Marijuana use, driving, and related cognitions.

The purpose of the present study was to examine cognitive risk factors for driving after use of marijuana. We tested whether marijuana outcome expectancies and specific cognitions about driving after marijuana use were uniquely associated with the likelihood and frequency of driving while high (DWH) and riding with a high driver (RWHD). Participants were college students recruited from introductory psychology classes at a Midwestern university who reported ever using marijuana in their lifetime and reported having access to a car or driving at least once a month (n = 506). Greater perceived dangerousness of DWH was associated with decreased likelihood of DWH and RWHD. Negative marijuana expectancies were associated with decreased likelihood of DWH, and social norms were associated with decreased likelihood of RWHD. All cognitive predictors were associated with decreased frequency of DWH and RWHD for individuals with the propensity to engage in these behaviors. Findings suggest interventions to reduce risk of DWH and RWHD may benefit from targeting general expectancies about the negative effects of marijuana. Similarly, results suggest increasing students' knowledge of the potential danger of DWH may help to reduce the likelihood and frequency of DWH and RWHD.