal markets

States with legal recreational cannabis markets had a 10% increase in MVA deaths



By Bill Carey

CHICAGO — A new study from the University of Illinois Chicago looked at death certificate data and compared mortality rates in states that legalized recreational cannabis dispensaries versus states that only provided access to medical cannabis.

Researchers found a substantial increase in crash fatalities in four of the seven states in the study with legalized recreational markets. On average, recreational markets were associated with a 10% increase in motor vehicle accident deaths, UIC Today reported.

“To see a 10% increase in motor vehicle accident deaths associated with recreational markets is concerning. Previous studies have found cannabis impairs driving ability and that driving while high is fairly common among regular cannabis users,” said Samantha Marinello, one of the study’s authors. 

Marinello and Lisa Powell, UIC distinguished professor and director of the division, focused on seven states that implemented legal recreational cannabis markets: Alaska, California, Colorado, Massachusetts, Nevada, Oregon and Washington. They looked at death certificate data from 2009-2019 on deaths in three areas linked to cannabis use but are poorly understood: motor vehicle accidents, suicide and opioid overdose.

“We didn’t want to compare states with very different mortality trends or social ideology, so we looked at each state and outcome and identified comparison states with existing medical cannabis programs and with similar pre-trends to conduct our analysis,” said Marinello.  

The data showed significant increases in crash fatalities in Colorado (16%), Oregon (22%), Alaska (20%) and California (14%). “The results suggest that a potential unintended consequence of recreational markets is increased cannabis-intoxicated driving and crash deaths, and, hence, a potential need for policies focused on reducing driving under the influence of cannabis,” said the study’s authors.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities” is published in the Social Science & Medicine journal.