Abstract

ABSTRACT
Clarifying the revised Behavioural Inhibition System as a Risk Factor for Anxiety-Related Alcohol Misuse in Young Adulthood: New Insights from Experimental and Prospective Studies

Matthew Keough, Ph.D.
Concordia University, 2016

Theoretical models posit that anxious persons drink alcohol to self-medicate negative emotions. However, existing data suggest that the anxiety pathway is complex. While there is high comorbidity of anxiety and alcohol use disorders in adults, evidence earlier in the risk trajectory (in young adulthood) is highly mixed. Gray’s Reinforcement Sensitivity Theory (RST) provides a useful framework for clarifying the anxiety-drinking pathway in young adults. The RST implicates the behavioural inhibition system (BIS) as a risk factor for alcohol misuse. Important theoretical revisions were made to the BIS 15 years ago, but these changes have been slow to enter the empirical literature. The revised BIS is a motivational conflict system. In response to competing goals (e.g., reward vs. punishment), the revised BIS inhibits behaviour, giving rise to high anxiety, attention to threat, and behavioural ambivalence. Accordingly, BIS-anxiety may promote self-medication drinking, while sensitivity to motivational conflict may lead to indecisiveness about drinking and attention to threat. Theory suggests that a strong Behavioural Approach System (BAS) should enhance the anxiolytic effects of alcohol use, which should be salient to those high in the BIS. However, few studies have been able to examine these interactive effects since most work has not tested the predictions of the revised RST. Using experimental (Study 1) and prospective (Study 2) studies, the primary aim of this dissertation was to clarify the BIS-related pathway to alcohol misuse among young adults. Study 1 (N = 110) was an experimental design that aimed to examine the cognitive mechanisms of this pathway. Results demonstrated that individuals with a strong BIS and a strong BAS expected elevated positive mood (rather than reduced anxiety) in response to an alcohol cue when feeling anxious. Study 2 (N = 119) sought to examine the BAS as a moderator of BIS-risk for alcohol misuse during the transition out of university. Findings indicated that those high in the BIS showed impeded maturing out of alcohol misuse during this transition if they were also strong in BAS impulsivity. Conversely, young adults with a strong BIS rapidly reduced alcohol misuse if they were concurrently low in BAS impulsivity. Overall, the moderating role of the BAS clarified BIS-risk for alcohol misuse. Findings shed light on the cognitive mechanisms underlying BIS-related drinking and provide a first look on how the BIS and the BAS interact to set the stage for long-term alcohol problems in young adulthood.