Dar Reuven, Barrett Sean P
School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel
Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada.
J Psychopharmacol. 2014 Nov;28(11):1071-9. doi: 10.1177/0269881114548295. Epub 2014 Sep 24.
The placebo effect of a psychoactive drug can be defined as the effect of expecting the drug in the absence of its pharmacological actions. As nicotine is widely believed to be the primary factor driving cigarette smoking, smokers are likely to expect nicotine to alleviate craving and withdrawal. The present review examines the extent to which any observed effects of nicotine, and especially its craving- and withdrawal-reducing effects, can be attributed to placebo. We begin by reviewing studies that examined the placebo effects of nicotine in the laboratory and follow with a review of potential placebo effects that are typically not controlled in placebo-controlled studies of nicotine replacement therapy (NRT). In laboratory studies, nicotine instructions decrease tobacco smoking, craving and/or withdrawal, while nicotine-specific effects have not been consistently reported. In field trials of NRT, there is a general failure to assess smokers' beliefs regarding their drug assignment. This omission makes it difficult to unequivocally attribute findings of placebo-controlled NRT studies to the physiological effects of nicotine. In sum, our review indicates that the placebo effects of nicotine, and specifically nicotine content expectations, may account for many of the benefits associated with nicotine delivery devices in both laboratory and field studies.
精神活性药物的安慰剂效应可定义为在没有药物药理作用的情况下对药物的预期所产生的效应。由于尼古丁被广泛认为是导致吸烟的主要因素，吸烟者可能期望尼古丁能缓解烟瘾和戒断反应。本综述探讨了观察到的尼古丁效应，尤其是其减少烟瘾和戒断反应的效应，在多大程度上可归因于安慰剂。我们首先回顾在实验室中研究尼古丁安慰剂效应的研究，接着回顾在尼古丁替代疗法（NRT）的安慰剂对照研究中通常未得到控制的潜在安慰剂效应。在实验室研究中，尼古丁指示会减少吸烟、烟瘾和/或戒断反应，而尼古丁的特定效应并未得到一致报道。在NRT的现场试验中，普遍未能评估吸烟者对其药物分配的信念。这一疏漏使得难以明确地将安慰剂对照的NRT研究结果归因于尼古丁的生理效应。总之，我们的综述表明，尼古丁的安慰剂效应，特别是对尼古丁含量的预期，可能是实验室和现场研究中与尼古丁递送装置相关的许多益处的原因。
