1 Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA.
2 Department of Psychology, University of Southern California, Los Angeles, CA, USA.
J Psychopharmacol. 2018 Mar;32(3):302-308. doi: 10.1177/0269881117748901. Epub 2018 Jan 17.
While individual differences in reward sensitivity are believed to generalize across drugs and alternative rewards, this notion has received little empirical attention in human research. Here, we tested whether individual differences in the subjective rewarding effects of physical activity were associated with the subjective response to d-amphetamine administration. Healthy volunteers ( n=95; age 18-35 years) completed questionnaires measuring the self-reported pleasurable effects of physical activity and other covariates, and this was followed by two double-blind counterbalanced sessions during which they received either 20 mg oral d-amphetamine or placebo. Subjective drug effects measures were collected before and repeatedly after drug administration. Subjective d-amphetamine-related effects were then reduced via principal components analysis into latent factors of "positive mood," "arousal," and "drug high." Multiple regression models controlling for placebo-related scores, session order, demographics, body mass index, level of physical activity, and use of other drugs showed that degree of self-reported physical activity reward was positively associated with d-amphetamine-induced positive mood and arousal ( βs≥0.25, ps≤0.04), but was not associated with d-amphetamine-induced changes in drug high ( β=0.13, p=0.24). These results provide novel evidence suggesting that individual differences in reward sensitivity cross over between d-amphetamine reward and physical activity reward in humans.
虽然人们普遍认为，对奖赏的敏感性存在个体差异，这种差异会体现在不同药物和其他奖赏上，但人类研究对此关注甚少。在此，我们测试了个体对体育活动主观奖赏效应的差异是否与个体对安非他命给药的主观反应有关。健康志愿者（n=95；年龄 18-35 岁）完成了衡量体育活动的自我报告愉悦效应和其他协变量的问卷，随后进行了两次双盲对照实验，在此期间，他们分别接受了 20 毫克口服安非他命或安慰剂。给药前和给药后反复收集了主观药物效应测量值。然后通过主成分分析将与药物相关的主观效应分为“积极情绪”、“兴奋”和“药物快感”三个潜在因素。控制安慰剂相关评分、实验顺序、人口统计学、体重指数、身体活动水平和其他药物使用的多元回归模型显示，自我报告的体育活动奖赏程度与安非他命引起的积极情绪和兴奋呈正相关（βs≥0.25，ps≤0.04），但与安非他命引起的药物快感变化无关（β=0.13，p=0.24）。这些结果提供了新的证据，表明人类对奖赏的敏感性个体差异存在于安非他命奖赏和体育活动奖赏之间的交叉。
