The Placebo Analgesic Effect in Healthy Individuals and Patients: A Meta-Analysis

Abstract

The findings suggest that patients benefited from placebo treatment to a greater degree than healthy individuals did and that studies on healthy individuals may underestimate the magnitude of the placebo analgesic effect in patients. Patients' clinical pain and experimentally induced pain respond to placebo to the same degree.

Reinterpreting homoeopathy in the light of placebo effects to manage patients who seek homoeopathic care: A systematic review

“…Furthermore, among works that support homoeopathy efficacy, one review studied individualised homoeopathy for fibromyalgia (Baranowsky et al, ) and the other one both individualised and non‐individualised homoeopathy for IBS (Peckham et al, ), health conditions recognised to show significant response to placebo (Supporting Information Table ) (Bradford & Meston, ; Brunoni, Lopes, Kaptchuk, & Fregni, ; Cepeda, Berlin, Gao, Wiegand, & Wada, ; Chen, Doherty, & Zhang, ; Dorn et al, ; Eredics, Madersbacher, & Schauer, ; Forsberg, Martinussen, & Flaten, ; Fulda & Wetter, ; Häuser, Bartram‐Wunn, Bartram, Reinecke, & Tölle, ; Hróbjartsson & Gøtzsche, ; Khan, Faucett, Lichtenberg, Kirsch, & Brown, ; Kuten‐Shorrer, Kelley, Sonis, & Treister, ; Lee, Malhotra, Creanga, Carlsson, & Glue, ; lovieno & Papakostas, ; Macedo, Farré, & Baños, ; Meissner, Distel, & Mitzdorf, ; Moncrieff, Wessely, & Hardy, ; Patel et al, ; Puhl, Reinhart, Rok, & Injeyan, ; Quinn & Colagiuri, ; Walsh, Seidman, Sysko, & Gould, ; Wilhelm, Winkler, Rief, & Doering, ; Yeung, Sharpe, Glozier, Hackett, & Colagiuri, ; Zhang, Robertson, Jones, Dieppe, & Doherty, ). Accordingly, these conditions tend to have good response to placebo in classical trial designs.…”

“…Several conditions show a greater response to placebos than others, and many studies were performed to assess the magnitude of placebo response in various conditions. Some of these placebo‐responsive conditions, both chronic and “short‐term” ones, are pain (and low back pain), IBS, hypertension, insomnia symptoms, women's sexual dysfunction, major depressive disorder, osteoarthritis, lower urinary tract symptoms, overactive bladder, restless legs syndrome, fibromyalgia, diabetic peripheral neuropathy, nausea, and burning mouth syndrome (Bradford & Meston, ; Brunoni et al, ; Cepeda et al, ; Chen et al, ; Dorn et al, ; Eredics et al, ; Forsberg et al, ; Fulda & Wetter, ; Häuser et al, ; Hróbjartsson & Gøtzsche, ; Khan et al, ; Kuten‐Shorrer et al, ; Lee et al, ; lovieno and Papakostas, ; Macedo et al, ; Meissner et al, ; Moncrieff et al, ; Patel et al, ; Puhl et al, ; Quinn & Colagiuri, ; Walsh et al, ; Wilhelm et al, ; Yeung et al, ; Zhang et al, ).…”

“…Even if more studies are needed to consider placebo treatments as an evidence‐based practice, current evidence about OLP treatments outline a promising field, and several clues already indicate the possible range of application of such treatments (Bradford & Meston, ; Brunoni et al, ; Carvalho et al, ; Cepeda et al, ; Chen et al, ; Dorn et al, ; Eredics et al, ; Forsberg et al, ; Fulda & Wetter, ; Häuser et al, ; Hoenemeyer et al, ; Hróbjartsson & Gøtzsche, ; Kam‐Hansen et al, ; Kaptchuk et al, ; Kelley et al, ; Khan et al, ; Kuten‐Shorrer et al, ; Lee et al, ; Locher et al, ; lovieno and Papakostas, ; Macedo et al, ; Meeuwis et al, ; Meissner et al, ; Moncrieff et al, ; Patel et al, ; Puhl et al, ; Quinn & Colagiuri, ; Sandler & Bodfish, ; Sandler et al, ; Schaefer et al, ; Walsh et al, ; Wilhelm et al, ; Yeung et al, ; Zhang et al, ). Data show that placebos may have a role in helping patients in different clinical conditions, for example individuals affected by different diseases may benefit from placebo effects for symptom relief (Forsberg et al, ; Locher et al, ; Meeuwis et al, ; Quinn & Colagiuri, ; Yeung et al, ). Therefore, placebo treatments may be harnessed by physicians in clinical practice.…”

Dopaminergic tone does not influence pain levels during placebo interventions in patients with chronic neuropathic pain

“…Importantly, a few studies indicate that the endogenous opioid system is not involved in placebo effects in chronic pain [38,74]. In general, no studies have so far been able to pharmacologically block placebo effects in chronic pain conditions, and as placebo effects in healthy volunteers might differ from those in chronic pain patients [23,64], it is important that the neurotransmitter systems involved in placebo effects in chronic pain is further investigated. Outcome variables: ongoing and evoked pain levels, predictor variables: expected pain levels and desire for pain relief.…”

Harnessing the placebo effect: a promising method for curbing the opioid crisis?

“…Analgesic properties of placebos were observed more than 60 years ago, when Henry Beecher gave saline injections to wounded soldiers in World War II after his morphine supply was exhausted . A recent meta‐analysis found that placebos were associated with very large decreases in pain among healthy volunteers and patients . Placebo analgesia is partially reversed by the opioid antagonist naloxone, suggesting that placebo pain‐relievers enhance endogenous opioid production .…”