Background: The psychomotor stimulant theory of addiction posits that sensitivity to the positively rewarding properties of alcohol puts certain individuals at higher risk for alcohol abuse. A valid and reliable index of overactivation in the reward system has been a heightened baseline heart rate (HR) increase on the ascending limb of the blood alcohol curve. The main goal of this study was to investigate the relationship between this HR response and a questionnaire measuring sensitivity to reward and sensitivity to punishment. Additional goals included looking at (1). the association between a high HR response and various personality traits (hopelessness/introversion, anxiety sensitivity, impulsivity, and sensation-seeking) and (2). the relationship between these personality traits and stimulant use.
Methods: A total of 18 low- and 19 high-HR responders completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ), the Substance Use Risk Profile Scale (SURPS), and a modified version of the Addiction Severity Index.
Results: High-HR responders obtained significantly higher scores than low-HR responders on the sensitivity to reward scale of the SPSRQ, as well as increased sensation-seeking scores on the SURPS. High-HR responders were not at significantly higher risk of having used stimulants, but stimulant use was associated with higher impulsivity scores on the SURPS.
Conclusions: Novelty/sensation-seeking is among the personality traits that have been linked to heavy alcohol use. This study suggests that reward sensitivity might mediate the relationship between this personality profile and drinking behavior.