Positive expectancies mediate the association between sensation seeking and marijuana outcomes in at‐risk young adults: A test of the acquired preparedness model

BACKGROUND AND OBJECTIVES: The acquired preparedness model (APM) integrates personality trait research and psychosocial learning, which are theorized to ultimately increase risk for problematic substance use outcomes. METHODS: The present study uses the APM to examine the potential mediational role of positive and negative expectancies on the relationship between impulsivity and two marijuana outcomes (ie, frequency of use and marijuana use disorder [MUD] symptom count) among an at-risk sample of young adults with history of antisocial behavior and substance use in adolescence and their siblings (n = 312). RESULTS: Results suggest a significant indirect effect of sensation seeking on recent marijuana use through positive marijuana expectancies. There also was a significant indirect effect of sensation seeking on past-year MUD symptoms through positive expectancies. No significant indirect effects through negative expectancies were found for either outcome. DISCUSSION AND CONCLUSIONS: Our findings are consistent with the APM and suggest that higher sensation seeking is related to increased positive beliefs about marijuana outcomes, which is related to higher marijuana use and more MUD symptoms. SCIENTIFIC SIGNIFICANCE: These findings suggest that positive expectancies are an important risk factor for marijuana use and misuse, particularly for at-risk individuals with elevated rates of sensation seeking. Positive marijuana expectancies may be important to address in interventions for at-risk individuals. (Am J Addict 2018;XX:1-6).