CDART - Center for Drug Abuse Research Translation - Minority Supplemnt

Summary of Parent Project 3 (Center for Drug Abuse Research Translation) To optimally design targeted interventions aimed at reducing substance use, one must know which characteristics or traits are involved in substance use and, ideally, how these characteristics lead to substance use. However, the relations among traits, their underlying processes, and substance use are likely to be complex and involve bi- directional influences. To study these relations, important traits and the processes underlying them must be specified and studied in relation to substance use across time. Previous research has shown that impulsive sensation seeking (ISS) is a robust risk factor for substance use, but recent research suggests that ISS is not a unitary construct. Although the best names for the separable aspects may be open to debate, at least two aspects have been identified--reward seeking defined as a tendency to enjoy and pursue exciting activities and new experiences and low inhibition defined as the tendency to act without thinldng or reflection. Lynam and colleagues in Project 3, have shown that each trait independently predicts substance use and abuse. These differential relations may be due to differences in the processes underlying each trait. Project 3 is examining reward seeking and inhibition as separable risk factors for substance use, identifying the elemental and social processes underlying the relation between each trait and substance use, and examining the effect of substance use on each trait and its associated processes. The research examines elemental processes that assess one of two hypothetical systems: an approachlreward seeking system and an inhibitory system. The reward system is theorized to be responsive to reward and is responsible for activating approach behavior. The inhibition system is theorized to be sensitive to punishment and is responsible for inhibiting ongoing behavior and initiating active information processing. An overactive approach system, an underactive inhibition system, and a cognitive system (e.g., working memory) that operates slowly with a small capacity have each been linked to substance use and abuse. In addition, several social variables, previously linked to drug use, which can be influenced by these same underlying systems are being examined. The research examines these processes in a longitudinal design that allows specification of bi- directional influence. There are three primary specific aims: 1. To identify the mechanisms underlying the relations leading from reward seeking and inhibition to substance use. It is predicted that reward seeking will be associated with drug use through mechanisms dealing with approach and positive incentive motivation. It is predicted that low inhibition will be associated with drug use through mechanisms regulating inhibition, withdrawal, and reflection. 2. To examine the effect of substance use on the elemental processes associated with reward seeking and inhibition. It is predicted that thug and alcohol use, in terms of initiation or escalation, will predict impaired functioning of the systems under study. 3. To examine the relations among the underlying elemental processes themselves. We hypothesize that tasks assessing approach behavior, including reaction time to go targets in the cued Go/No go Task, Balloon Analogue Risk Task, cardiac pre- ejection period during reward, and greater left hemisphere activation will intercorrelate with one another providing evidence of a coherent system.