Article

Further evidence for individual differences in placebo responding: An interactionist perspective

Department of Psychology, University of Toledo, Toledo, Ohio, United States
Journal of Psychosomatic Research (Impact Factor: 2.84). 06/2007; 62(5):563-70. DOI: 10.1016/j.jpsychores.2006.12.005
Source: PubMed

ABSTRACT A prior investigation found that individuals low in optimism are more likely to follow a negative placebo (nocebo) expectation. The present study tested the hypothesis that individuals high in optimism are more likely to follow a positive placebo expectation.
Individuals (N=56) varying in their level of optimism were randomly assigned to one of three conditions. In the first condition, participants were given the expectation that a placebo sleep treatment would improve their sleep quality (placebo expectation condition). In the second condition, participants engaged in the same sleep treatment activity but were not given the positive placebo expectation (treatment control condition). Finally, a third group did not receive the positive placebo expectation and also did not engage in the placebo sleep treatment (no-placebo control condition).
Optimism was positively associated with better sleep quality in the placebo expectation condition (r=.48, P<.05). Optimism scores were not associated with better sleep quality in either the treatment control condition (r=-.17, P=.46) or the no-placebo control condition (r=-.24, P=.35).
Dispositional optimism relates to placebo responding. This relationship, however, is not manifested in a simple increase or decrease in all types of placebo responding. Rather, it appears that, as optimism increases, response to the positive placebo expectation increases, whereas response to nocebo expectation decreases. It is recommended that future research on personality and placebo effects consider the interaction between situational and dispositional variables.

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    • "For example, extraversion predicted placebo induced improvements in irritable bowel syndrome symptoms only in the presence of an empathic practitioner [7]. Empathic concern was only related to placebo analgesic responses in a social learning condition that involved a confederate [6], and the link between optimism and responding may only eventuate in positively valenced contexts [13] [14]. "
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    ABSTRACT: Aim: To identify personality traits related to placebo responding outside the context of pain. Methods. 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 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. Results. 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. Conclusion. 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.
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    • "The individual psychological characteristics of suggestibility, neuroticism, and social desirability were additionally assessed, because these characteristics may affect the magnitude of nocebo and placebo effects [14] [21] [22]. Therefore, the following validated questionnaires investigating individual psychological characteristics had been filled out within 1 week before the testing took place. "
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    Pain 02/2011; 152(7):1486-94. DOI:10.1016/j.pain.2011.01.043 · 5.84 Impact Factor
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    • "Az énhatékonyság abban való hit, hogy képesek vagyunk végrehajtani valamit. Korábbi kutatási eredmények alapján (Geers, Helfer, Kosbab, Weiland és Landry, 2005; Geers, Kosbab, Helfer, Weiland és Wellman, 2007) a szerzők szerint pozitív kapcsolat van a placebo válaszkészség és az optimizmus között (Buckalew és Ross, 1981; Scheier és Carver, 1985; Walach, Schmidt, Dirhold és Nosch, 2002). "
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    ABSTRACT: A brief theoretical discussion of the placebo effect and of some methodological issues of the measurement of it are followed by a narrative review based on the results of our earlier metaanlysis of fourteen published research on the investigation of placebo effect in sports and exercise. Various factors (e.g. personality factors, perceptual characteristics of the applied substance or treatment) of placebo-effect effecting performance in sports and relevant research are also addressed. Absztrakt A placebo-hatás rövid elméleti áttekintését, valamint a placebo-hatás mérésének néhány módszertani problematikájának bemutatását korábbi metaanalízisünkön alapuló, különböző sportokban végzett placebo-hatás vizsgálatok narratív összefoglalója követi. A sportban megfigyelhető placebo-hatás különböző, a teljesítményt is befolyásoló összetevőit (pl. személyiség, az alkalmazott szer perceptuális tulajdonságai) vizsgáló kutatásokat is ismertetünk.
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