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Background Previous research has shown that after one month of full dose nightly treatment with zolpidem (priming), subjects with chronic insomnia (CI) switched to intermittent dosing with medication and placebos were able to maintain their treatment responses. This approach to maintenance therapy is referred to as partial reinforcement. The present study sought to assess whether priming is required for partial reinforcement or whether intermittent dosing with placebos (50% placebos and 50% active medication) can, by itself, be used for both acute and extended treatment. Method 55 CI subjects underwent a baseline evaluation (Phase-1) and then were randomized to one of two conditions in Phase-2 of the study: one month of (1) nightly medication use with standard-dose zolpidem (QHS [n = 39]) or (2) intermittent dosing with standard-dose zolpidem and placebos (IDwP [n = 16]). In Phase-3 (three months), the QHS group was re-randomized to either continued QHS full dose treatment (FD/FD) or to IDwP dose treatment (FD/VD). Treatment response rates and Total Wake Time (TWT = [SL + WASO + EMA]) were assessed during each phase of the study. Results In Phase-2, 77% (QHS) and 50% (IDwP) subjects exhibited treatment responses (p = 0.09) where the average change in TWT was similar. In Phase-3, 73% (FD/FD), 57% (FD/VD), and 88% (VD/VD) of subjects exhibited continued treatment responses (p = 0.22) where the average improvement in TWT continued with FD/FD and remained stable for FD/VD and VD/VD (p Conclusion These results suggest that intermittent dosing with placebos can maintain effects but do not allow for the additional clinical gains afforded by continuous treatment.

Background and purpose — Emerging evidence from sham-controlled trials suggest that surgical treatment entails substantial non-specific treatment effects in addition to specific surgical effects. Yet, information on surgeons’ actual behaviors and beliefs regarding non-specific treatment and placebo effects is scarce. We determined surgeons’ clinical behaviors and attitudes regarding placebo effects. Methods — A national online survey was developed in collaboration with surgeons and administered via an electronic link. Results — All surgical clinics in Sweden were approached and 22% of surgeons participated (n = 105). Surgeons believed it was important for them to interact and build rapport with patients before surgery rather than perform surgery on colleagues’ patients (90%). They endorsed the importance of non-specific treatment effects in surgery generally (90%) and reported that they actively harness non-specific treatment effects (97%), including conveying confidence and calm (87%), building a positive interaction (75%), and making eye contact (72%). In communication regarding the likely outcomes of surgery, surgeons emphasized accurate scientific information of benefits/risks (90%) and complete honesty (63%). A majority felt that the improvement after some currently performed surgical procedures might be entirely explained by placebo effects (78%). Surgeons saw benefits with sham-controlled surgery trials, nevertheless, they were reluctant to refer patients to sham controlled trials (46%). Interpretation — Surgeons believe that their words and behaviors are important components of their professional competence. Surgeons saw the patient–physician relationship, transparency, and honesty as critical. Understanding the non-specific components of surgery has the potential to improve the way surgical treatment is delivered and lead to better patient outcomes.

ImportanceMethadone treatment is the most effective evidence-based treatment for opioid use disorder (OUD), but challenges related to dosing and premature treatment dropout argue for adjunct interventions to improve outcomes. One potential behavioral intervention with low risk involves harnessing placebo effects.ObjectiveTo determine the effect of a pharmacologically conditioned open-label placebo (C-OLP) on 90-day methadone dose, retention, drug use, withdrawal, craving, quality of life, and sleep.Design, Setting, and ParticipantsThis 2-arm, open-label, single-blind randomized clinical trial was conducted between December 5, 2017, and August 2, 2019, in an academically affiliated community opioid treatment program. Analyses were conducted between October 1, 2019, and April 30, 2020. A total of 320 newly enrolled adults seeking treatment for moderate to severe OUD were assessed for study eligibility; 131 met eligibility criteria, provided informed consent, and were randomized to either C-OLP or treatment as usual (TAU) in an unequal-block (3:2) manner. Exclusion criteria were pregnancy, hospital/program transfers, and court-ordered treatment.InterventionsParticipants randomized to C-OLP received pharmacologic conditioning and a placebo pill and methadone, and participants randomized to TAU were given methadone only. Participants met with the study team 5 times: at baseline (treatment intake) and 2, 4, 8, and 12 weeks postbaseline. Interactions were balanced between the 2 groups.Main Outcomes and MeasuresOutcomes included 90-day methadone dose (primary) and treatment retention, drug use, withdrawal, craving, quality of life, and sleep quality (secondary). Analyses were conducted as intention-to-treat.ResultsOf the 131 people enrolled in the study, 54 were randomized to TAU and 77 to C-OLP. Mean (SD) age was 45.9 (11.2) years; most of the participants were Black or African American (83 [63.4%]) and male (84 [64.1%]). No significant group differences were observed in the mean (SD) 90-day methadone dose (83.1 [25.1] mg for group TAU, 79.4 [19.6] mg for group C-OLP; t = 0.621991; P = .43), but the groups differed significantly in their retention rates: 33 (61.1%) for TAU and 60 (77.9%) for C-OLP (χ21 = 4.356; P = .04; number needed to treat for the beneficial outcome of 3-month treatment retention, 6; 95% CI, 4-119). C-OLP participants also reported significantly better sleep quality.Conclusions and RelevanceIn this randomized clinical trial, C-OLP had no effect on the primary outcome of 90-day methadone dose. However, C-OLP participants were significantly more likely to remain in treatment. These findings support the use of C-OLP as a methadone treatment adjunct, but larger trials are needed to further examine the use of C-OLP.Trial RegistrationClinicalTrials.gov Identifier: NCT02941809

This study investigated the efficacy of an open-label placebo (OLP) treatment for menopausal hot flushes. Women with at least five moderate or severe hot flushes per day were allocated to receive four weeks of OLP for twice a day or no-treatment. Intention-to-treat analyses included n = 100 women. In comparison to no-treatment, OLP reduced the log-transformed hot flush composite score (frequency × intensity) (mean difference in change: − 0.32, 95% CI [− 0.43; − 0.21], p d = 0.86), hot flush frequency (− 1.12 [− 1.81; − 0.43], p = 0.02, Cohen’s d = 0.51), and improved overall menopause-related quality of life (− 2.53 [− 4.17; − 0.89], p = 0.02, Cohen’s d = 0.49). Twelve (24%) (vs. three [6%]) patients had 50% lesser hot flushes. Problem rating of hot flushes and subdomains of quality of life did not improve. After four weeks, the OLP group was further divided via randomization to continue or discontinue the treatment. Benefits were maintained at week 8 (log-transformed score: − 0.04 [− 0.06; 0.14], p = 0.45). There was no difference between taking placebos for 8 or 4 weeks (log-transformed score: 0.04 [− 0.17; 0.25], p = 0.73). Results indicate that open-label placebos may be an effective, safe alternative for menopausal hot flushes.

BackgroundClinical trial articles often lack detailed descriptions of the methods used to randomize participants, conceal allocation, and blind subjects and investigators to group assignment. We describe our systematic approach to implement and measure blinding success in a double-blind phase 2 randomized controlled trial testing the efficacy of acupuncture for the treatment of vulvodynia.MethodsRandomization stratified by vulvodynia subtype is managed by Research Electronic Data Capture software’s randomization module adapted to achieve complete masking of group allocation. Subject and acupuncturist blinding assessments are conducted multiple times to identify possible correlates of unblinding.ResultsAt present, 48 subjects have been randomized and completed the protocol resulting in 87 subject and 206 acupuncturist blinding assessments.DiscussionOur approach to blinding and blinding assessment has the potential to improve our understanding of unblinding over time in the presence of possible clinical improvement.

This systematic review and meta-analysis investigates the frequency of adverse events in placebo groups compared with that in vaccine groups in COVID-19 vaccine trials., Key Points Question What was the frequency of adverse events (AEs) in the placebo groups of COVID-19 vaccine trials? Findings In this systematic review and meta-analysis of 12 articles including AE reports for 45 380 trial participants, systemic AEs were experienced by 35% of placebo recipients after the first dose and 32% after the second. Significantly more AEs were reported in the vaccine groups, but AEs in placebo arms (“nocebo responses”) accounted for 76% of systemic AEs after the first COVID-19 vaccine dose and 52% after the second dose. Meaning This study found that the rate of nocebo responses in placebo arms of COVID-19 vaccine trials was substantial; this finding should be considered in public vaccination programs., Importance Adverse events (AEs) after placebo treatment are common in randomized clinical drug trials. Systematic evidence regarding these nocebo responses in vaccine trials is important for COVID-19 vaccination worldwide especially because concern about AEs is reported to be a reason for vaccination hesitancy. Objective To compare the frequencies of AEs reported in the placebo groups of COVID-19 vaccine trials with those reported in the vaccine groups. Data Sources For this systematic review and meta-analysis, the Medline (PubMed) and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched systematically using medical subheading terms and free-text keywords for trials of COVID-19 vaccines published up to July 14, 2021. Study Selection Randomized clinical trials of COVID-19 vaccines that investigated adults aged 16 years or older were selected if they assessed solicited AEs within 7 days of injection, included an inert placebo arm, and provided AE reports for both the vaccine and placebo groups separately. Full texts were reviewed for eligibility by 2 independent reviewers. Data Extraction and Synthesis Data extraction and quality assessment were performed independently by 2 reviewers, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline and using the Cochrane risk-of-bias tool. Meta-analyses were based on random-effects models. Main Outcomes and Measures The primary outcomes were the proportions of placebo recipients reporting overall, systemic, and local (injection-site) AEs as well as logarithmic odds ratios (ORs) to evaluate group differences. Outcomes were tested for significance using z tests with 95% CIs. Results Twelve articles with AE reports for 45 380 participants (22 578 placebo recipients and 22 802 vaccine recipients) were analyzed. After the first dose, 35.2% (95% CI, 26.7%-43.7%) of placebo recipients experienced systemic AEs, with headache (19.3%; 95% CI, 13.6%-25.1%) and fatigue (16.7%; 95% CI, 9.8%-23.6%) being most common. After the second dose, 31.8% (95% CI, 28.7%-35.0%) of placebo recipients reported systemic AEs. The ratio between placebo and vaccine arms showed that nocebo responses accounted for 76.0% of systemic AEs after the first COVID-19 vaccine dose and for 51.8% after the second dose. Significantly more vaccine recipients reported AEs, but the group difference for systemic AEs was small after the first dose (OR, −0.47; 95% CI, −0.54 to −0.40; P

OBJECTIVE: There is growing evidence that open-label placebo (OLP) may be an efficacious treatment for chronic and functional conditions. However, patient-level predictors of response to OLP have not been clearly identified. The aim of this study is to evaluate psychological predictors of response to OLP and to compare this to double-blind placebo (DBP) and no-pill control (NPC). METHODS. This study is a secondary analysis of data collected in a six-week randomized controlled trial evaluating placebo effects in irritable bowel syndrome (IBS). The primary outcome was change in IBS severity. Hierarchical linear regression identified predictors of placebo response in general and compared them between those randomized to OLP, DBP, and NPC. Predictor variables included personality traits, generalized anxiety, depression, visceral sensitivity (a measure of symptom-specific anxiety), and pain catastrophizing. RESULTS. 210 participants (mean age 42.3, 73.3% female) were included. Regression models revealed that visceral sensitivity was a predictor of response to OLP and NPC but not DBP. Interestingly, the effects were opposite, with high visceral sensitivity predicting less improvement in NPC and more improvement in OLP. Pain catastrophizing was a negative predictor of response to OLP (i.e. high pain catastrophizing was associated with less improvement in OLP). Neither visceral sensitivity nor pain catastrophizing played a significant role for response to DBP. CONCLUSIONS. IBS participants who score low on the pain catastrophizing scale but high on the visceral sensitivity index seem to benefit particularly from OLP. Our study suggests that different psychological mechanisms may be involved in double-blind and open-label placebo interventions.

BackgroundIrritable bowel syndrome (IBS) is a highly prevalent chronic pain disorder with multiple underlying mechanisms and few treatments that have been demonstrated to be effective in placebo controlled trials. One potential reason may be the use of composite outcomes, such as the IBS Symptom Severity Scale (IBS-SSS) which includes descriptive items related to pain frequency and pain intensity as well as bowel dysfunction and bloating. We investigated if different features of IBS pain have distinct genetic associations and if these may be moderated by sex hormones.Participants and SettingAdult outpatients with moderately severe IBS (>175 on IBS-SSS) enrolled in a clinical trial reported IBS-SSS at baseline and after 6 weeks of therapy.MethodsFixed effects modeling was used to test the effect of COMT rs4680 genotype to change in pain severity (rated 0-100) and pain frequency (defined as number of days with pain in the past 10 days) from baseline to week 6 with IBS treatment. Parallel exploratory genome-wide association studies (GWAS) were also performed to identify single nucleotide polymorphisms (SNPs) associated with change in pain severity or pain frequency across all participants.ResultsA total of 212 participants (74% female) were included. The COMT rs4680 met allele was associated with decreased pain severity over the course of the trial in gene dosage models [beta(SE) −5.9 (2.6), P = 0.028]. Exploratory GWAS for change in pain frequency identified 5 SNPs in close proximity on chromosome 18 near L3MBTL4 which reached genome-wide significance (all P < 5.0E-8). This effect was not mediated by changing estradiol levels. There was also a region of chromosome 7 with 24 SNPs of genome-wide suggestive significance for change in pain severity (all P < 1.0E-5).ConclusionsPreviously reported association between COMT rs4680 genotype and treatment response as measured by IBS-SSS is related to pain severity, but not pain frequency. We also identified new candidate genes associated with changes in IBS pain severity (SNX13) and pain frequency (L3MBTL4) in response to treatment. Further studies are needed to understand these associations and genetic determinants of different components of IBS-SSS. ClinicalTrials.gov, Identifier: NCT0280224.

Many of the reported adverse events in clinical trials of irritable bowel syndrome are extraintestinal symptoms, which typically are assessed by open-ended questions during the trial and not at baseline. This may lead to misattribution of some pre-existing symptoms as side effects to the treatment.The current study analyzed data from a 6-week clinical trial of irritable bowel syndrome. Participants were randomized to receive double-blind peppermint oil, double-blind placebo, or treatment as usual. Extraintestinal symptoms were assessed at baseline and at the end of the study.This analysis included 173 participants (30 received double-blind peppermint oil, 72 received treatment as usual, and 71 received double-blind placebo). At baseline, each group reported approximately 5 extraintestinal symptoms per participant. The number of symptoms per participant decreased to an average of 3 by the end-of-study visit, and this change was statistically significant in all groups (P.001 for each group). When evaluating individual extraintestinal symptoms, the majority of participants did not report new/worse symptoms. In fact, between the baseline assessment and the final assessment, the average symptom severity decreased significantly in all 3 groups (P.001).Our study suggests that participants with irritable bowel syndrome often experience extraintestinal symptoms at baseline and that these symptoms generally improve in severity over the course of a clinical trial, regardless of the treatment arm. Systematic assessment of extraintestinal symptoms at the beginning of a clinical trial is necessary to determine more definitively whether these symptoms may be considered an adverse event attributable to a study medication.

The high prevalence and societal burden of chronic pain, its undertreatment, and disparities in its management have contributed to the acknowledgment of chronic pain as a serious public-health concern. The concurrent opioid epidemic, and increasing concern about overreliance on opioid therapy despite evidence of limited benefit and serious harms, has heightened attention to this problem. The biopsychosocial model has emerged as the primary conceptual framework for understanding the complex experience of chronic pain and for informing models of care. The prominence of psychological processes as risk and resilience factors in this model has prompted extensive study of psychological treatments designed to alter processes that underlie or significantly contribute to pain, distress, or disability among adults with chronic pain. Cognitive-behavioral therapy is acknowledged to have strong evidence of effectiveness; other psychological approaches, including acceptance and commitment therapy, mindfulness, biofeedback, hypnosis, and emotional-awareness and expression therapy, have also garnered varying degrees of evidence across multiple pain conditions. Mechanistic studies have identified multiple pathways by which these treatments may reduce the intensity and impact of pain. Despite the growing evidence for and appreciation of these approaches, several barriers limit their uptake at the level of organizations, providers, and patients. Innovative methods for delivering psychological interventions and other research, practice, and policy initiatives hold promise for overcoming these barriers. Additional scientific knowledge and practice gaps remain to be addressed to optimize the reach and effectiveness of these interventions, including tailoring to address individual differences, concurrently addressing co-occurring disorders, and incorporating other optimization strategies.

Open-label (honestly prescribed) placebos are an ethical way to evoke placebo effects in patients. As part of a mixed-methods study, we conducted in-depth interviews with eight menopausal women who underwent and benefitted from open-label placebo treatment in a randomized-controlled trial of hot flushes. Data were analyzed using Interpretative Phenomenological Analysis. We found that the women had low expectations about the placebo treatment yet endorsed what they referred to as “hope” and openness to “see what happens”. Recording hot flushes via the symptom diary was viewed as a valuable opportunity for self-examination and appraising outcomes. Receiving relief from the placebo treatment empowered women and enhanced their sense of control and agency. In summary, participants’ initial openness towards placebos, their hopes to get better, monitoring symptoms closely, and taking the initiative to address symptoms were components of a positive open-label placebo experience.

Previous studies have identified the gene, catechol-O-methyltransferase (COMT), as a primary regulator of sympathetic function. Although the COMT SNP rs4680 and rs4818, are well-studied, little is known about their influence on cancer-related fatigue (CrF) and placebo response. In this study, we examined whether genetic variation in COMT, at the functional SNP rs4680 and rs4818, influenced open-label placebo (OLP) responses found in cancer survivors reporting moderate to severe CrF and whether those responses differed by allele variation. We randomized cancer survivors (N=74) reporting moderate-to-severe CrF to receive OLP or to treatment-as-usual (TAU) and assessed if rs4680 and rs4818 were associated with changes in fatigue severity and fatigue-distressed quality of life. At the end of the initial 21 days, the treatments were crossed over and both groups were re-assessed. Decreases in fatigue symptom severity and fatigue-distressed quality of life across both genotypes (rs4680 and rs4818) were reported by participants when taking placebos. However, across all participants, only those with the high-activity G-allele (rs4680) and those with the rs4818 C/G combination reported significant decreases in fatigue severity and improvements in fatigue-distressed quality of life. Both COMT rs4680 high-activity G-allele and COMT rs4818 C/G were significantly associated with decreases in fatigue severity and improvements fatigue-distressed quality of life.

Background Previous studies have found widespread pain processing alterations in the brain in chronic low back pain (cLBP) patients. We aimed to (1) identify brain regions showing altered amplitude of low-frequency fluctuations (ALFF) using MRI and use these regions to discriminate cLBP patients from healthy controls (HCs) and (2) identify brain regions that are sensitive to cLBP pain intensity changes. Methods We compared ALFF differences by MRI between cLBP subjects (90) and HCs (74), conducted a discriminative analysis to validate the results, and explored structural changes in key brain regions of cLBP. We also compared ALFF changes in cLBP patients after pain-exacerbating manoeuvres. Results ALFF was increased in the post-/precentral gyrus (PoG/PrG), paracentral lobule (PCL)/supplementary motor area (SMA), and anterior cingulate cortex (ACC), and grey matter volume was increased in the left ACC in cLBP patients. PCL/SMA ALFF reliably discriminated cLBP patients from HCs in an independent cohort. cLBP patients showed increased ALFF in the insula, amygdala, hippocampal/parahippocampal gyrus, and thalamus and decreased ALFF in the default mode network (DMN) when their spontaneous low back pain intensity increased after the pain-exacerbating manoeuvre. Conclusions Brain low-frequency oscillations in the PCL, SMA, PoG, PrG, and ACC may be associated with the neuropathology of cLBP. Low-frequency oscillations in the insula, amygdala, hippocampal/parahippocampal gyrus, thalamus, and DMN are sensitive to manoeuvre-induced spontaneous back pain intensity changes.

Disease, drugs and the placebos used as comparators are inextricably linked in the methodology of the double-blind, randomized controlled trial. Nonetheless, pharmacogenomics, the study of how individuals respond to drugs based on genetic substrate, focuses primarily on the link between genes and drugs, while the link between genes and disease is often overlooked and the link between genes and placebos is largely ignored. Herein, we use the example of the enzyme catechol-O-methyltransferase to examine the hypothesis that genes can function as pharmacogenomic hubs across system-wide regulatory processes that, if perturbed in randomized controlled trials, can have primary and combinatorial effects on drug and placebo responses.

Accumulating evidence has shown that complicated brain systems are involved in the development and maintenance of chronic low back pain (cLBP), but the association between brain functional changes and clinical outcomes remains unclear. Here, we used resting-state functional magnetic resonance imaging (fMRI) and multivariate pattern analysis to identify abnormal functional connectivity (FC) between the default mode, sensorimotor, salience, and central executive brain networks in cLBP and tested whether abnormal FCs are related to pain and comorbid symptoms. Fifty cLBP patients and 44 matched healthy controls (HCs) underwent an fMRI scan, from which brain networks were identified by independent component analysis. Multivariate pattern analysis, graph theory approaches, and correlation analyses were applied to find abnormal FCs that were associated with clinical symptoms. Findings were validated on a second cohort of 30 cLBP patients and 30 matched HCs. Results showed that the medial prefrontal cortex/rostral anterior cingulate cortex had abnormal FCs with brain regions within the default mode network and with other brain networks in cLBP patients. These altered FCs were also correlated with pain duration, pain severity, and pain interference. Finally, we found that resting-state FC could discriminate cLBP patients from HCs with 91% accuracy in the first cohort and 78% accuracy in the validation cohort. Our findings suggest that the medial prefrontal cortex/rostral anterior cingulate cortex may be an important hub for linking the default mode network with the other 3 networks in cLBP patients. Elucidating the altered FCs and their association with clinical outcomes will enhance our understanding of the pathophysiology of cLBP and may facilitate the development of pain management approaches.

BackgroundVitamins are among the most frequently used supplements (48% of US adults). However, little is known about contributions of genetic variation to their efficacy and safety. Multiple pathways link catechol-O-methyltransferase (COMT) to the vitamin E supplement, alpha-tocopherol, and cancer.MethodsHere we determined if COMT exerted pharmacogenetic effects on cancer prevention in two randomized trials of alpha-tocopherol supplementation. Pharmacogenetic effects of common COMT rs4680 (val158met), which encodes a nonsynonymous valine-to-methionine substitution, were examined in the trial plus a 10-year post-trial follow-up (overall) period of The Women’s Genome Health Study (WGHS, N = 23 294), a 10-year alpha-tocopherol and aspirin trial with 10 years post-trial follow-up. Results were validated in a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC, N = 29 133). The primary outcome was total cancers. Rates of cancer types prevalent in women (colorectal, breast, lung, uterine, and lymphoma/leukemia) were also examined. All statistical tests were two-sided.ResultsRandom-effects meta-analysis of rs4680 genotype strata, in WGHS and ATBC overall periods, revealed differential alpha-tocopherol effects compared with placebo: met/met (hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.80 to 0.97; P = .01), val/met (HR = 0.99; 95% CI = 0.92 to 1.06; P = .74), and val/val (HR = 1.18; 95% CI = 1.06 to 1.31; P = .002) with a statistically significant COMT by alpha-tocopherol interaction (Pinteraction ConclusionPharmacogenetic analysis of COMT and cancer prevention in two large randomized trials revealed statistically significant COMT by alpha-tocopherol interaction, such that alpha-tocopherol was beneficial among rs4680 met-allele (28.0%), but not val-allele (22.8%) homozygotes. These effects indicate the need for additional studies of genetic variation as a determinant of the benefits and possible harms of over-the-counter supplements, like alpha-tocopherol, used for health promotion.

‘Differential placebo effects’ is the concept that different types of placebos (e.g. inert pill versus sham device) may yield different magnitudes of placebo effects. This issue has been pushed into the spotlight by recent clinical trials of new technologies reporting unexpectedly large placebo effects from sham devices/procedures needed to maintain blinding integrity. In this Neurology Grand Rounds, we use transcranial magnetic stimulation as a model to explore the principles and implications of differential placebo effects. We highlight emerging research on the neurobiology of placebo effects and analyze fundamental questions of measuring efficacy in contemporary medicine.

Harnessing placebo and nocebo effects has significant implications for research and medical practice. Placebo analgesia and nocebo hyperalgesia, the most well-studied placebo and nocebo effects, are thought to initiate from the dorsal lateral prefrontal cortex (DLPFC) and then trigger the brain's descending pain modulatory system and other pain regulation pathways. Combining repeated transcranial direct current stimulation (tDCS), an expectancy manipulation model, and functional MRI, we investigated the modulatory effects of anodal and cathodal tDCS at the right DLPFC on placebo analgesia and nocebo hyperalgesia using a randomized, double-blind and sham-controlled design. We found that compared with sham tDCS, active tDCS could 1) boost placebo and blunt nocebo effects and 2) modulate brain activity and connectivity associated with placebo analgesia and nocebo hyperalgesia. These results provide a basis for mechanistic manipulation of placebo and nocebo effects and may lead to improved clinical outcomes in medical practice.

Cognitive and evolutionary research has overwhelmingly focused on the powerful deities of large-scale societies, yet little work has examined the smaller gods of animist traditions. Here, in a study of the Mentawai water spirit Sikameinan (Siberut Island, Indonesia), we address three questions: (1) Are smaller gods believed to enforce cooperation, especially compared to bigger gods in larger-scale societies? (2) Do beliefs in these deities encourage people to engage in behavior that would otherwise be perceived as costly? and (3) Does ritual reinforce beliefs in these deities? Drawing on interview responses, data from healing ceremonies, and ethnographic observation, we show that Sikameinan is believed to punish people who violate meat-sharing norms and that people ‘attacked’ by Sikameinan pay shamans to conduct healing rituals. The public nature of rituals, involving prestigious individuals apologizing to Sikameinan for the patient’s stinginess, reinforce onlookers’ beliefs about Sikameinan. The most widely shared beliefs about Sikameinan are represented in rituals while beliefs not represented vary considerably, indicating that ritual may be potent for cultural transmission. These results suggest that moralizing supernatural punishers may be more common than suspected and that the trend in the cultural evolution of religion has been an expansion of deities’ scope, powers, and monitoring abilities.

This article is a summary of a talk presented in February 2019 at a conference on acupuncture sponsored by the National Institutes of Cancer (NCI) and the National Center for Complementary and Integrative Health (NCCIH) at the National of Institutes of Health (NIH). The article touches on the history of placebos in biomedicine and its absence in traditional East Asian Medicine. It then examines some of the predicaments of evaluating acupuncture's efficacy in relationship to placebo controls. Although acupuncture in randomized controlled trials (RCTs) generally demonstrate equivalence or even superiority to medical interventions or other nonpharmacologic therapies, acupuncture's ability to show superiority to placebo controls has been inconclusive, contradictory and, at best, modest. This article highlights the efforts of the German health insurance funds to evaluate acupuncture. Using a large meta-analysis, the article summaries acupuncture's effectiveness and efficacy. Subsequently, RCTs and meta-analyses testing the hypothesis that sham acupuncture, and other device placebos, have augmented placebo responses are described. It seems that acupuncture, and devices in general, have enhanced placebo responses. These findings may be relevant to designing and evaluating placebo-control acupuncture RCTs. Research into placebo acupuncture may also be helpful for other conditions where detection of intervention-placebo differences can be problematic. Further research is warranted.

It is commonly believed that blinding to treatment assignment is necessary for placebos to have an effect. However, placebos administered without concealment (ie, open-label placebos [OLPs]) have recently been shown to be effective in some conditions. This study had 2 objectives: first, to determine whether OLP treatment is superior to no-pill control (NPC) in irritable bowel syndrome (IBS) and, second, to compare the efficacy of OLP against double-blind placebo (DBP). In a 6-week, 3-arm, randomized clinical trial, participants were randomized in equal proportions to 3 arms: OLP, DBP, or NPC. Two hundred sixty-two adults (72.9% women), with a mean age of 42.0 (SD = 18.1) years, participated in the primary study. The mean improvement on the IBS Severity Scoring System from baseline to the 6-week end point was significantly greater in OLP compared with that in NPC (90.6 vs 52.3, P = 0.038). Open-label placebo and DBP did not differ significantly on IBS Severity Scoring System improvement (100.3 vs 90.6, P = 0.485). Standardized effect sizes were moderate for OLP vs NPC (d = 0.43) and small for OLP vs DBP (d = 0.10). Participants treated with OLP reported clinically meaningful improvements in IBS symptoms that were significantly greater than those on NPC. Open-label placebo and DBP had similar effects that did not differ significantly, suggesting that blinding may not be necessary for placebos to be effective and that OLP could play a role in the management of patients with refractory IBS.

Placebo effects have traditionally involved concealment or deception. However, recent evidence suggests that placebo effects can also be elicited when prescribed transparently as "open-label placebos" (OLPs), and that the pairing of an unconditioned stimulus (eg, opioid analgesic) with a conditioned stimulus (eg, placebo pill) can lead to the conditioned stimulus alone reducing pain. In this randomized control trial, we investigated whether combining conditioning with an OLP (COLP) in the immediate postoperative period could reduce daily opioid use and postsurgical pain among patients recovering from spine surgery. Patients were randomized to COLP or treatment as usual, with both groups receiving unrestricted access to a typical opioid-based postoperative analgesic regimen. The generalized estimating equations method was used to assess the treatment effect of COLP on daily opioid consumption and pain during postoperative period from postoperative day (POD) 1 to POD 17. Patients in the COLP group consumed approximately 30% less daily morphine milligram equivalents compared with patients in the treatment as usual group during POD 1 to 17 (-14.5 daily morphine milligram equivalents; 95% CI: [-26.8, -2.2]). Daily worst pain scores were also lower in the COLP group (-1.0 point on the 10-point scale; 95% CI: [-2.0, -0.1]), although a significant difference was not detected in average daily pain between the groups (-0.8 point; 95% CI: [-1.7, 0.2]). These findings suggest that COLP may serve as a potential adjuvant analgesic therapy to decrease opioid consumption in the early postoperative period, without increasing pain.

Key Points Question Are subjective patient-reported outcomes vs objective biomarkers associated with higher placebo responses in clinical trials? Findings In this cross-sectional study examining the placebo arms of 5 randomized clinical trials of rheumatoid arthritis including 788 patients, objective markers of inflammation and subjective pain ratings improved in a comparable clinically meaningful magnitude. Baseline values were associated with placebo response, suggesting that regression to the mean might dominate response to randomized placebo treatment. Meaning The findings of this study suggest that investigators may need to improve their understanding of natural history and baseline levels of outcomes because these factors can be important contributors to the response in placebo arms., Importance Large placebo responses in randomized clinical trials may keep effective medication from reaching the market. Primary outcome measures of clinical trials have shifted from patient-reported to objective outcomes, partly because response to randomized placebo treatment is thought to be greater in subjective compared with objective outcomes. However, a direct comparison of placebo response in subjective and objective outcomes in the same patient population is missing. Objective To assess whether subjective patient-reported (pain severity) and objective inflammation (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]) outcomes differ in placebo response. Design, Setting, and Participants The placebo arms of 5 double-blind, randomized, placebo-controlled clinical trials were included in this cross-sectional study. These trials were conducted internationally for 24 weeks or longer between 2005 and 2009. All patients with rheumatoid arthritis randomized to placebo (N = 788) were included. Analysis of data from these trials was conducted from March 27 to December 31, 2019. Intervention Placebo injection. Main Outcomes and Measures The difference (with 95% CIs) from baseline at week 12 and week 24 on a 0- to 100-mm visual analog scale to evaluate the severity of pain, CRP level, and ESR. Results Of the 788 patients included in the analysis, 644 were women (82%); mean (SD) age was 51 (13) years. There was a statistically significant decrease in patient-reported pain intensity (week 12: −14 mm; 95% CI, −12 to −16 mm and week 24: −20 mm; 95% CI, −16 to −22 mm). Similarly, significant decreases were noted in the CRP level (week 12: −0.51 mg/dL; 95% CI, −0.47 to −0.56 mg/dL and week 24: −1.16 mg/dL; 95% CI, −1.03 to −1.30 mg/dL) and ESR (week 12: −11 mm/h; 95% CI, −10 to 12 mm/h and week 24: −25 mm/h; 95% CI, −12 to −26 mm/h) (all P, This cross-sectional study examines subjective vs objective responses to placebo administration in clinical trials on patients with rheumatoid arthritis.

Purpose Ongoing symptoms and impairments in quality of life (QOL) among breast cancer survivors remain a significant problem. We tested the feasibility and acceptability of a manualized Ayurvedic nutrition and lifestyle intervention for breast cancer survivors. Methods Eligible participants had Stage I–III breast cancer, underwent treatment within the past year that included chemotherapy, and were without active disease. The 4-month individualized Ayurvedic intervention included counseling on nutrition, lifestyle, yoga, and marma (like acupressure) during 8 one-on-one visits with an Ayurvedic practitioner. Feasibility and acceptability were the primary outcomes. QOL (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ C30]) and symptoms—sleep disturbance (General Sleep Disturbance Scale [GSDS]), fatigue (Lee Fatigue Scale [LFS]), depressive symptoms (Center for Epidemiological Studies—Depression Scale [CES-D]), anxiety (Spielberger State-Trait Anxiety Inventory [STAI-S, STAI-T]), and stress (Perceived Stress Scale [PSS])—were measured prior to, at midpoint, and at the end of the 4-month intervention. Effect sizes (Cohen’s d) were calculated along with paired t tests comparing baseline to end of month 4 time points. Mixed effects models were used for repeated measures analyses. Results Participants ( n = 32) had a mean age of 48 years ( SD = 10). Retention at the end of the intervention was 84%. Among those who completed the intervention ( n = 27), adherence was high (99.5% of visits with practitioners attended). Large improvements were seen in QLQ-C30 emotional functioning ( d = 0.84, P Conclusion This 4-month Ayurvedic whole-systems multimodal nutrition and lifestyle intervention was feasible and acceptable for breast cancer survivors. Promise of clinical benefit was seen in terms of improvements in symptoms and QOL that warrants further investigation.

Thalamocortical dysrhythmia is a key pathology of chronic neuropathic pain, but few studies have investigated thalamocortical networks in chronic low back pain (cLBP) given its non-specific etiology and complexity. Using fMRI, we propose an analytical pipeline to identify abnormal thalamocortical network dynamics in cLBP patients and validate the findings in two independent cohorts. We first identify two reoccurring dynamic connectivity states and their associations with chronic and temporary pain. Further analyses show that cLBP patients have abnormal connectivity between the ventral lateral/posterolateral nucleus (VL/VPL) and postcentral gyrus (PoCG) and between the dorsal/ventral medial nucleus and insula in the less frequent connectivity state, and temporary pain exacerbation alters connectivity between the VL/VPL and PoCG and the default mode network in the more frequent connectivity state. These results extend current findings on thalamocortical dysfunction and dysrhythmia in chronic pain and demonstrate that cLBP pathophysiology and clinical pain intensity are associated with distinct thalamocortical network dynamics., Thalamocortical dysrhythmia is a key pathology of chronic pain. Here, the authors propose an analytical pipeline to study dynamic fMRI brain networks and demonstrate that chronic low back pain pathophysiology and clinical pain intensity are associated with distinct thalamocortical network dynamics.

Given the complexity of pain management in rehabilitation settings, pharmaco-behavioral interventions can capitalize on the self-modulatory process to enhance the effects of a drug-based intervention., Introduction: Opioid consumption for those in comprehensive inpatient rehabilitation units is high because of the complexity of their injuries. Notably, pain in rehabilitation leads to worsened clinical outcomes because of maladaptive behaviors and poor engagement during therapies. It is critical to developing evidence-based pharmacobehavioral interventions. Based on principles of classical conditioning, conditioning open-label placebo (COLP) is a promising approach for reducing opioid use in comprehensive inpatient rehabilitation, and this technique takes advantage of the possibility of association learning and opioid pharmacology to promote evoked placebo-driven analgesia. Objectives: In this brief report, we evaluate the feasibility of COLP as a pharmacobehavioral intervention to decrease total opioid consumption in patients with pain hospitalized at Spaulding Rehabilitation Hospital. Methods: Inpatients with spinal cord injury and polytrauma (n = 20) with moderate to severe pain were randomized to receive COLP (n = 10) or treatment-as-usual for 6 consecutive days. Opioid utilization was measured by morphine equivalents using the morphine equivalent dose conversion; pain severity was assessed using the numerical visual analog scale. Results: Conditioning open-label placebo significantly reduced total opioid consumption by the end of the intervention period (P ≤ 0.001). Pain reduction was also significant for the COLP group (P = 0.005), whereas the treatment-as-usual group demonstrated a trend towards pain reduction (P = 0.05). Conclusions: This study presents the first data in the use of a pharmacobehavioral intervention that capitalize on the benefits of open-label placebo and classical drug conditioning for opioid dose reduction in a population with moderate to severe pain exposed to intensive inpatient rehabilitation.

Despite their ubiquitous presence, placebos and placebo effects retain an ambiguous and unsettling presence in biomedicine. Specifically focused on chronic pain, this review examines the effect of placebo treatment under three distinct frameworks: double blind, deception, and open label honestly prescribed. These specific conditions do not necessarily differentially modify placebo outcomes. Psychological, clinical, and neurological theories of placebo effects are scrutinized. In chronic pain, conscious expectation does not reliably predict placebo effects. A supportive patient-physician relationship may enhance placebo effects. This review highlights “predictive coding” and “bayesian brain” as emerging models derived from computational neurobiology that offer a unified framework to explain the heterogeneous evidence on placebos. These models invert the dogma of the brain as a stimulus driven organ to one in which perception relies heavily on learnt, top down, cortical predictions to infer the source of incoming sensory data. In predictive coding/bayesian brain, both chronic pain (significantly modulated by central sensitization) and its alleviation with placebo treatment are explicated as centrally encoded, mostly non-conscious, bayesian biases. The review then evaluates seven ways in which placebos are used in clinical practice and research and their bioethical implications. In this way, it shows that placebo effects are evidence based, clinically relevant, and potentially ethical tools for relieving chronic pain.