Are all placebo effects equal? Placebo pills, sham acupuncture, cue conditioning and their association

Electroacupuncture treatment improves postoperative ileus by inhibiting the Th1 cell-mediated inflammatory response through the vagus nerve

BACKGROUND

Electroacupuncture (EA) has been reported to improve intestinal motility in mice with postoperative ileus (POI). Previous studies, however, have yielded heterogeneous results regarding the effect of EA on POI.

METHODS

Herein, a POI mouse model was constructed by intestinal manipulation. To evaluate the effect of EA treatment on colonic transit, the levels of inflammatory markers (macrophage inflammatory protein (MIP)-1α, interleukin (IL)-1β, IL-6, monocyte chemotactic protein (MCP)-1 and intercellular adhesion molecule (ICAM)-1) were detected by enzyme-linked immunosorbent assay (ELISA); immune cell infiltration was detected by immunohistochemical staining of myeloperoxidase (MPO), ectodysplasin (ED)-1 and ED-2, and the percentage of CD4+ interferon (IFN)-γ+ Th1 cells and IFN-γ secretion levels were determined. Activated Th1 cells and pentoxifylline, a cell differentiation inhibitor, were used to assess the role of Th1 cells in EA treatment of POI. Neostigmine administration and unilateral vagotomy were performed to confirm whether the effects of EA treatment on Th1 cells were mediated by the vagus nerve (VN).

RESULTS

The results revealed that EA treatment at ST36 improved POI, as indicated by a decreased level of inflammatory-related markers and immune cell infiltration and shortened colonic transit time. The activated Th1 cells abolished the effects of EA treatment on POI. The effects of EA treatment on POI were enhanced by stimulation of the VN along with a decreased level of Th1 cells, but these effects were abolished by vagotomy along with an increased percentage of Th1 cells; this result indicates that the VN mediates the role of Th1 cells in the effects of EA treatment of POI.

CONCLUSION

Our findings showed that the effects of EA treatment of POI were mainly mediated by Th1 cells through the stimulation of the VN and inhibition of the inflammatory response.

Thalamocortical Mechanisms Underlying Real and Imagined Acupuncture

Both acupuncture and imagery have shown potential for chronic pain management. However, the mechanisms underlying their analgesic effects remain unclear. This study aims to explore the thalamocortical mechanisms underlying acupuncture and video-guided acupuncture imagery treatment (VGAIT), a combination of acupuncture and guided imagery, using the resting-state functional connectivity (rsFC) of three thalamic subdivisions-the ventral posterolateral thalamus (VPL), mediodorsal thalamus (MD), and motor thalamus subregion (Mthal)-associated with somatosensory, limbic, and motor circuity. Twenty-seven healthy individuals participated in a within-subject randomized crossover design study. Results showed that compared to sham acupuncture, real acupuncture altered the rsFC between the thalamus and default mode network (DMN) (i.e., mPFC, PCC, and precuneus), as well as the prefrontal and somatosensory cortex (SI/SII). Compared to the VGAIT control, VGAIT demonstrated greater rsFC between the thalamus and key nodes within the interoceptive network (i.e., anterior insula, ACC, PFC, and SI/SII), as well as the motor and sensory cortices (i.e., M1, SMA, and temporal/occipital cortices). Furthermore, compared to real acupuncture, VGAIT demonstrated increased rsFC between the thalamus (VPL/MD/Mthal) and task-positive network (TPN). Further correlations between differences in rsFC and changes in the heat or pressure pain threshold were also observed. These findings suggest that both acupuncture- and VGAIT-induced analgesia are associated with thalamocortical networks. Elucidating the underlying mechanism of VGAIT and acupuncture may facilitate their development, particularly VGAIT, which may be used as a potential remote-delivered pain management approach.

Placebo effects on cutaneous pain and itch: a systematic review and meta-analysis of experimental results and methodology

ABSTRACT

Placebo effects, positive treatment outcomes that go beyond treatment processes, can alter sensations through learning mechanisms. Understanding how methodological factors contribute to the magnitude of placebo effects will help define the mechanisms by which these effects occur. We conducted a systematic review and meta-analysis of experimental placebo studies in cutaneous pain and itch in healthy samples, focused on how differences in methodology contribute to the resulting placebo effect magnitude. We conducted meta-analyses by learning mechanism and sensation, namely, for classical conditioning with verbal suggestion, verbal suggestion alone, and observational learning, separately for pain and itch. We conducted subgroup analyses and meta-regression on the type of sensory stimuli, placebo treatment, number of acquisition and evocation trials, differences in calibrated intensities for placebo and control stimuli during acquisition, age, and sex. We replicated findings showing that a combination of classical conditioning with verbal suggestion induced larger placebo effects on pain ( k = 68, g = 0 . 59) than verbal suggestion alone ( k = 39, g = 0.38) and found a smaller effect for itch with verbal suggestion alone ( k = 7, g = 0.14). Using sham electrodes as placebo treatments corresponded with larger placebo effects on pain than when topical gels were used. Other methodological and demographic factors did not significantly affect placebo magnitudes. Placebo effects on pain and itch reliably occur in experimental settings with varied methods, and conditioning with verbal suggestion produced the strongest effects. Although methods may shape the placebo effect to some extent, these effects appear robust overall, and their underlying learning mechanisms may be harnessed for applications outside the laboratory.

Patient reported outcomes and recruitment rates following the introduction of principled patient information leaflets (PrinciPILs): Protocol for a meta-analysis

Background

The way potential benefits and harms of trial interventions are shared within patient information leaflets (PILs) varies widely and may cause unnecessary harms ("nocebo effects"). The aim of this meta-analysis will be to evaluate the influence on recruitment rates and early effects on patient reported adverse events of principled patient information leaflets (PrinciPILs) compared with standard PILs.

Methods

Eligible studies will include those that report the effects on recruitment and patient reported adverse events of PrinciPILs compared to standard PILs. We will include in this meta-analysis all the standard PILs in studies within trials (SWATs) of PrinciPILs that were developed as part of the Medical Research Council (MRC) funded PrinciPIL project. By publishing this as a living meta-analysis, we will allow the meta-analysis to be updated with future SWATs of PrinciPILs. We will use the Cochrane Risk of Bias tool to evaluate the risk of bias for each outcome. We will report the total number of studies and participants analysed and the characteristics of included studies (including details of intervention, comparators, outcomes). For dichotomous data, we will calculate the risk difference and the risk ratio (RR) and 95% confidence intervals (CIs). For continuous outcomes we will use weighted mean differences with 95% CIs or standardized mean differences with 95% CIs. We will investigate heterogeneity by visually inspecting the forest plot and by considering the I 2 test result. We will assess the certainty warranted for each outcome using the Grading of Recommendations Assessment Development and Evaluation (GRADE). Ethics approval is not applicable since no original data will be collected. The results will be disseminated through peer-reviewed publication and conference presentations.

Discussion

We will discuss the limitations of the meta-analysis including study risk of bias, inconsistency, heterogeneity, and imprecision. A general interpretation of the results and important implications will be provided.

Investigating the hypoalgesic effects of spinal manipulative therapy using hidden pain conditioning and positive expectation in patients with chronic low back pain: protocol for a randomised controlled trial

INTRODUCTION

Placebo effects are responses capable of modulating pain and influencing treatment response. Two mechanisms are commonly related to placebo effects: expectations and conditioning. However, the research in this field is focused on laboratory studies with healthy participants. This study aims to identify whether a conditioning procedure with positive induced expectations about spinal manipulative therapy (SMT) will result in greater hypoalgesic effects in adults with chronic low back pain (CLBP) in a clinical trial design.

METHODS AND ANALYSIS

This trial will enrol 264 patients with non-specific CLBP, aged 18-60 years. Patients will undergo a calibration test to determine the thermal pain threshold for the hidden pain conditioning procedure. Afterward, they will be randomised to one of the three groups: hidden pain conditioning with positive induced expectations-group one (G1); positive expectations-group two (G2) and neutral expectations-group three (G3). Patients will receive instructions to manipulate the expectations. The pretreatment heat pain test will be performed before the SMT and after the intervention patients will undergo again the heat pain intensity test. However, only patients in G1 will receive hidden pain conditioning to reinforce the association between SMT and pain intensity reduction. All patients will undergo five sessions of SMT. The outcomes will be assessed immediately after the last session and at the 6 weeks and 3-month follow-ups. All statistical analyses will be conducted following intention-to-treat principles, and the treatment effects will be determined with linear mixed models.

ETHICS AND DISSEMINATION

The Federal University of São Carlos approved this research (Process n° 52359521.1.0000.5504). All participants will give written informed consent. Dissemination of the results will include publications in peer-reviewed journals and presentations at conferences. If positive expectations and classical conditioning improve outcomes, it may support the administration of such intervention.

TRIAL REGISTRATION NUMBER

NCT05202704.

Clinical Efficacy and Immune Effects of Acupuncture in Patients with Comorbid Chronic Pain and Major Depression Disorder: A Double-Blinded, Randomized Controlled Crossover Study

BACKGROUND

Depression and pain are highly comorbid and share biological mechanisms. Acupuncture is commonly used to manage both pain and depression, but the choice of acupoints for specific disorders differs. This study aimed to investigate whether specific acupuncture intervention on pain- and depression-acupoints would have specific efficacy and immune effects in patients with comorbid chronic pain and major depressive disorder (MDD).

METHODS

We performed a subject- and assessor-blinded, crossover, and randomized controlled clinical trial of depression- and pain-specific acupuncture intervention and measured clinical responses and proinflammatory cytokines in patients with comorbid chronic pain and MDD. Specific acupoints for pain and depression were used in random order with a washout interval. Forty-seven patients were enrolled and randomly assigned to two groups: (1) the depression-pain group (23 patients who were treated with depression-specific acupoints and then the pain-specific acupoints after the washout) and (2) pain-depression group (24 patients with the reverse order).

RESULTS

The pain-specific acupoints for pain did not reduce Brief Pain Inventory scores to a significantly greater degree (-0.97 ± 1.69) than the depression-specific acupoints (-0.28 ± 1.88); likewise, the depression-specific acupoints did not significantly ameliorate Hamilton Depression Rating Scale (-4.59 ± 6.02) than the pain-specific acupoints (-6.69 ± 6.61). The pain-specific acupoints improved Beck Depression Inventory-Second Edition (-6.74 ± 9.76) even better than the depression-specific acupoints (-1.92 ± 10.74). The depression-specific acupoints did not significantly decrease the depression-related interleukin (IL)-6 level (-1.24 ± 6.67) than the pain-specific acupoints (-0.60 ± 4.36). The changed levels of IL-1β, tumor necrosis factor (TNF)-α between the depression-specific acupoints (-37.41 ± 194.49; -12.53 ± 54.68) and the pain-specific acupoints (-15.46 ± 87.56; -7.28 ± 27.86) could not reach significantly different, too.

CONCLUSION

This study rejected our hypothesis that the pain-specific acupoints might produce superior analgesic effects than the depression-specific acupoints and vice versa. The cytokine results might imply that pain and depression share common biological mechanisms. (trial registration: https://www.

CLINICALTRIALS

gov: NCT03328819).

Modulation effects of different treatments on periaqueductal gray resting state functional connectivity in knee osteoarthritis knee pain patients

BACKGROUND

The analgesic effect of acupuncture is widely recognized, but the mechanical characteristics of acupuncture for pain relief, compared to non-steroidal anti-inflammatory (NSAIDs) and placebo medication, remain unknown.

AIMS

To compare the modulation effects of acupuncture treatment with NSAIDs and placebo medication on descending pain modulation system (DPMS) in knee osteoarthritis (KOA) patients.

METHODS

This study recruited 180 KOA patients with knee pain and 41 healthy controls (HCs). Individuals with KOA knee pain were divided randomly into groups of verum acupuncture (VA), sham acupuncture (SA), celecoxib (SC), placebo (PB), and waiting list (WT), with 36 patients in each group. VA and SA groups included ten sessions of puncturing acupoints or puncturing non-acupoints acupuncture treatment for two successive weeks. Celecoxib capsules were continuously given orally to patients in the SC group at a dosage of 200 mg daily for 2 weeks. In the PB group, patients received a placebo capsule once a day for 2 weeks at the same dosage as celecoxib capsules. In the WL group, patients did not receive any treatment. Patients underwent a resting-state BOLD-fMRI scan pre- and post-receiving the therapy, whereas HCs only underwent a baseline scan. Seed (ventrolateral periaqueductal gray, vlPAG, a key node in DPMS) based resting-state functional connectivity (rs-FC) was applied in the data analysis.

RESULTS

All groups demonstrated improved knee pain scores relative to the initial state. There was no statistical difference between the VA and SA groups in all clinical outcomes, and vlPAG rs-FC alterations. KOA knee pain individuals reported higher vlPAG rs-FC in the bilateral thalamus than HCs. KOA knee pain patients in the acupuncture group (verum + sham, AG) exhibited increased vlPAG rs-FC with the right dorsolateral prefrontal cortex (DLPFC) and the right angular, which is associated with knee pain improvement. In contrast with the SC and PB group, the AG exhibited significantly increased vlPAG rs-FC with the right DLPFC and angular. Contrary to the WT group, the AG showed greater vlPAG rs-FC with the right DLPFC and precuneus.

CONCLUSIONS

Acupuncture treatment, celecoxib, and placebo medication have different modulation effects on vlPAG DPMS in KOA knee pain patients. Acupuncture could modulate vlPAG rs-FC with brain regions associated with cognitive control, attention, and reappraisal for knee pain relief in KOA patients, compared with celecoxib and placebo medication.

Delivery of acupuncture in clinical trials: Research acupuncturists’ perspectives

Delivery of acupuncture in the setting of a clinical trial is a unique practice that diverges significantly from the delivery of acupuncture in a real-world clinical setting. Research acupuncturists, particularly those trained in traditional Chinese medicine (TCM), are often required to set aside valued precepts of traditional care, including diagnosing imbalances, individualizing treatment, and forging a therapeutic relationship with patients. TCM-trained acupuncturists express mixed feelings about participating in clinical trials. Many are eager to play a vital role in the advancement of acupuncture science and appreciate the need for strict protocol adherence to minimize bias. However, the acupuncturist(s) may also have concerns about clinical trial methodology, including but not limited to the delivery of a control condition, e.g., sham acupuncture. Investigators should anticipate certain questions and even a level of resistance to the requirements of research among acupuncturists and be prepared to address them. This manuscript presents a brief review of the subjective experience of the research acupuncturist within the available scientific literature as it pertains to the delivery of active and sham clinical research protocols. Our goals are to better understand the perspectives of acupuncturists who may participate in clinical research, so that their concerns may be addressed in study design and methodology. To that end, we suggest the creation of a novel training program specifically for clinical trial acupuncturists, intended for qualified TCM- and Western-trained practitioners, that would help to standardize the research acupuncturist's role and help to strengthen the design and execution of acupuncture studies.

Current status of neuroimaging research on the effects of acupuncture: a bibliometric and visual analyses

OBJECTIVE

To conduct an inductive analysis of neuroimaging studies following the global popularity surrounding the effects of acupuncture.

METHODS

The relevant works of literature on acupuncture effects-related neuroimaging studies were retrieved from the web of science core collection database from the date of its establishment to 2022. Bibexcel software was used to extract information, such as article numbers, countries, journals, agencies, funding sources and keywords. The VOSviewer software's co-occurrence and clustering module was used for the co-occurrence and cluster analysis of collaborative networks and high frequency keywords, such as authors, institutions and countries.

RESULTS

Neuroimaging research on the effects of acupuncture began in the 1960 s and has since received the extensive attention of scholars. China, The United States and South Korea conduct more neuroimaging research on the effects of acupuncture than other countries. Academic journals such as Evidence-Based Complementary and Alternative Medicine, Journal of Alternative and Complementary Medicine, Neural Regeneration Research and Acupuncture in Medicine have published the highest number of acupuncture-related neuroimaging articles. Moreover, cluster analysis differentiates high-frequency keywords into six clusters. Furthermore, the use of the keyword 'density atlas' reveals that neuroimaging research on the effects of acupuncture surrounding pain and neurofunctional rehabilitation is currently the research focus.

CONCLUSIONS

This bibliometric study identifies six important research hot spots: Static brain functional connectivity analysis of acupuncture analgesic effects, key theories on the scientific problems of acupuncture, acupuncture analgesic effect of the placebo effect, the neuroimaging of acupoint ST-36, the value of acupuncture in regulating the autonomic nerves and acupuncture therapy as complementary medicine.

Treatment of acute exacerbations of chronic obstructive pulmonary disease with acupuncture during hospitalization: a three-arm double-blinded randomized sham-controlled trial

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a healthcare burden. Acupuncture improves dyspnea in patients with chronic obstructive pulmonary disease (COPD) but, to the best of our knowledge, has not been tested in AECOPD. Here, we evaluated the efficacy and safety of true acupuncture added to standard of care (SOC), as compared with both sham procedure plus SOC and SOC only, for the treatment of AECOPD among inpatients.

METHODS

This double-blinded randomized sham-controlled trial was set in a tertiary hospital in Israel. Patients with a clinical diagnosis of AECOPD were assigned to true acupuncture with SOC, sham procedure with SOC or SOC only. The primary outcome was dyspnea improvement as measured daily by the validated modified Borg (mBorg) scale. Secondary outcomes included improvement of other patient-reported outcomes and physiologic features, as well as duration of hospitalization and treatment failure. Acupuncture-related side effects were evaluated by the validated Acup-AE questionnaire.

RESULTS

Seventy-two patients were randomized: 26 to acupuncture treatment, 24 to sham and 22 to SOC only arms. Baseline characteristics were similar in the three groups. A statistically significant difference in dyspnea intensity was found from the first day of evaluation after treatment (p = 0.014) until day 3 after treatment. Similar results were found for sputum production, but no statistical significance was found when comparing physiologic features between the three arms. Acupuncture was not associated with adverse events.

CONCLUSION

Acupuncture seems to be efficacious in the treatment of AECOPD among inpatients hospitalized in internal medicine departments.

TRIAL REGISTRATION NUMBER

NCT03398213 (ClinicalTrials.gov).

Who are the placebo responders? A cross-sectional cohort study for psychological determinants

ABSTRACT

A number of studies have demonstrated substantial individual differences in placebo effects. We aimed to identify individual psychological factors that potentially predicted the magnitude of placebo hypoalgesia and individual responsiveness. The Research Domain Criteria framework and a classical conditioning with suggestions paradigm were adopted as experimental models to study placebo phenotypes in a cohort of 397 chronic pain participants with a primary diagnosis of temporomandibular disorder (TMD) and 397 healthy control (HC) participants. The magnitude of placebo hypoalgesia was operationalized as the average difference in pain ratings between the placebo and control conditions. The individual placebo responsiveness was identified as the status of placebo responders and nonresponders based on a permutation test. We observed significant placebo effects in both TMD and HC participants. A greater level of emotional distress was a significant predictor of smaller magnitude (slope b = -0.07) and slower extinction rate (slope b = 0.51) of placebo effects in both TMD and HC participants. Greater reward seeking was linked to greater postconditioning expectations (ie, reinforced expectations) in TMD (slope b = 0.16), but there was no such a prediction in HC participants. These findings highlight that negative valence systems might play a role in impairing placebo effects, with a larger impact in chronic pain participants than in healthy participants, suggesting that individuals reporting emotional distress and maladaptive cognitive appraisals of pain may benefit less from placebo effects.

Psycho-Neuro-Endocrine-Immunological Basis of the Placebo Effect: Potential Applications beyond Pain Therapy

The placebo effect can be defined as the improvement of symptoms in a patient after the administration of an innocuous substance in a context that induces expectations regarding its effects. During recent years, it has been discovered that the placebo response not only has neurobiological functions on analgesia, but that it is also capable of generating effects on the immune and endocrine systems. The possible integration of changes in different systems of the organism could favor the well-being of the individuals and go hand in hand with conventional treatment for multiple diseases. In this sense, classic conditioning and setting expectations stand out as psychological mechanisms implicated in the placebo effect. Recent advances in neuroimaging studies suggest a relationship between the placebo response and the opioid, cannabinoid, and monoaminergic systems. Likewise, a possible immune response conditioned by the placebo effect has been reported. There is evidence of immune suppression conditioned through the insular cortex and the amygdala, with noradrenalin as the responsible neurotransmitter. Finally, a conditioned response in the secretion of different hormones has been determined in different studies; however, the molecular mechanisms involved are not entirely known. Beyond studies about its mechanism of action, the placebo effect has proved to be useful in the clinical setting with promising results in the management of neurological, psychiatric, and immunologic disorders. However, more research is needed to better characterize its potential use. This review integrates current knowledge about the psycho-neuro-endocrine-immune basis of the placebo effect and its possible clinical applications.

Open-Label Placebo Treatment for Experimental Pain: A Randomized-Controlled Trial with Placebo Acupuncture and Placebo Pills

Objective: An open-label placebo (OLP) is a placebo treatment in which the patient is aware that the treatment is a placebo. OLPs are considered effective for reducing pain, and previous studies have shown a stronger placebo effect for placebo acupuncture than for placebo pills. In this study, the authors compared the analgesic effects of OLP pills, OLP acupuncture, and a no treatment condition in healthy participants, and then examined the factors contributing to the OLP effect. Design: Randomized controlled crossover trial. Settings/Location: College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea. Subjects: 34 healthy participants. Intervention: Participants received three different treatments ("OLP-pill," "OLP-acupuncture," and "no treatment") on three separate days in random order. Outcome Measurements: Before and after the treatment, heat pain stimuli were applied to the participants' hands, and pain tolerance, intensity, and unpleasantness were measured using a visual analog scale (range, 0-10). Results: Data of 31 participants were included in the analysis. The authors found significant analgesic effects of the placebo pill and placebo acupuncture in the OLP condition. Regression analyses revealed that expectations regarding treatment and practitioner identity influenced the analgesic effects of OLP acupuncture. There was no adverse event. Conclusions: Expectations regarding treatment and practitioner identity influenced the analgesic effect of placebo acupuncture without deception. These findings provide new information regarding the cognitive factors underlying pharmacologic and nonpharmacologic treatments. Clinical Trial Registration Number: KCT0004928.

Direct Verbal Suggestibility as a Predictor of Placebo Hypoalgesia Responsiveness

OBJECTIVE

Reliably identifying good placebo responders has pronounced implications for basic research on, and clinical applications of, the placebo response. Multiple studies point to direct verbal suggestibility as a potentially valuable predictor of individual differences in placebo responsiveness, but previous research has produced conflicting results on this association.

METHODS

In two double-blind studies, we examined whether behavioral direct verbal suggestibility measures involving a correction for compliance would be associated with individual differences in responsiveness to conditioned and unconditioned placebo hypoalgesia using an established placebo analgesia paradigm. In study 1 (n = 57; mean [standard deviation] age = 23.7 [8.1] years; 77% women), we used behavioral hypnotic suggestibility as a predictor of placebo hypoalgesia induced through conditioning and verbal suggestion, whereas in study 2 (n = 78; mean [standard deviation] = 26.1 [7.4] years; 65% women), we measured nonhypnotic suggestibility and placebo hypoalgesia induced through verbal suggestion without conditioning.

RESULTS

In study 1, the placebo hypoalgesia procedure yielded a moderate placebo response (g = 0.63 [95% confidence interval = 0.32 to 0.97]), but the response magnitude did not significantly correlate with hypnotic suggestibility (rs = 0.11 [-0.17 to 0.37]). In study 2, the placebo procedure did not yield a significant placebo response across the full sample (g = 0.11 [-0.11 to 0.33]), but the magnitude of individual placebo responsiveness significantly correlated with nonhypnotic suggestibility (rs = 0.27 [0.03 to 0.48]).

CONCLUSIONS

These results suggest that the extent to which direct verbal suggestibility captures variability in placebo responsiveness depends on the use of conditioning and highlights the utility of suggestibility as a potential contributing factor to placebo responding when placebo hypoalgesia is induced through verbal suggestions.

A social affective neuroscience lens on placebo analgesia

Pain is a fundamental experience that promotes survival. In humans, pain stands at the intersection of multiple health crises: chronic pain, the opioid epidemic, and health disparities. The study of placebo analgesia highlights how social, cognitive, and affective processes can directly shape pain, and identifies potential paths for mitigating these crises. This review examines recent progress in the study of placebo analgesia through affective science. It focuses on how placebo effects are shaped by expectations, affect, and the social context surrounding treatment, and discusses neurobiological mechanisms of placebo, highlighting unanswered questions and implications for health. Collaborations between clinicians and social and affective scientists can address outstanding questions and leverage placebo to reduce pain and improve human health.

Regulatory Effects of Acupuncture on Emotional Disorders in Patients With Menstrual Migraine Without Aura: A Resting-State fMRI Study

Background: Menstrual migraine without aura (MMoA) refers to a specific type of migraine that is associated with the female ovarian cycle. It is particularly serious and has brought huge life pressure and mental burden to female patients. Acupuncture has been commonly used to prevent migraines and relieve concomitant emotional disorders; however, the physiological mechanism underlying this intervention remains unclear. This study aimed to use resting-state functional magnetic resonance imaging (rsfMRI) to investigate whether acupuncture can modulate brain function and if the potential influence on brain activity correlates with improving emotional symptoms in MMoA patients. Methods: Overall, 44 patients were randomly divided into a true acupuncture (TA) group and the sham acupuncture (SA) group. Patients underwent rsfMRI before and after 3-month treatment, the amplitude of low-frequency fuctuations (ALFF) and regional homogeneity (ReHo) in rsfMRI were calculated. Zung self-rating anxiety scale (SAS), Zung self-rating depression scale (SDS), frequency of migraine attacks, visual analog scale, and intensity of the migraine were used for evaluate the clinical effect. The clinical changes of variables were also used to further assess the correlation with brain activity in MMoA patients. Results: After acupuncture treatment, the emotional symptoms of both groups of patients improved, and the clinical symptoms of migraine were alleviated. The major finding of our study was that patients with MMoA showed lower ALFF value in the left anterior cingulate and the value was positively correlated with the decreases in the SAS and SDS scores. In the SA group, common brain regions responded both in ALFF and regional homogeneity values mainly in the insula, and no significant correlations were observed between brain regions and clinical variables. Conclusions: These results indicated that both two acupuncture treatments were helpful in treating migraine and could improve emotion symptoms. TA had a relatively better effect in reducing the frequency of migraine attack than SA. The two therapies have different modulation effects as TA regulates emotional disorders by modulating the frontal-limbic regions, and SA may modulate pain perception through the placebo effect on insula and by indirectly regulating emotional disorders. These findings provided evidence that acupuncture is a complementary and alternative therapy to relieve clinical symptoms in female patients with migraines and could help enhance clinical diagnosis and treatment. Clinical Trial Registration: [http://www.chictr.org.cn/index.aspx], identifier [ChiCTR-IOR-15006648. Registered 23 June 2015].

Systematic Review with Meta-Analysis: Effectiveness and Safety of Acupuncture as Adjuvant Therapy for Side Effects Management in Drug Therapy-Receiving Breast Cancer Patients

OBJECTIVE

To investigate the potential benefits and safety of acupuncture on managing side effects induced by drug therapies in patients with breast cancer using a PRISMA standard systematic review and meta-analysis.

METHODS

Published randomised controlled trials from nine databases in English and Chinese language were searched. Trials with a real acupuncture treatment group and a control group with sham acupuncture, no treatment, or waitlist control were included. The primary outcome of this study was the therapeutic effects on five symptoms induced by drug therapies, including gastrointestinal disorder, neuropathy, arthralgia, joint symptoms, and cognitive impairment. The quality of life was assessed as a secondary outcome. The risk of bias of each study was analysed according to the Cochrane Handbook.

RESULTS

Sixteen randomised controlled trials with 1189 participants were included in the meta-analysis. The primary outcome and all subgroup analyses showed statistically significant improvements in the management of side effects by real acupuncture. The quality of life of patients has enhanced during the treatment.

CONCLUSION

Although the number of publications is limited, a clear preliminary conclusion could be drawn by the meta-analysis, suggesting the beneficial adjuvant role of acupuncture in patients with breast cancer who receive drug therapies. No serious adverse events were observed from all the RCTs, and the safety of acupuncture is ascertained. More standardised and sophisticated large-scale randomised controlled trials are needed to evaluate the findings further.

Modulatory Effects of Actual and Imagined Acupuncture on the Functional Connectivity of the Periaqueductal Gray and Ventral Tegmental Area

OBJECTIVE

Both acupuncture and guided imagery hold promise for treating pain. The mechanisms underlying these alternative interventions remain unclear. The reported study aimed to comparatively investigate the modulation effect of actual and imagined acupuncture on the functional connectivity of descending pain modulation system and reward network.

METHODS

Twenty-four healthy participants (mean [standard error], 25.21 [0.77] years of age; 66.67% female) completed a crossover study that included five sessions, a training session and four intervention sessions administered in randomized order. We investigated the modulation effect of real acupuncture, sham acupuncture, video-guided acupuncture imagery treatment (VGAIT) and VGAIT control on the resting-state functional connectivity (rsFC) of periaqueductal gray (PAG) and ventral tegmental area (VTA). These are key regions of the descending pain modulatory system and dopaminergic reward system, respectively.

RESULTS

Compared with sham acupuncture, real acupuncture produced decreased PAG-precuneus (Pcu) rsFC and increased VTA-amygdala/hippocampus rsFC. Heat pain threshold changes applied on the contralateral forearm were significantly associated with the decreased PAG-Pcu (r = 0.49, p = .016) and increased VTA-hippocampus rsFC (r = -0.77, p < .001). Compared with VGAIT control, VGAIT produced decreased PAG-paracentral lobule/posterior cingulate cortex/Pcu, middle cingulate cortex (MCC), and medial prefrontal cortex rsFC, and decreased VTA-caudate and MCC rsFC. Direct comparison between real acupuncture and VGAIT showed that VGAIT decreased rsFC in PAG-paracentral lobule/MCC, VTA-caudate/anterior cingulate cortex/nucleus accumbens, and VTA-MCC.

CONCLUSIONS

Results suggest that both actual and imagined acupuncture can modulate key regions in the descending pain modulatory system and reward networks, but through different pathways. Identification of different pain relief mechanisms may facilitate the development of new pain management methods.

Acupuncture Versus Sham Acupuncture: A Meta-Analysis on Evidence for Longer-term Effects of Acupuncture in Musculoskeletal Disorders

EDITORIAL NOTE

The original Letter to the Editor prepared by Jones et al was based on the initial electronic version then contained several important procedural errors that resulted in erroneous conclusions as noted by Jones et al in their original Letter. Subsequently, the authors of the Letter to the Editor were notified of the corrections and they then prepared the revised Letter to the Editor published here. Jones et al did note a remaining error in Table 5 of their corrected manuscript. Based on Jones et al's observation, Lenoir et al were notified of an error on Table 5 and have addressed this in the current version of their paper published in this issue. We appreciate the input of the authors of the letter and the positive response of the author(s) of this article. Dennis C. Turk, PhD Editor-in-Chief OBJECTIVE:: Acupuncture is a common modality in the therapy of musculoskeletal disorders. The evidence for acupuncture has been examined frequently, but a clear synthesis of previous research is currently lacking. This meta-analysis aimed to summarize the evidence for nonimmediate effects of acupuncture on pain, functionality, and quality of life in patients with musculoskeletal disorders, when compared with sham acupuncture.

METHODS

Search results from PubMed and Web of Science were brought together. All screening procedures were executed twice by 2 independent researchers. The pooled standardized mean difference (SMD) with its confidence interval (CI) was estimated at follow-up at <1 month, 1 to 3 months, 3 to 6 months, and >6 months.

RESULTS

For pain, the SMD equalled respectively -0.47 (CI -0.76 to -0.19), -0.27 (CI -0.44 to -0.11), -0.32 (CI -0.51 to -0.13) and -0.12 (CI -0.36 to 0.11) for <1 month, 1 to 3 months, 3 to 6 months, and >6 months follow-up. For functionality, the pooled SMD equalled -0.43 (CI -0.76 to -0.10), -0.41 (CI -0.76 to -0.05), 0.07 (CI -0.22 to 0.36), and -0.13 (-0.46 to 0.19). In the area of QOL, pooled SMD of respectively 0.20 (CI 0.04 to 0.35), 0.19 (CI -0.01 to 0.39), 0.02 (CI -0.09 to 0.14) and -0.04 (CI -0.25 to 0.16) were obtained.

DISCUSSION

A significant difference in therapy effect, favoring acupuncture, was found for pain at <1 month, 1 to 3 months, and 3 to 6 months, as well as on quality of life at <1 month, and on functionality at <1 month and 1 to 3 months.

Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis

INTRODUCTION

Placebos are used as a control treatment that is meant to be indistinguishable from the active intervention. However, where substantive placebo effects may occur, studies that do not include a nonplacebo control arm may underestimate the overall effect of the intervention (active plus placebo components). This study aimed to determine the relative magnitude of the placebo effect associated with nutritional supplements (caffeine and extracellular buffers) by meta-analyzing data from studies containing both placebo and nonplacebo control sessions.

METHODS

Bayesian multilevel meta-analysis models were used to estimate pooled effects and express the placebo effect as a percentage of the overall intervention effect.

RESULTS

Thirty-four studies were included, with the median pooled effect size (ES0.5) indicating a very small (ES0.5 = 0.09 (95% credible interval (CrI), 0.01-0.17)) improvement in the performance of placebo compared with control. There was no moderating effect of exercise type (capacity or performance), exercise duration, or training status. The comparison between active intervention and control indicated a small to medium effect (ES0.5 = 0.37 (95% CrI, 0.20-0.56)). Expressed in relative terms, the placebo effect was equivalent to 25% (75% CrI, 16%-35%) and 59% (75% CrI, 34%-94%) of the total intervention effect for buffers and caffeine.

CONCLUSIONS

These results demonstrate a very small but potentially important placebo effect with nutritional supplementation studies. A substantive proportion of supplement effects may be due to placebo effects, with the relative proportion influenced by the magnitude of the overall ergogenic effect. Where feasible, intervention studies should use nonplacebo control-arm comparators to identify the proportion of the effect estimated to come from placebo effects and avoid underestimating the overall benefits that the physiological plus psychobiological aspects associated with an intervention provide in the real world.

Different routes of administration in chronic migraine prevention lead to different placebo responses: a meta-analysis

ABSTRACT

Placebo response is a powerful determinant of health outcomes in several disorders. Meta-analysis of clinical trials in pain conditions shows that it can contribute up to 75% of the overall treatment effect. Placebo response deriving from different routes of administration is poorly understood in primary headaches' pharmacological prevention. Thus, this meta-analysis aims to analyze how different routes of administration affect the placebo response in chronic migraine (CM). We conducted a meta-analysis with 7 randomized, double-blind, placebo-controlled clinical trials, with 5672 patients older than 18 years who suffer from CM without associated comorbidities. We compared those who received a placebo-administered agent for the preventive treatment of CM subcutaneous, endovenous, or oral against those who received multiple head injections. The primary outcome was reduction in the number of days with migraine in the month assessed at 12, 16, and 24 weeks of treatment compared with baseline. Our study shows that placebo responses were greater when botulinum toxin was applied to the head, followed by intravenous injection of the anti-calcitonin gene-related peptide monoclonal antibody eptinezumab. Oral topiramate and subcutaneous monoclonal showed no difference, being inferior to head injection. Administration route affects placebo responses in CM preventive treatment. Elucidating the underlying mechanisms that mediate a placebo response in migraine treatment is beneficial to clinical practice and drug development, especially when comparing drugs with different routes of administration, with the effect of application to the head being superior to the other routes in this study. In our study the placebo response accounted for approximately 75% of the therapeutic gain in the treatment of CM.

Optimized acupuncture treatment (acupuncture and intradermal needling) for cervical spondylosis-related neck pain: a multicenter randomized controlled trial

ABSTRACT

Cervical spondylosis (CS)-related neck pain is difficult to treat because of its degenerative nature. The aim of this 9-center, single-blinded, randomized controlled trial was to evaluate the efficacy of optimized acupuncture for CS-related neck pain. Participants who met the inclusion criteria were randomized to optimized, shallow, and sham acupuncture groups (1:1:1). The primary outcome was the change from baseline in the Northwick Park Neck Pain Questionnaire score at week 4. Participants were followed up until week 16. Of the 896 randomized participants, 857 received ≥1 intervention session; 280, 286, and 291 received optimized, shallow, and sham acupuncture, respectively. A total of 835 (93.2%) participants completed the study. At week 4, significant differences (P < 0.001) were observed in the changes in Northwick Park Neck Pain Questionnaire scores between the optimized acupuncture group and both the shallow {7.72 (95% confidence interval [CI], 5.57-9.86)} and sham acupuncture (10.38 [95% CI, 8.25-12.52]) groups. The difference in the scores at week 16 between the optimized acupuncture group and the shallow (8.84 [95% CI, 6.34-11.34]) and sham acupuncture (10.81 [95% CI, 8.32-13.30]) groups were significant. The center effect indicated wide variability in the treatment effects (Cohen's d = 0.01-2.19). Most SF-36 scores were higher in the optimized acupuncture group than those in the other groups. These results suggest that 4-week optimized acupuncture treatment alleviates CS-related neck pain and improves the quality of life, with the effects persisting for minimum 3 months. Therefore, acupuncture can have positive effects on CS-related neck pain, although the effect size may vary widely.

Effects of Patients' Expectation in Dermatology: Evidence from Experimental and Clinical Placebo Studies and Implications for Dermatologic Practice and Research

Patients' expectations towards the benefit of a treatment are key determinants of placebo responses and can affect the development and course of medical conditions and the efficacy and tolerability of active medical treatment. The mechanisms mediating these placebo and nocebo effects have been best described in the field of experimental pain and placebo analgesia. However, also in dermatology experimental and clinical studies demonstrate that various skin diseases such as inflammatory dermatoses and allergic reactions can be modulated by patients' expectations. Dermatologists should consider the important modulatory role of patients' expectations on the efficacy and tolerability of specific treatments and the key role of verbal information, patients' prior treatment experiences (associative learning), and the quality and quantity of doctor-patient communication in shaping treatment expectation. As a consequence, techniques aiming at maximizing patients' expectation effects should be implemented into daily clinical routine. By contrast, in clinical studies expectation effects should be maximally controlled and harmonized to improve the "assay sensitivity" to detect new compounds. Further translational studies, also in dermatoses that have not been investigated yet, are needed to better characterize the mechanisms underlying patients' expectation and to gain further insights into potential clinical implications of these effects in dermatologic conditions. Therefore, in this review, we provide a brief overview on the concept of expectation effects on treatment outcome in general, summarize what is already known about this topic for dermatologic diseases, and finally present the relevance of this topic in clinical dermatology.

A pain science education and walking program to increase physical activity in people with symptomatic knee osteoarthritis: a feasibility study

Supplemental Digital Content is Available in the Text.

This feasibility study of contemporary pain science education to increase activity levels in people with painful knee osteoarthritis supports progression to a larger trial.

Introduction:

Nine of 10 people with knee osteoarthritis are inactive. Unhelpful pain beliefs may negatively influence physical activity levels. Targeting these unhelpful pain beliefs, through contemporary pain science education (PSE), may provide benefit.

Objectives:

To evaluate the feasibility of conducting a clinical trial to determine the effect of adding PSE (vs adding sham ultrasound) to an individualised, physiotherapist-led education and walking program in people with painful knee osteoarthritis.

Methods:

Twenty participants were randomised (1:1) into the PSE group or Control group, each receiving 4 in-person weekly treatments, then 4 weeks of at-home activities (weekly telephone check-in). Clinical outcomes and physical activity (7 days of wrist-worn accelerometry) were assessed at baseline, 4 (clinical outcomes only), 8, and 26 weeks. A priori feasibility criteria for recruitment, intervention adherence, viability of wrist-based accelerometry, and follow-up retention were set. Perceived intervention credibility, acceptability, and usefulness from participants and clinicians were assessed (ratings, written/verbal feedback).

Results:

Most feasibility criteria were met. On average, 7 adults/wk were eligible, with 70% recruited. Treatment compliance was high (in-person: 80% PSE; 100% Control; at-home: 78% PSE; 75% Control). Wrist-based accelerometry had >75% valid wear-time. Sufficient follow-up rates were not achieved (26 weeks: 65%). Participant and clinician feedback highlighted that PSE was too complex and did not match patient expectations of “physiotherapy”, that sham ultrasound was problematic (clinician), but that both treatments had high credibility, acceptability, and usefulness.

Conclusions:

Progression to a full trial is warranted. Strategies to increase participant retention, refine the PSE content/delivery, and replace/remove the sham intervention are required.

Electroacupuncture decreases inflammatory pain through a pro-resolving mechanism involving the peripheral annexin A1-formyl peptide receptor 2/ALX-opioid receptor pathway

The pro-resolving mechanism is a recently described endogenous process that controls inflammation. The present study evaluated components of this mechanism, including annexin 1 (ANXA1) and the formyl peptide receptor 2/ALX (FPR2/ALX) receptor, in the antihyperalgesic effect induced by electroacupuncture (EA) in an animal model of persistent peripheral inflammation. Male Swiss mice underwent intraplantar (i.pl.) injection with complete Freund's adjuvant (CFA). Mechanical hyperalgesia was assessed with von Frey monofilaments. Animals were treated with EA (2-10 Hz, ST36-SP6) or subcutaneous BML-111 injection (FPR2/ALX agonist) for 5 consecutive days. In a separate set of experiments, on the first and fifth days after CFA injection, animals received i.pl. WRW4 (FPR2/ALX antagonist) or naloxone (non-selective opioid receptor antagonist) before EA or BML-111 injection. Paw protein levels of FPR2/ALX and ANXA1 were evaluated on the second day after CFA injection by western blotting technique. EA and BML-111 reduced mechanical hyperalgesia. I.pl. naloxone or WRW4 prevented the antihyperalgesic effect induced by either EA or BML-111. EA increased ANXA1 but did not alter FPR2/ALX receptor levels in the paw. Furthermore, i.pl. pretreatment with WRW4 prevented the increase of ANXA1 levels induced by EA. This work demonstrates that the EA antihyperalgesic effect on inflammatory pain involves the ANXA1/FPR2/ALX pro-resolution pathway. This effect appears to be triggered by the activation of FPR2/ALX receptors and crosstalk communication with the opioid system.

Applying the Power of the Mind in Acupuncture Treatment of Pain

Background: Healing is a complicated process that can have several components including the self-healing properties of the body, the nonspecific effects of treatment (e.g., the power of the mind), and the specific effects of an intervention. This article first discusses the brain imaging studies on placebo acupuncture analgesia and the modulation effects of expectancy on real acupuncture in healthy subjects. Then, it introduces some attempts to translate findings from healthy subjects to patient population using power of the mind as a way to enhance acupuncture's treatment effects on chronic pain. After that, a new alternative method which merges acupuncture and imagery, while also drawing on power of the mind, is presented. Finally, the specific effects of acupuncture are discussed. Conclusions: Elucidating the mechanism underlying power of the mind would provide new opportunities for boosting the therapeutic effect of acupuncture treatment and furthering the development of new alternative interventions.

[Use of placebo in French hospitals: data from polyvalent medicine units]

A placebo drug is defined as a treatment without any specific pharmacological efficacy, that works when the patient thinks to receive an active treatment, through a psychological and physiological mechanism. This study aimed to evaluate the use of placebo in French hospitals, in Polyvalent Medicine units. A questionnaire comprising 15 items was sent to 372 units. The analysis of 153 responses was conducted from dynamic crosstabs in Excel and using the R software available online. The survey confirmed that the use of placebos in hospital is frequent, with nearly 2/3 of professionals answering the questionnaire declared to use it. The oral capsule is the most commonly used form. Placebo is mainly administered at night, in case of pain, insomnia or anxiety, to so-called "difficult" patients. Placebo is not always given after medical prescription. In most cases, patients are not informed that they receive a placebo. The majority of professionals believed in the placebo effect but considered to be insufficiently informed and trained in the use of placebo in current practice. Although the placebo effect is now demonstrated, ethical and legal considerations recommend placebo treatment only on medical prescription, with the prior information of the patient. The placebo could be used as complementary therapy to conventional treatment in the cases of this therapeutic effectiveness has been demonstrated. Professionals should be trained in the use of placebo in order to avoid nocebo effect and potentiate beneficial effects of placebo.

Electroacupuncture pretreatment attenuates brain injury in a mouse model of cardiac arrest and cardiopulmonary resuscitation via the AKT/eNOS pathway

AIMS

This study aims to examine the effects of electroacupuncture (EA) pretreatment on brain injury after cardiac arrest and cardiopulmonary resuscitation (CA/CPR) and its underlying mechanisms.

MATERIALS AND METHODS

Adult male C57BL/6 mice were subjected to 6 min of cardiac arrest induced with a potassium chloride infusion and resuscitated by chest compressions and an epinephrine infusion. During the 3 days prior to CA/CRP, mice received EA pretreatment (1 mA, 2 Hz; daily session of 30 min) at the Baihui acupoint (GV20) once daily. Stimulation at a nonacupoint served as a control. In mechanistic studies, mice received the AKT inhibitor LY294002 or endothelial nitric oxide synthase (eNOS) inhibitor L-NIO 30 min before EA pretreatment. A neurological assessment was conducted 24 h after CA/CRP, followed by animal sacrifice and evaluation of physiological brain damage.

KEY FINDINGS

CA/CPR resulted in severe brain injury as evidenced by neurological deficits and increased neuronal apoptosis, oxidative stress and the proinflammatory cytokines TNF-α and IL-6. EA pretreatment at the GV20 acupoint but not at a nonacupoint attenuated the neurological deficits and the pathological changes induced by CA/CPR. LY294002 or L-NIO eliminated the neuroprotective effects of the EA pretreatment.

SIGNIFICANCE

This study showed that EA pretreatment at the GV20 acupoint can protect the brain from damage associated with globalized ischemia followed by reperfusion and that these protective effects occur via the AKT/eNOS signaling pathway.

Analgesic Effects Evoked by Real and Imagined Acupuncture: A Neuroimaging Study

Acupuncture can provide therapeutic analgesic benefits but is limited by its cost and scheduling difficulties. Guided imagery is a commonly used method for treating many disorders, such as chronic pain. The present study examined a novel intervention for pain relief that integrates acupuncture with imagery called video-guided acupuncture imagery treatment (VGAIT). A total of 27 healthy subjects were recruited for a crossover-design study that included 5 sessions administered in a randomized order (i.e., baseline and 4 different interventions). We investigated changes in pain threshold and fMRI signals modulated by: 1) VGAIT, watching a video of acupuncture previously administered on the participant's own body at baseline while imagining it being concurrently applied; 2) a VGAIT control condition, watching a video of a cotton swab touching the skin; 3) real acupuncture; and 4) sham acupuncture. Results demonstrated that real acupuncture and VGAIT significantly increased pain threshold compared with respective control groups. Imaging showed that real acupuncture produced greater activation of the insula compared with VGAIT. VGAIT produced greater deactivation at the rostral anterior cingulate cortex. Our findings demonstrate that VGAIT holds potential clinical value for pain management.

The placebo and its effects: A psychoneuroendocrinological perspective

Placebos are usually employed deceptively in clinical trials in order to control for non-specific effects. However, since placebos themselves have been found to cause clinically relevant changes and in some cases are indistinguishable from the verum they are tested against, this theoretically inert, but practically effective intervention has become a scientific discipline in its own right. In this review, it is argued that placebos are generic and genuine biopsychosocial interventions and as such are highly interesting candidates for a psychoneuroendocrinological perspective. Yet, despite a considerable conceptual proximity between explanatory models of placebos and their effects with psychoneuroendocrine models and findings, placebos have thus far not been subject to systematic psychoneuroendocrine examination. Consequently, it would be highly interesting and informative to make placebos the target of psychoneuroendocrine scrutiny.

Multivariate resting-state functional connectivity predicts responses to real and sham acupuncture treatment in chronic low back pain

Despite the high prevalence and socioeconomic impact of chronic low back pain (cLBP), treatments for cLBP are often unsatisfactory, and effectiveness varies widely across patients. Recent neuroimaging studies have demonstrated abnormal resting-state functional connectivity (rsFC) of the default mode, salience, central executive, and sensorimotor networks in chronic pain patients, but their role as predictors of treatment responsiveness has not yet been explored. In this study, we used machine learning approaches to test if pre-treatment rsFC can predict responses to both real and sham acupuncture treatments in cLBP patients. Fifty cLBP patients participated in 4 weeks of either real (N = 24, age = 39.0 ± 12.6, 16 females) or sham acupuncture (N = 26, age = 40.0 ± 13.7, 15 females) treatment in a single-blinded trial, and a resting-state fMRI scan prior to treatment was used in data analysis. Both real and sham acupuncture can produce significant pain reduction, with those receiving real treatment experiencing greater pain relief than those receiving sham treatment. We found that pre-treatment rsFC could predict symptom changes with up to 34% and 29% variances for real and sham treatment, respectively, and the rsFC characteristics that were significantly predictive for real and sham treatment differed. These results suggest a potential way to predict treatment responses and may facilitate the development of treatment plans that optimize time, cost, and available resources.

Brain and psychological determinants of placebo pill response in chronic pain patients

The placebo response is universally observed in clinical trials of pain treatments, yet the individual characteristics rendering a patient a ‘placebo responder’ remain unclear. Here, in chronic back pain patients, we demonstrate using MRI and fMRI that the response to placebo ‘analgesic’ pills depends on brain structure and function. Subcortical limbic volume asymmetry, sensorimotor cortical thickness, and functional coupling of prefrontal regions, anterior cingulate, and periaqueductal gray were predictive of response. These neural traits were present before exposure to the pill and most remained stable across treatment and washout periods. Further, psychological traits, including interoceptive awareness and openness, were also predictive of the magnitude of response. These results shed light on psychological, neuroanatomical, and neurophysiological principles determining placebo response in RCTs in chronic pain patients, and they suggest that the long-term beneficial effects of placebo, as observed in clinical settings, are partially predictable.

People vary in the extent to which they feel better after taking an inert, placebo, treatment, but the basis for individual placebo response is unclear. Here, the authors show how brain structural and functional variables, as well as personality traits, predict placebo response in those with chronic back pain.

Unique aspects of clinical trials of invasive therapies for chronic pain

Nearly all who review the literature conclude that the role of invasive procedures to treat chronic pain is poorly characterized because of the lack of “definitive” studies. The overt nature of invasive treatments, along with the risks, technical skills, and costs involved create challenges to study them. However, these challenges do not completely preclude evaluating invasive procedure effectiveness and safety using well-designed methods. This article reviews the challenges of studying outcomes of invasive therapies to treat pain and discuss possible solutions. Although the following discussion can apply to most invasive therapies to treat chronic pain, it is beyond the scope of the article to individually cover every invasive therapy used. Therefore, most of the examples focus on injection therapies to treat spine pain, spinal cord stimulation, and intrathecal drug therapies.

The National Cancer Institute's Conference on Acupuncture for Symptom Management in Oncology: State of the Science, Evidence, and Research Gaps

The Division of Cancer Treatment and Diagnosis, Office of Cancer Complementary and Alternative Medicine, at the National Cancer Institute (NCI) held a symposium on "Acupuncture for Cancer Symptom Management" on June 16 and 17, 2016. Invited speakers included 19 scientists and scholars with expertise in acupuncture and cancer research from the United States, Europe, and China. The conference reviewed the NCI's grant funding on acupuncture, analyzed the needs of cancer patients, reviewed safety issues, and assessed both the current scientific evidence and research gaps of acupuncture in oncology care. Researchers and stakeholders presented and discussed basic mechanisms of acupuncture; clinical evidence for specific symptoms; and methodological challenges such as placebo effects, novel biostatistical methods, patient-reported outcomes, and comparative effectiveness research. This paper, resulting from the conference, summarizes both the current state of the science and clinical evidence of oncology acupuncture, identifies key scientific gaps, and makes recommendations for future research to increase understanding of both the mechanisms and effects of acupuncture for cancer symptom management.

Experimental and placebo auriculotherapy for stressed nurses: randomized controlled trial

OBJECTIVE

To compare the efficacy of experimental auriculotherapy and placebo auriculotherapy with sham points for the treatment of stress in nurses of a charity hospital in São Paulo.

METHOD

Randomized, single-blind, controlled trial. The sample consisted of 168 nurses with medium and high stress levels according to the List of Stress Symptoms (LSS). The participants were randomized to three groups: Auriculotherapy (G1), Placebo (G2) and Control (G3). Groups 1 and 2 received 12 sessions, twice a week. The points used in Group 1 were: Shenmen and Brainstem; in Group 2 the points were: External Ear and Face Area. The three groups were evaluated at baseline, after eight sessions, 12 sessions and in a follow-up (after 15 days).

RESULTS

Group 1 achieved a 43% reduction and a 1.81 Cohen d index (high effect), presenting statistical difference after eight sessions, maintained in the follow-up evaluation (p <0.001), according to Analysis of Variance. Group 2 achieved a 26% reduction, with Cohen's d index of 0.86 (great effect), achieving a difference after 12 sessions (p<0.001), maintained in the follow-up (p <0.05). The G3 did not present stress reduction.

CONCLUSION

Experimental auriculotherapy achieved greater stress reduction among nurses, but there was no statistical difference between the two intervention groups. Brazilian Registry of Clinical Trials: RBR-req2792.

Increasing effort without noticing: A randomized controlled pilot study about the ergogenic placebo effect in endurance athletes and the role of supplement salience

Purpose

Previous research shows that endurance performance can be enhanced by placebo ergogenic aids. This study investigates the ergogenic placebo response, which we define as an increase in objective and physiological effort without an increase in subjective effort, in competitive cyclists. The primary objective of this study is to explore the role of supplement salience in the ergogenic placebo response, while the secondary aim is to assess whether believing to have taken an inactive placebo supplement attenuates the desired ergogenic effect.

Methods

We employed a double-blind placebo-controlled study design and compared a high salience (pudding) to a low salience (capsules) ergogenic placebo supplement and to a no treatment control group. Thirty-four male athletes (30.0 ± 5.7 years) performed two self-regulated time trials on an isokinetic cycling ergometer, one without intervention serving as a baseline and one with intervention according to group assignment. At both time trials, power output (objective effort), blood lactate (physiological effort) and the rating of perceived exertion (subjective effort) were measured.

Results

Receiving a high salience supplement can increase physiological and objective effort without a proportional rise in subjective effort, suggesting a decoupling of perceived exertion and endurance performance. Low salience and control group both showed no such ergogenic placebo response. Athletes’ belief concerning the true nature of the ergogenic aid (inactive placebo vs. ergogenic supplement) did not influence the ergogenic placebo response.

Conclusion

High salience placebo ergogenic aids can elicit enhanced performance without the athlete noticing (exertion), and deception of athletes seems unnecessary as even believing to have received an inactive placebo supplement maintains the ergogenic placebo response.

Placebo Effects Across Self-Report, Clinician Rating, and Objective Performance Tasks Among Women With Post-Traumatic Stress Disorder: Investigation of Placebo Response in a Pharmacological Treatment Study of Post-Traumatic Stress Disorder

PURPOSE/BACKGROUND

For a drug to acquire Food and Drug Administration approval, it must significantly outperform placebo treatment. In recent years, the placebo effect seems to be increasing in neuropsychiatric conditions. Here, we examine placebo effects across self-reported, clinically rated, and performance-based data from a trial using a corticotropin-releasing hormone receptor type 1 (CRHR1) antagonist for treatment of post-traumatic stress disorder (PTSD).

METHODS/PROCEDURES

Women with chronic PTSD were randomized to treatment with either GSK561679, a CRHR1 antagonist, or placebo. Before randomization, participants completed self-report scales, clinician-rated measures of PTSD and depression symptoms, and objective tests of cognition and functioning. Differences in change scores on measures were compared between GSK561679 and placebo-treated participants.

FINDINGS/RESULTS

GSK561679 failed to produce any significant improvement in the participants. A substantial placebo effect was observed in both self-report and clinical rating scales, with effect sizes up to 1.5 SD. No single variable predicted placebo-related changes. Notably, there was an improvement on objective performance measures of cognition that exceeded previous standards for practice effects.

IMPLICATIONS/CONCLUSIONS

Participants in this trial manifested retest effects on performance-based measures of cognition. Notably, they had minimal prior experience with performance-based assessments. Experiencing the structure and support of a clinical trial may have contributed to significant reductions in subject-reported and clinician-rated PTSD symptom levels. The improvement seen across all assessment domains was consistent with that seen in previous studies where the active treatments separated from placebo. Investigators conducting clinical trials treating PTSD patients should expect placebo effects and design studies accordingly.

Enhancing treatment of osteoarthritis knee pain by boosting expectancy: A functional neuroimaging study

Objectives

Expectation can significantly modulate pain and treatment effects. This study aims to investigate if boosting patients' expectancy can enhance the treatment of knee osteoarthritis (KOA), and its underlying brain mechanism.

Methods

Seventy-four KOA patients were recruited and randomized to three groups: boosted acupuncture (with a manipulation to enhance expectation), standard acupuncture, or treatment as usual (TAU). Each patient underwent six treatments before being debriefed, and four additional treatments after being debriefed. The fMRI scans were applied during the first and sixth treatment sessions.

Results

We found significantly decreased knee pain in the boosted acupuncture group compared to the standard acupuncture or TAU groups after both six and ten treatments. Resting state functional connectivity (rsFC) analyses using the nucleus accumbens (NAc) as the seed showed rsFC increases between the NAc and the medial prefrontal cortex (MPFC)/rostral anterior cingulate cortex (rACC) and dorsolateral prefrontal cortex in the boosted group as compared to the standard acupuncture group after multiple treatments. Expectancy scores after the first treatment were significantly associated with increased NAc-rACC/MPFC rsFC and decreased knee pain following treatment.

Conclusions

Our study provides a novel method and mechanism for boosting the treatment of pain in patients with KOA. Our findings may shed light on enhancing outcomes of pharmacological and integrative medicines in clinical settings.

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Acupuncture with enhanced expectancy produced greater pain relief in KOA patients.

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NAc – ACC/MPFC rsFC increased after acupuncture with enhanced expectancy.

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NAc – ACC/MPFC rsFC increases are associated with clinical improvements.

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Our findings provide a novel method for boosting the treatment of chronic pain.

A Functional Neuroimaging Study of Expectancy Effects on Pain Response in Patients With Knee Osteoarthritis

Placebo treatments and healing rituals share much in common, such as the effects of expectancy, and have been used since the beginning of human history to treat pain. Previous mechanistic neuroimaging studies investigating the effects of expectancy on placebo analgesia have used young, healthy volunteers. Using functional magnetic resonance imaging (fMRI), we aimed to investigate the neural mechanisms by which expectancy evokes analgesia in older adults living with a chronic pain disorder and determine whether there are interactions with active treatment. In this fMRI study, we investigated the brain networks underlying expectancy in participants with chronic pain due to knee osteoarthritis (OA) after verum (genuine) and sham electroacupuncture treatment before and after experiencing calibrated experimental heat pain using a well tested expectancy manipulation model. We found that expectancy significantly and similarly modulates the pain experience in knee OA patients in both verum (n = 21, 11 female; mean ± SD age 57 ± 7 years) and sham (n = 22, 15 female; mean ± SD age 59 ± 7 years) acupuncture treatment groups. However, there were different patterns of changes in fMRI indices of brain activity associated with verum and sham treatment modalities specifically in the lateral prefrontal cortex. We also found that continuous electroacupuncture in knee OA patients can evoke significant regional coherence decreases in pain associated brain regions. Our results suggest that expectancy modulates the experience of pain in knee OA patients but may work through different pathways depending on the treatment modality and, we speculate, on pathophysiological states of the participants.

PERSPECTIVE

To investigate the neural mechanisms underlying pain modulation, we used an expectancy manipulation model and fMRI to study response to heat pain stimuli before and after verum or sham acupuncture treatment in chronic pain patients. Both relieve pain and each is each associated with a distinct pattern of brain activation.

Acupuncture for Chronic Pain: Update of an Individual Patient Data Meta-Analysis

Despite wide use in clinical practice, acupuncture remains a controversial treatment for chronic pain. Our objective was to update an individual patient data meta-analysis to determine the effect size of acupuncture for 4 chronic pain conditions. We searched MEDLINE and the Cochrane Central Registry of Controlled Trials randomized trials published up until December 31, 2015. We included randomized trials of acupuncture needling versus either sham acupuncture or no acupuncture control for nonspecific musculoskeletal pain, osteoarthritis, chronic headache, or shoulder pain. Trials were only included if allocation concealment was unambiguously determined to be adequate. Raw data were obtained from study authors and entered into an individual patient data meta-analysis. The main outcome measures were pain and function. An additional 13 trials were identified, with data received for a total of 20,827 patients from 39 trials. Acupuncture was superior to sham as well as no acupuncture control for each pain condition (all P < .001) with differences between groups close to .5 SDs compared with no acupuncture control and close to .2 SDs compared with sham. We also found clear evidence that the effects of acupuncture persist over time with only a small decrease, approximately 15%, in treatment effect at 1 year. In secondary analyses, we found no obvious association between trial outcome and characteristics of acupuncture treatment, but effect sizes of acupuncture were associated with the type of control group, with smaller effects sizes for sham controlled trials that used a penetrating needle for sham, and for trials that had high intensity of intervention in the control arm. We conclude that acupuncture is effective for the treatment of chronic pain, with treatment effects persisting over time. Although factors in addition to the specific effects of needling at correct acupuncture point locations are important contributors to the treatment effect, decreases in pain after acupuncture cannot be explained solely in terms of placebo effects. Variations in the effect size of acupuncture in different trials are driven predominantly by differences in treatments received by the control group rather than by differences in the characteristics of acupuncture treatment.

PERSPECTIVE

Acupuncture is effective for the treatment of chronic musculoskeletal, headache, and osteoarthritis pain. Treatment effects of acupuncture persist over time and cannot be explained solely in terms of placebo effects. Referral for a course of acupuncture treatment is a reasonable option for a patient with chronic pain.

Nerve Stimulation: Immunomodulation and Control of Inflammation

Neuronal stimulation is an emerging field in modern medicine to control organ function and re-establish physiological homeostasis during illness. Transdermal nerve stimulation with electroacupuncture is currently endorsed by the World Health Organization (WHO) and the National Institutes of Health (NIH), and is used by millions of people to control pain and inflammation. Recent advances in electroacupuncture may permit activation of specific neuronal networks to prevent organ damage in inflammatory and infectious disorders. Experimental studies of nerve stimulation are also providing new information on the functional organization of the nervous system to control inflammation and its clinical implications in infectious and inflammatory disorders. These studies may allow the design of novel non-invasive techniques for nerve stimulation to help to control immune and organ functions.

[Placebo effect in clinical trials with allergen-specific immunotherapy with inhalant allergens]

Placebo effects play an important role in the treatment of allergic diseases. Therefore, in this study, we analysed the described effects of placebo in all double-blind placebo-controlled clinical trials of allergen-specific immunotherapy (ASIT) with inhalant allergens (birch, grass, house dust mites) listed in the tables (updated July 2016) attached to the German S2k guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases. The most common placebo consisted of verum without allergen, but when the subcutaneous route was used, histamine was sometimes added. From the 33 studies analysed no conclusions could be drawn regarding the pure placebo effect. The symptom medication score (SMS) from an adequate baseline period was described in one single study. An untreated population was not included in any study. Indirect evidence points to substantial placebo effects in up to 77% of the subjects with respect to retrospective, subjective parameters. Well-known factors influencing the placebo effect such as age, gender, application route/composition of the placebo, individual and cultural differences, severity of symptoms at the beginning and the probability of receiving verum have not been addressed regarding ASIT and could not be estimated from available data. Taken together regarding ASIT the placebo effect has been investigated inadequately. In spite of significant expenditure of time and costs future ASIT studies should include assessment of the SMS in an adequate baseline period and preferably include an untreated trial arm. A better understanding of placebo effects in ASIT trials will improve the design of clinical trials and the assessment of therapeutic effects.

A Network Meta-Analysis of Clinical Management Strategies for Treatment-Resistant Hypertension: Making Optimal Use of the Evidence

BACKGROUND

With the addition of surgical interventions to current medicinal treatments, it is increasingly challenging for clinicians to rationally choose among the various options for treating patients with apparent treatment-resistant hypertension (ATRHTN). This study aims to establish the comparative effectiveness of mineralocorticoid receptor antagonists (MRA), renal denervation (RDN), darusentan and central arteriovenous anastomosis (CAA) for patients with ATRHTN by performing a network meta-analysis.

METHODS

Data Sources: Studies from recent meta-analyses for RDN and placebo effect were supplemented with a systematic search for MRAs in ATRHTN in the Pubmed, EMBASE, CINAHL and Cochrane databases through November 2016.

STUDY SELECTION

Randomized controlled trials comparing treatment options for patients with ATRHTN.

DATA EXTRACTION AND SYNTHESIS

Data were extracted using predefined data extraction forms, including the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. A Bayesian random effects model was used to conduct a network meta-analysis. Spironolactone was used as the main comparator. Main Outcomes and Measures: Reduction in 24-h ambulatory blood pressure measurement (ABPM).

RESULTS

Twenty articles met our inclusion criteria, and seven treatment alternatives were compared. Compared to MRA, CAA had the highest probability of being more effective, further reducing 24-h SBP (-4.8 mmHg [-13.0, 3.7]) and 24-h DBP (-9.7 mmHg [-18, -0.63]). This difference is likely to be clinically meaningful, with a probability of 78 and 96% at a threshold of a 2-mmHg reduction in blood pressure.

CONCLUSIONS

When compared to MRA as anchor, darusentan, CAA and RDN are not more effective in achieving a clinically significant reduction in ambulatory blood pressure in individuals with apparent treatment-resistant hypertension.

Brain structural properties predict psychologically mediated hypoalgesia in an 8-week sham acupuncture treatment for migraine

Neuroimaging studies described brain structural changes that comprise the mechanisms underlying individual differences in migraine development and maintenance. However, whether such interindividual variability in migraine was observed in a pretreatment scan is a predisposition for subsequent hypoalgesia to placebo treatment that remains largely unclear. Using T1-weighted imaging, we investigated this issue in 50 healthy controls (HC) and 196 patients with migraine without aura (MO). An 8-week double-blinded, randomized, placebo-controlled acupuncture was used, and we only focused on the data from the sham acupuncture group. Eighty patients participated in an 8-weeks sham acupuncture treatment, and were subdivided (50% change in migraine days from baseline) into recovering (MOr) and persisting (MOp) patients. Optimized voxel-based morphometry (VBM) and functional connectivity analysis were performed to evaluate brain structural and functional changes. At baseline, MOp and MOr had similar migraine activity, anxiety and depression; reduced migraine days were accompanied by decreased anxiety in MOr. In our findings, the MOr group showed a smaller volume in the left medial prefrontal cortex (mPFC), and decreased mPFC-related functional connectivity was found in the default mode network. Additionally, the reduction in migraine days after placebo treatment was significantly associated with the baseline gray matter volume of the mPFC which could also predict post-treatment groups with high accuracy. It indicated that individual differences for the brain structure in the pain modulatory system at baseline served as a substrate on how an individual facilitated or diminished hypoalgesia responses to placebo treatment in migraineurs. Hum Brain Mapp 38:4386-4397, 2017. © 2017 Wiley Periodicals, Inc.

Brain Mechanisms of the Placebo Effect: An Affective Appraisal Account

Placebos are sham medical treatments. Nonetheless, they can have substantial effects on clinical outcomes. Placebos depend on a person's psychological and brain responses to the treatment context, which influence appraisals of future well-being. Appraisals are flexible cognitive evaluations of the personal meaning of events and situations that can directly impact symptoms and physiology. They also shape associative learning processes by guiding what is learned from experience. Appraisals are supported by a core network of brain regions associated with the default mode network involved in self-generated emotion, self-evaluation, thinking about the future, social cognition, and valuation of rewards and punishment. Placebo treatments for acute pain and a range of clinical conditions engage this same network of regions, suggesting that placebos affect behavior and physiology by changing how a person evaluates their future well-being and the personal significance of their symptoms.

Placebo Mechanisms of Manual Therapy: A Sheep in Wolf's Clothing?

When a physical therapist provides a manual therapy (MT) intervention for a patient presenting with pain and the patient experiences a positive clinical outcome, we cannot answer as to why this occurs. Would we continue to devote valuable time and financial resources to learning and improving our skills in providing MT interventions if the related clinical outcomes were placebo responses? In this Viewpoint, the authors conceptualize placebo as an active and important mechanism of MT and argue that placebo mechanisms deserve consideration as an important component of the treatment effect. J Orthop Sports Phys Ther 2017;47(5):301-304. doi:10.2519/jospt.2017.0604.