Darragh Margot, Booth Roger J, Consedine Nathan S
Department of Psychological Medicine, University of Auckland, New Zealand.
Department of Psychological Medicine, University of Auckland, New Zealand.
J Psychosom Res. 2014 May;76(5):414-21. doi: 10.1016/j.jpsychores.2014.02.011. Epub 2014 Mar 11.
To identify personality traits related to placebo responding outside the context of pain.
Sixty three healthy volunteers completed the study. Personality traits were measured online one week prior to a laboratory session in which two psychosocial stress tests were administered. Prior to the second test, the placebo group received an intranasal spray of 'serotonin' (placebo) with the suggestion that it would enhance recovery. Subjective stress, heart rate and heart rate variability were measured. Self reported and physiological responses to the placebo suggestion were assessed against personality variables.
Placebo effects were demonstrated in both self reported and physiological stress metrics. Lower optimism and less empathic concern predicted greater perceived benefits from the placebo treatment; and lower drive, fun, and sensation seeking were related to a greater physiological response to the manipulation. Multivariate analyses revealed lower optimism and behavioural drive to be predictive of responding to the placebo manipulation.
Findings are in contrast with prior work in pain paradigms which found higher levels of the same traits to be related to greater placebo analgesic responses. A cluster of traits characterised by behavioural drive, extraversion, optimism and novelty or fun seeking appears to be germane to placebo responsiveness, but contextual stimuli may generate different patterns of responding. A new conceptualisation of placebo responsiveness may be useful. Rather than a 'placebo personality' it may be that responsiveness is better typified by a two faceted transactional model, in which different personality facets respond to different contextual contingencies.
识别疼痛背景之外与安慰剂反应相关的人格特质。
63名健康志愿者完成了该研究。在进行两项社会心理压力测试的实验室环节前一周，通过网络测量人格特质。在第二次测试前，安慰剂组接受了“血清素”（安慰剂）滴鼻喷雾，并被告知它会促进恢复。测量主观压力、心率和心率变异性。根据人格变量评估对安慰剂暗示的自我报告和生理反应。
在自我报告和生理压力指标中均显示出安慰剂效应。较低的乐观主义和较少的共情关注预示着从安慰剂治疗中能获得更大的感知益处；较低的驱力、乐趣和寻求刺激与对该操作有更大的生理反应有关。多变量分析显示较低的乐观主义和行为驱力可预测对安慰剂操作的反应。
研究结果与之前在疼痛范式中的研究工作相反，之前的研究发现相同特质的较高水平与更大的安慰剂镇痛反应相关。以行为驱力、外向性、乐观主义以及寻求新奇或乐趣为特征的一组特质似乎与安慰剂反应性密切相关，但情境刺激可能会产生不同的反应模式。对安慰剂反应性进行新的概念化可能会有所帮助。与其说是“安慰剂人格”，不如说反应性更适合用一个双方面的交互模型来描述，其中不同的人格方面对不同的情境意外事件做出反应。
