TY  - JOUR
A1  - Watkinson, A
A1  - Chapman, SCE
A1  - Horne, R
JF  - The Journal of Pain
SN  - 1528-8447
UR  - http://dx.doi.org/10.1016/j.jpain.2017.02.435
N1  - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions.
IS  - 8
SP  - 908
VL  - 18
KW  - Analgesia
KW  -  Natural remedies
KW  -  Pharmaceutical medicines
KW  -  Placebo effect
KW  -  Treatment beliefs
ID  - discovery1546802
N2  - This study examined whether placebo responses were predicted by a theoretical model of specific and general treatment beliefs. Using a randomised cross-over, experimental design (168 healthy individuals) we assessed whether responses to a cold pressor task were influenced by two placebo creams described as Pharmaceutical vs Natural origin. We assessed whether placebo responses were predicted by pre-treatment beliefs about the treatments (placebo) and by beliefs about the pain. The efficacy of both Pharmaceutical and Natural Placebos in reducing Pain Intensity was predicted by aspects of pain catastrophizing including Feelings of Helplessness (Pharmaceutical: B=0.03, p<0.01, Natural: B=0.02, p<0.05) and Magnification of Pain (Pharmaceutical: B=0.04, p<0.05, Natural: B=0.05, p<0.05) but also by pre-treatment Necessity beliefs (Pharmaceutical: B=0.21, p<0.01, Natural: B=0.16, p<0.05) and, for the Pharmaceutical condition, by more general beliefs in personal sensitivity to pharmaceuticals (B=0.14, p<0.05). Treatment Necessity beliefs also partially mediated the effects of Helplessness on placebo responses. Treatment Necessity beliefs for the Pharmaceutical Placebo were influenced by general pharmaceutical beliefs whereas Necessity beliefs for the Natural Placebo were informed by general background beliefs about holistic treatments. Our findings demonstrate that treatment beliefs influence the placebo effect suggesting that they may offer an additional approach for understanding the placebo effect. PERSPECTIVE: Placebo effects contribute to responses to active analgesics. Understanding how beliefs about different types of medicines influence placebo analgesia may be useful in understanding variations in treatment response. Using the cold-pressor paradigm we found that placebo analgesia is influenced by beliefs about natural remedies, pharmaceutical medicines and about pain.
EP  - 922
Y1  - 2017/08//
AV  - public
TI  - Beliefs about pharmaceutical medicines and natural remedies explain individual variation in placebo analgesia
ER  -