The Role of Impulsivity and Expectancies in Predicting Marijuana Use: An Application of the Acquired Preparedness Model

Impulsivity and substance use covary. Smith and Anderson’s acquired preparedness model proposes that impulsivity predicts substance use through a mediational model such that substance use expectancies mediate the relation between impulsivity and drug use. The present study seeks to examine the relation between positive urgency, an important component of impulsivity with specific relations to substance use behavior, marijuana expectancies, and marijuana use patterns. The study focused on a sample of frequent marijuana users (n = 3,616) and assessed positive urgency using the UPPS-P, expectancies using the Biphasic Marijuana Effects Scale, an adapted form of the Biphasic Alcohol Effects Scale to measure the sedative and stimulant properties of marijuana, and also assessed use patterns. Findings suggest that stimulant expectancies predict heavier, more frequent marijuana use than sedative expectancies and that marijuana expectancies vary based on the limb of marijuana intoxication. Examination of the acquired preparedness model revealed that positive urgency’s link to marijuana use was fully mediated by expectancies.