Age-varying time trends in cannabis- and alcohol-related risk perceptions 2002-2019

Alcohol- and cannabis-related risk perceptions are strong predictors of use behavior. Studies suggest that attitudes toward cannabis are becoming increasingly permissive, however studies have yet to comprehensively a) compare time trends in cannabis-related attitudes to those of other commonly used substances, such as alcohol, and b) test whether trends significantly differ by age.

Public access data from the National Study on Drug Use and Health from 2002 to 2019 were used (N = 1,005,421). Structural Equation Models tested whether study year (linear trend), was associated with alcohol- and cannabis-related risk perceptions (correlated outcomes), and whether age (adolescence [12-17], emerging adulthood [18-25], adulthood [26-35], middle adulthood [36-49], and older adulthood [50+]) moderated time trends. Sex, race/ethnicity, and use frequency were covaried.

The linear trend of study year was associated with decreased cannabis-related risk perceptions (p < .001). There was also a significant interaction of age by study year for cannabis-related risk perceptions, such that adults, emerging adults, and middle adults had the largest decrease in attitudes over time. For alcohol-related risk perceptions, the linear trend of study year was significantly associated with increased risk perceptions (p = .001), but the interaction of time by age was non-significant; alcohol-related effects were extremely small (b < 0.01).

Findings suggest that cannabis-related risk perceptions are becoming more permissive with time across ages, but particularly in adults, emerging adults, and middle adults. In contrast, alcohol-related risk perceptions have stayed relatively stable over time, with only negligible increases. Findings underscore the importance of targeting permissive cannabis-related attitudes via prevention efforts.