Neuropsychological, impulsive personality, and cerebral oxygenation correlates of undergraduate polysubstance use

While the relationship between cognitive deficits and impulsive-sensation seeking has been acknowledged in prior research, the impact of impulsive personality style on substance-related cognitive deficits has not been completely elucidated. The present study explored factors related to decision making and executive functioning in 23 polysubstance-using undergraduates and 23 healthy normal controls. Participants' cerebral oxygenation was measured using near-infrared spectroscopy. Polysubstance users performed worse on the Iowa Gambling Task (IGT), Wisconsin Card Sorting Test (WCST), and N-Back than did personality-matched controls. They also displayed less dorsolateral prefrontal oxygenation during the IGT. The polysubstance group reported more antisocial characteristics and lower positive affect; controlling for these variables eliminated group differences on the N-Back reaction time. Results suggest that cognitive decrements can be observed in polysubstance-using undergraduates without a lifetime burden of substance use, even after accounting for impulsivity. Results also highlight the importance of considering the contribution of positive mood and antisocial characteristics on executive functioning in polysubstance use.