Placebo and Nocebo Effects in Chronic Pain Patients
How Expectations and Emotional Feelings Contribute to the Experience of Pain
Abstract
Placebo, as well as nocebo, effects have been primarily investigated in studies with healthy volunteers exposed to acute experimental pain. Yet with regard to chronic pain patients, there is emerging evidence for significant placebo effects but not for nocebo effects. Expectations of pain relief are known to contribute to placebo effects, and lately the influence of emotional feelings has also been investigated. In this line of research, an experiential method has been applied to capture the emotional feelings that chronic pain patients experience during placebo and nocebo interventions. The findings indicate that the patients’ expectations of treatment effects are highly embedded in their emotional feelings. Hence, in order to optimize placebo factors in the clinical treatment of patients, it may be pivotal to investigate and enhance both expectancies and emotional feelings about treatments.
References
2009). Placebo effects: Understanding the mechanisms in health and disease. Oxford, UK/New York, NY: Oxford University Press.
(2011). The effect of treatment expectation on drug efficacy: Imaging the analgesic benefit of the opioid remifentanil. Science Translational Medicine, 3, 70ra14.
(2013). Placebo and pain: From bench to bedside. Burlington, MA: Elsevier.
(1997). Toward a neurobiology of placebo analgesia. In , The placebo effect. An interdisciplinary exploration (pp. 93–116). Cambridge, MA: Harvard University Press.
(2013). Positive and negative emotions and placebo analgesia. In , Placebo and pain: From bench to bedside (pp. 73–81). Burlington, MA: Elsevier.
(2011). The relation of emotions to placebo responses. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 366, 1818–1827.
(2001). Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment. The New England Journal of Medicine, 344, 1594–1602.
(2004). Is the placebo powerless? Update of a systematic review with 52 new randomized trials comparing placebo with no treatment. Journal of Internal Medicine, 256, 91–100.
(2010). Placebo interventions for all clinical conditions. The Cochrane Database of Systematic Reviews, 1, CD003974 doi: 10.1002/14651858.CD003974.pub3
(2011). Investigating pristine inner experience: Moments of truth. New York, NY: Cambridge University Press.
(2001). Telling what we know: Describing inner experience. Trends in Cognitive Sciences, 5, 400–403.
(2013). Smerter. Baggrund, evidens og behandling
([Pain. Background, evidence, and treatment] . Copenhagen, Denmark: FADLs.2010). Placebos without deception: A randomized controlled trial in irritable bowel syndrome. PloS One, 5, e15591.
(2008). Components of placebo effect: Randomised controlled trial in patients with irritable bowel syndrome. BMJ (Clinical Research Ed.), 336, 999–1003.
(2013). The effect of treatment history on therapeutic outcome: An experimental approach. JAMA Internal Medicine, 173, 1468–1469.
(2013). The potential of the analgesic placebo effect in clinical practice–recommendations for pain management. In , Placebo and pain: From bench to bedside (pp. 267–275). Burlington, MA: Elsevier.
(2007). Classical conditioning and expectancy in placebo hypoalgesia: A randomized controlled study in patients with atopic dermatitis and persons with healthy skin. Pain, 128, 31–39.
(1997). Classical conditioning and the placebo effect. Pain, 72, 107–113.
(2014). The magnitude of nocebo effects in pain: A meta-analysis. Pain. Advance online publication. doi: 10.1016/j.pain.2014.04.016.
(2014). Expectations and positive emotional feelings accompany reductions of decrease in ongoing and evoked neuropathic pain following placebo interventions. Manuscript in preparation.
(2012). Placebo manipulations reduce hyperalgesia in neuropathic pain. Pain, 153, 1292–1300.
(2011). Decreased pain inhibition in irritable bowel syndrome depends on altered descending modulation and higher-order brain processes. Neuroscience, 195, 166–175.
(2001). Response expectancies in placebo analgesia and their clinical relevance. Pain, 93, 77–84.
(1999). Psychological mechanisms of pain and analgesia. Seattle, WA: IASP Press.
(1984). Some general laws of human emotion: Interrelationships between intensities of desire, expectation and emotional feeling. Journal of Personality, 52, 389–409.
(2012). Inner experience and neuroscience: Merging both perspectives. Cambridge, MA: MIT Press.
(2007). Placebo analgesia is accompanied by large reductions in pain-related brain activity in irritable bowel syndrome patients. Pain, 127, 63–72.
(2008). A comprehensive review of the placebo effect: Recent advances and current thought. Annual Review of Psychology, 59, 565–590.
(1999). An analysis of factors that contribute to the magnitude of placebo analgesia in an experimental paradigm. Pain, 83, 147–156.
(2003). Reliable differences in placebo effects between clinical analgesic trials and studies of placebo analgesia mechanisms. Pain, 104, 715–716.
(2013). The contribution of Desire, Expectation and Reduced Negative Emotions to Placebo Anti-hyperalgesia in Irritable Bowel Syndrome. In , Placebo and pain: From bench to bedside (pp. 215–26). Burlington, MA: Elsevier.
(2007). Individual differences in reward responding explain placebo-induced expectations and effects. Neuron, 55, 325–336.
(2011). Patients’ direct experiences as central elements of placebo analgesia. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 366, 1913–1921.
(2013). Conceptualization and magnitudes of placebo analgesia effects across meta-analyses and experimental studies. In , Placebo and pain: From bench to bedside (pp. 203–213). Burlington, MA: Elsevier.
(2009). Factors contributing to large analgesic effects in placebo mechanism studies conducted between 2002 and 2007. Pain, 145, 36–44.
(2004). The contribution on changes in expected pain levels and desire for pain relief to placebo analgesia. In , Psychological methods of pain control: Basic science and clinical perspectives (pp. 207–234). Seattle, WA: IASP Press.
(2002). A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia. Pain, 99, 443–452.
(2003). The contributions of suggestion, desire, and expectation to placebo effects in irritable bowel syndrome patients. An empirical investigation. Pain, 105, 17–25.
(2005). Increased placebo analgesia over time in irritable bowel syndrome (IBS) patients is associated with desire and expectation but not endogenous opioid mechanisms. Pain, 115, 338–347.
(2003). Reversal of visceral and cutaneous hyperalgesia by local rectal anesthesia in irritable bowel syndrome (IBS) patients. Pain, 105, 223–230.
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