Cannabis-associated Impairments in Autobiographical Memory Specificity and the Fading Affect Bias

While the association between cannabis use and verbal and working memory impairment is well documented, the relationships between cannabis use and autobiographical memory are less understood. This study investigated the relationship between cannabis use and two phenomenon associated with autobiographical memory: the fading affect bias (FAB) and memory specificity. The FAB occurs when the intensity of affect associated with negative memories fades faster than the intensity of affect associated with positive memories. Memory specificity refers to the level of detail with which an event is recalled (with more details signifying more specificity). Few studies have examined the relationships between substance use and memory specificity or the FAB. Cannabis using (N = 47) and non-using (N = 52) participants recalled positive and negative autobiographical events, which they rated on affect intensity at the time of the original event and currently. Participants also recalled additional autobiographical memories using a free-recall procedure, which were coded for specificity. The affect of unpleasant events for cannabis users faded significantly less than for non-users, and memory specificity was lower in cannabis users compared to non-users

If It Walks Like a Duck…Is It a Duck?: A Mixed Methods Investigation of Differences Between Machiavellian and Non-Machiavellian Substance Users

Machiavellianism is a set of personality traits characterized by a cold and callous nature, a belief in engaging in manipulative tactics for personal gain, a cynical and distrusting view of others, and pragmatically moral stance. Behaviors and views of individuals with elevated Machiavellian traits can be seen to have a marked similarity with several behaviours and views of individuals with substance use issues, making it difficult to differentiate between them. Using a mixed-methods approach, this study sought to determine what distinguishes individuals who are high in Machiavellianism from those who are low in Machiavellianism but appear high in this set of personality traits due to their addictive behavior. Discerning this difference has ramifications for substance use treatment planning and delivery. Substance using undergraduate students, who were both high (N = 251) or low (N = 254) in Machiavellianism, completed a series of questionnaires related to attachment style, social connectedness, coping styles, motivation for treatment, readiness for change, and treatment expectations. Participants also completed 14 open-ended questions that elicited responses related to the nature of participants’ substance use, the situations in which use occurs, motivations for use, concerns related to use, the mental and physical impacts of use, the impacts of use on users’ relationships and life, attitudes toward substance use treatment, and alternative coping strategies. A significant and positive linear relationship was found between Machiavellianism and alcohol use, though no relationship was found between Machiavellianism and drug use. Having an avoidant coping style, autonomous or controlled motivation for stopping to use substances, and low treatment outcome expectancies, were significant predictors of Machiavellian grouping. Individuals who were high in Machiavellianism were more likely to feel less socially connected to others and to have an anxious-pre-occupied attachment style. Stage of readiness to change did not differ between those high and low in Machiavellianism. Qualitative accounts highlighted that those high in Machiavellianism reported accounts consistent with a higher likelihood of using alcohol alone to manage emotional distress, with having more pre- and post-use anxiety and depression, with having a higher likelihood of using leisure activities or sleep to distract themselves when substances are not available, and with a higher likelihood of being opposed or ambivalent towards treatment, compared to those low in Machiavellianism. Qualitative accounts of those low in Machiavellianism were consistent with using substances alone to relax during leisure time, with a higher likelihood of adjusting naturally to not using, when substances are not available, and to viewing the prospect of treatment more favorably, compared to those high in Machiavellianism. Consistency of quantitative and qualitative findings are discussed, and treatment implications of these findings are reviewed. Recommendations of modified dialectical behavioral therapy, motivational interviewing, and building a strong therapeutic alliance are made in the context of substance use treatment for those high in Machiavellianism