Heavy alcohol and marijuana use are common in undergraduates and are associated with numerous use-related problems, whether one drug is consumed on its on (i.e., monodrug use) or if two or more are taken together at the same time (i.e., polydrug use). Several personality traits (i.e., anxiety sensitivity, sensation seeking, impulsivity, and hopelessness) are known to differentially relate to alcohol and marijuana use. Further, the literature suggests that substance use motives (i.e., enhancement, coping, social, and conformity) and depressive symptoms are associated with mono- and polydrug use. Study 1 (N = 361) investigated the relationship between heavy episodic drinking (HED), personality traits, and motives and found that each personality trait at Wave 1 was differentially related to motives for drinking at Wave 2. However, only coping-anxiety, coping-depression, and enhancement motives predicted HED (i.e., five or more drinks for men, or four or more drinks for women, during one occasion). Hopelessness and anxiety sensitivity predicted depressive symptoms, athough depressive symptoms, in turn, did not predict HED. Study 2 (N = 57) investigated personality traits and motives associated with one form of polydrug use known as simultaneous polydrug use (i.e., use at the same time or in close temporal proximity). Results revealed that hopelessness was the only personality trait to predict a motive for simultaneous polydrug use (i.e., coping-depression motives). No motives were predictive of simultaneous polydrug use. Both hopelessness and anxiety sensitivity were predictive of depressive symptoms. In summary, individuals who engage in either mono- or simultaneous polydrug use may be more likely to have sensation seeking as a prominent personality trait. Those who specifically engage in the simultaneous polydrug use of alcohol and marijuana may also be more likely to endorse different personality traits and motives for use than monodrug users.
Alcohol is a widely used substance among university students. There are several measures that are used to assess the consequences of alcohol consumption. However, current instruments fail to capture several behavioural consequences established in literature. Negative consequences missing from existing measures are related to sexual behaviour, suicidal and non-suicidal self-injury, and criminal and delinquent behaviour. In addition to negative consequences, positive consequences have been neglected from these measures. The goal of this research was to develop a new measure that addresses these gaps. In Study One, items from current and widely used measures in research and clinical applications, as well as newly developed items, were administered to a sample of undergraduate students. Factor analysis and item performance indices (e.g., item to total scale correlations, item variance, relationship to desirable responding) were used to construct a new scale. In Study Two, the new scale was administered to assess indices of reliability and validity. Although many of the new behavioural consequences (e.g., suicidality, eating behaviours, and aggression) were eliminated from the scale through empirical methods of item retention, the final scale was found to perform well across nearly all indices; there was strong evidence of construct, concurrent, and convergent validity. The final scale was comprised of positive and negative consequences, with an index for valence ratings.