"Why can't I stop?" Testing a two-factor theory of impulsivity and its application to substance misuse

Abstract

The misuse of alcohol and illicit substances remains a significant public health concern throughout the world. Recent advances in the understanding of biobehavioural processes involved in substance misuse hold great promise for enhancing prevention and treatment efforts. Specifically, there is converging evidence from the fields of personality and addiction neuroscience suggesting impulsive behaviour, and substance abuse specifically, is related to individual differences in the functioning of two neuropsychological systems. The first system is involved in the sensitivity to, and drive to obtain, rewarding stimuli (manifested as trait Reward Drive). The second system is related to the modulation or inhibition of approach to reward within the context of potential punishment (manifested as trait Rash Impulsiveness). Three studies were conducted in order to investigate the utility of a two-dimensional approach to impulsivity and substance misuse, and the specific mechanisms through which each dimension might convey risk...