Sci TM：病人情绪积极向上能够让止痛药的效果加倍

英国牛津大学、剑桥大学以及两所德国大学的科学家今日宣称，病人情绪积极向上能够让止痛药的效果加倍，而消极低沉则会让止痛药毫无作用，从而很可能证明了一种看法，即：疼痛乃心理作用。研究论文已被刊登在了医学杂志《转化医学》上面。

研究中，22名受试者均被安装了疼痛装置，使得他们的皮肤产生灼痛感。随后每人都被插入静脉注射管以输入止痛药。在药物输入之前，研究人员调查他们的疼痛程度，得到的疼痛平均指数为66。

接下来研究人员在不告知受试者的情况下输入止痛药，疼痛平均指数下降到了55。但在科学家告知受试者止痛药正被输入他们体内后，疼痛指数下跌至39。而在宣称停止输入止痛药后，疼痛指数又上升至64，而事实上药物输入过程并没有间断。

与此同时，研究人员还对受试者的脑部活动进行了MRI扫描。扫描结果显示，受试者以为自己没有被输入止痛药时，大脑的痛觉神经系统更为活跃。领导该研究的牛津大学教授艾琳称：“病人的负面预期会产生某种药理结果，大夫们不应忽视这种影响。”

推荐原文原文出处：

Sci Transl Med DOI: 10.1126/scitranslmed.3001244

The Effect of Treatment Expectation on Drug Efficacy: Imaging the Analgesic Benefit of the Opioid Remifentanil

Ulrike Bingel1,2,*, Vishvarani Wanigasekera1, Katja Wiech1, Roisin Ni Mhuircheartaigh1, Michael C. Lee3, Markus Ploner4 and Irene Tracey1

Abstract

Evidence from behavioral and self-reported data suggests that the patients’ beliefs and expectations can shape both therapeutic and adverse effects of any given drug. We investigated how divergent expectancies alter the analgesic efficacy of a potent opioid in healthy volunteers by using brain imaging. The effect of a fixed concentration of the μ-opioid agonist remifentanil on constant heat pain was assessed under three experimental conditions using a within-subject design: with no expectation of analgesia, with expectancy of a positive analgesic effect, and with negative expectancy of analgesia (that is, expectation of hyperalgesia or exacerbation of pain). We used functional magnetic resonance imaging to record brain activity to corroborate the effects of expectations on the analgesic efficacy of the opioid and to elucidate the underlying neural mechanisms. Positive treatment expectancy substantially enhanced (doubled) the analgesic benefit of remifentanil. In contrast, negative treatment expectancy abolished remifentanil analgesia. These subjective effects were substantiated by significant changes in the neural activity in brain regions involved with the coding of pain intensity. The positive expectancy effects were associated with activity in the endogenous pain modulatory system, and the negative expectancy effects with activity in the hippocampus. On the basis of subjective and objective evidence, we contend that an individual’s expectation of a drug’s effect critically influences its therapeutic efficacy and that regulatory brain mechanisms differ as a function of expectancy. We propose that it may be necessary to integrate patients’ beliefs and expectations into drug treatment regimes alongside traditional considerations in order to optimize treatment outcomes.