Approach behavior and sympathetic nervous system reactivity predict substance use in young adults.

A behavioral measure of approach (performance on a resource gathering task) in combination with sympathetic nervous system (SNS) reactivity was used to predict substance use in a sample of young adults (n=93). Pre-ejection period reactivity (PEP-R), a cardiac index of SNS reactivity, was recorded during the resource gathering task (task PEP - resting PEP). Higher levels of approach behaviors on the task in combination with less PEP-R (blunted SNS reactivity) predicted the highest levels of substance use. Findings are discussed in the context of behavioral and physiological systems of approach and avoidance.