In the United States, motor vehicle accidents remain one of the primary causes of mortality among young adults. While preventive measures targeting alcohol-impaired driving (DUI-A) have contributed to reducing driving impairments associated with alcohol use, limited attention and research and prevention efforts have been dedicated to cannabis-impaired driving (DUI-C) and the combined effects of alcohol and cannabis use on driving impairment (DUI-SAM). Prior research highlights the significant role of social norms in influencing high-risk driving behaviors; however, there is a notable lack of systematic investigation into both descriptive and injunctive norms specifically related to simultaneous alcohol and cannabis use and subsequent driving impairment. To address this gap, the current study aims to examine the relationship between perceived descriptive and injunctive norms concerning SAM-impaired driving behaviors and self-reported driving-related behaviors among young adults in Washington State.
The study employed data from the 2019 cohort of the Washington Young Adult Health Survey, which included 1,941 young adults aged 18-25 living in Washington State. Participants completed a web-based survey measuring the frequency of DUI-SAM and RWI-SAM, perceived descriptive norms about these behaviors, and injunctive norms reflecting their community’s perceived approval or disapproval of these actions. The collected data were analyzed through multivariable logistic regression models.
The study findings revealed that 2.7% of participants reported driving under the influence of simultaneous alcohol and cannabis use in the past month, while 5.3% reported riding with a SAM-impaired driver (RWI-SAM). These behaviors were less common compared to alcohol-only (11.5%) and cannabis-only (12.4%) impaired driving. However, nearly half of the participants perceived these behaviors as frequent, with 49.8% believing DUI-SAM and 48.7% believing RWI-SAM occurred at least once per month. Descriptive norms demonstrated a limited association with self-reported behaviors. While a higher perceived prevalence of RWI-SAM among peers was linked to increased odds of engagement, no significant relationship was found for DUI-SAM. In contrast, injunctive norms, reflecting perceived acceptability, were strong predictors. Participants with permissive attitudes toward DUI-SAM were 3.8 times more likely to engage in the behavior, and those with permissive views on RWI-SAM were 2.94 times more likely to ride with a SAM-impaired driver. These findings suggest that targeting injunctive norms related to SAM-impaired driving could have a broader impact on reducing various types of impaired driving among young adults.
Takeaway: Addressing permissive attitudes toward simultaneous alcohol and cannabis (SAM)-impaired driving could help reduce SAM-related and other impaired driving behaviors among young adults.