How placebos change the patient's brain

Effectiveness of non-pharmacological interventions for pain reduction following chest tube removal: A systematic review and network meta-analysis

OBJECTIVE

This study aimed to determine the most effective non-pharmacological intervention for pain relief following chest tube removal in adult patients.

METHODS

We performed a systematic review with network meta-analysis, searching electronic databases for randomized controlled trials up to January 20, 2024. Compared to control or placebo groups, the trials included adult patients receiving non-pharmacological interventions, such as cold therapy, relaxation exercises, music therapy, transcutaneous electrical nerve stimulation, or aromatherapy. Data analysis utilized a random-effects model, reporting standardized mean differences (SMD) with 95% confidence intervals (CI), and treatment ranking was determined through surface under the cumulative ranking analysis and forest plots.

RESULTS

Sixteen studies enrolling 1,342 patients were included, with moderate to high heterogeneity. Cold therapy and relaxation exercises effectively reduced pain after chest tube removal, with SMD of -1.84 (95 % CI: -2.81 to -0.87) and -2.04 (95 % CI: -3.43 to -0.65), respectively, from baseline to immediately post-removal. From baseline to ten to twenty minutes after removal, both therapies continued to show significant pain reduction, with SMD of -1.96 (95 % CI: -3.14 to -0.77) for cold therapy and -2.01 (95 % CI: -3.75 to -0.28) for relaxation exercises. Sensitivity analysis supported these findings, and cold therapy's efficacy appeared unaffected by obesity. However, publication bias, possibly due to small study samples, was noted.

CONCLUSIONS

Cold therapy and relaxation exercises proved most effective for reducing pain immediately and up to ten to twenty minutes after chest tube removal. Given their cost-effectiveness, lack of side effects, and ease of use, we recommend relaxation exercises as a practical alternative to cold therapy. Nonetheless, further studies are needed to comprehensively assess non-pharmacological options for managing chest tube removal pain.

IMPLICATIONS FOR CLINICAL PRACTICE

Incorporate cold therapy and relaxation exercises into post-chest tube removal pain management to improve patient comfort and minimize reliance on pharmacological interventions.

Justice for Placebo: Placebo Effect in Clinical Trials and Everyday Practice

The placebo effect has been widely documented across various medical conditions, demonstrating its ability to influence both subjective and objective outcomes. Placebo responses can significantly improve symptoms in these different conditions, such as pain, Parkinson's disease, depression, anxiety, and addiction. Psychological mechanisms, particularly the power of patient expectations, appear to play a central role, with neurobiological evidence supporting the activation of dopamine, endogenous opioids, and endocannabinoids in response to placebo interventions. Studies have demonstrated that placebo injections and more complex procedures, including sham surgeries, can produce therapeutic effects comparable to real treatments, particularly in pain management and neurological disorders. Moreover, placebo responses could be amplified when patients are aware of receiving treatment, as shown by research on open-label placebos and open versus hidden medical treatments. The effectiveness of 0.9% sodium chloride solution as a placebo in clinical trials is debated, with some studies indicating its potential to induce clinical improvements, though it may not be an ideal control in inflammatory pain conditions. Advances in neuroimaging have revealed that placebo treatments trigger tangible biological processes in the brain and body and are supported by psychological and physiological mechanisms that interact, suggesting real biological processes are involved in the observed effects. Overall, the growing understanding of placebo mechanisms suggests that incorporating placebo-based strategies, with patient awareness and appropriate ethical considerations, may offer significant potential for improving patient outcomes, particularly in chronic pain, mental health, and neurological conditions.

Reclaiming ritual in palliative care: A hermeneutic narrative review

OBJECTIVES

To explore the potential of incorporating personally meaningful rituals as a spiritual resource for Western secular palliative care settings. Spiritual care is recognized as critical to palliative care; however, comprehensive interventions are lacking. In postmodern societies, the decline of organized religion has left many people identifying as "no religion" or "spiritual but not religious." To assess if ritual could provide appropriate and ethical spiritual care for this growing demographic requires comprehensive understanding of the spiritual state and needs of the secular individual in postmodern society, as well as a theoretical understanding of the elements and mechanisms of ritual. The aim of this paper is to provide a comprehensive and theoretically informed exploration of these elements through a critical engagement with heterogeneous literatures.

METHODS

A hermeneutic narrative review, inspired by complexity theory, underpinned by a view of understanding of spiritual needs as a complex mind-body phenomenon embedded in sociohistorical context.

RESULTS

This narrative review highlights a fundamental spiritual need in postmodern post-Christian secularism as need for embodied spiritual experience. The historical attrition of ritual in Western culture parallels loss of embodied spiritual experience. Ritual as a mind-body practice can provide an embodied spiritual resource. The origin of ritual is identified as evolutionary adaptive ritualized behaviors universally observed in animals and humans which develop emotional regulation and conceptual cognition. Innate human behaviors of creativity, play, and communication develop ritual. Mechanisms of ritual allow for connection to others as well as to the sacred and transcendent.

SIGNIFICANCE OF RESULTS

Natural and innate behaviors of humans can be used to create rituals for personally meaningful spiritual resources. Understanding the physical properties and mechanisms of ritual making allows anyone to build their own spiritual resources without need of relying on experts or institutionalized programs. This can provide a self-empowering, client-centered intervention for spiritual care.

Does a Prolonged Sham Theta Burst Stimulation Intervention Regimen Outperform Standard Care in Terms of Functional Recovery and Pain Relief After an Upper Limb Fracture?

OBJECTIVE

In a recent sham-controlled 13-session prolonged continuous theta burst stimulation intervention protocol, recovery from upper limb fracture at both 1 and 3 months was better than anticipated in patients assigned to the sham intervention group. To determine whether potential placebo effect and close patient monitoring affected recovery, the current study aimed to compare clinical outcomes between sham-treated participants who also received standard care with similarly injured patients who only received standard care.

METHODS

Twenty participants with isolated upper limb fractures from the sham group were seen 13 times post-fracture (1 baseline session, 10 treatments, and 2 follow-ups [1 and 3 months]) over 3 months. They completed the self-reported Disabilities of Arm, Shoulder, and Hand (DASH) questionnaire and the Numerical Rating Scale for pain assessment at 1 and 3 months post-fracture. Two control groups were recruited: 43 participants at 1 month post-fracture and another 40 participants at 3 months post-fracture. These control groups completed the same questionnaires online, without any lab visits.

RESULTS

At 1 month, patients from the sham group reported significantly less functional impairments on the DASH (p = .010). At 3 months, significantly more patients from the control group reported functional limitations (72.5% versus sham's 40%, p = .015).

CONCLUSIONS

Although preliminary, these findings suggest clinically significant beneficial effects of the sham intervention over the standard care groups. This positive sham intervention effect may be attributed to a placebo response that includes the placebo effect associated with sham rTMS, but also the impact of various factors such as the close monitoring of the injury.

Muscular Performance and Blood Pressure After Different Pre-Strength Training Strategies in Recreationally Strength-Trained Women: Cross-Over Trial

BACKGROUND

This study aimed to investigate the acute effects of different pre-ST strategies on muscular performance and blood pressure (BP) responses in recreationally strength-trained women.

METHODS

Twelve overweight women with normal BP were recruited and performed six experimental protocols in a randomized order: (1) control protocol (CC), where BP was assessed without exercises performed; (2) ST; (3) foam rolling warm-up followed by ST (FR + ST); (4) specific warm-up followed by ST (SW + ST); (5) aerobic exercise followed by ST (AE + ST); and (6) stretching exercises followed by ST (SE + ST). ST consisted of three sets at 80% of 10 repetition maximum with a self-suggested rest interval between sets for bench press, back squat, bench press 45°, front squat, lat pull-down, leg press, shoulder press, and leg extension.

RESULTS

All experimental protocol had a lower total training volume, fatigue index, and repetitions performance in relation to ST (p < 0.05). No significant reduction was observed in systolic and diastolic BP for any protocol or exercise, although the effect size magnitudes ranged from trivial to large. Decreases in maximum repetitions, resistance to fatigue, and total training volume were performed before ST as warm-up strategies. However, these strategies indicated a clinical reduction in BP with a large and meaningful magnitude (effect size) in recreationally strength-trained women with normal to elevated BP.

CONCLUSIONS

The results of this investigation may help to influence decision-making by practitioners who desire to elicit a post-exercise hypotension response in both subjects with normal BP and hypertension.

Placebo effects in randomized trials of pharmacological and neurostimulation interventions for mental disorders: An umbrella review

There is a growing literature exploring the placebo response within specific mental disorders, but no overarching quantitative synthesis of this research has analyzed evidence across mental disorders. We carried out an umbrella review of meta-analyses of randomized controlled trials (RCTs) of biological treatments (pharmacotherapy or neurostimulation) for mental disorders. We explored whether placebo effect size differs across distinct disorders, and the correlates of increased placebo effects. Based on a pre-registered protocol, we searched Medline, PsycInfo, EMBASE, and Web of Knowledge up to 23.10.2022 for systematic reviews and/or meta-analyses reporting placebo effect sizes in psychopharmacological or neurostimulation RCTs. Twenty meta-analyses, summarising 1,691 RCTs involving 261,730 patients, were included. Placebo effect size varied, and was large in alcohol use disorder (g = 0.90, 95% CI [0.70, 1.09]), depression (g = 1.10, 95% CI [1.06, 1.15]), restless legs syndrome (g = 1.41, 95% CI [1.25, 1.56]), and generalized anxiety disorder (d = 1.85, 95% CI [1.61, 2.09]). Placebo effect size was small-to-medium in obsessive-compulsive disorder (d = 0.32, 95% CI [0.22, 0.41]), primary insomnia (g = 0.35, 95% CI [0.28, 0.42]), and schizophrenia spectrum disorders (standardized mean change = 0.33, 95% CI [0.22, 0.44]). Correlates of larger placebo response in multiple mental disorders included later publication year (opposite finding for ADHD), younger age, more trial sites, larger sample size, increased baseline severity, and larger active treatment effect size. Most (18 of 20) meta-analyses were judged 'low' quality as per AMSTAR-2. Placebo effect sizes varied substantially across mental disorders. Future research should explore the sources of this variation. We identified important gaps in the literature, with no eligible systematic reviews/meta-analyses of placebo response in stress-related disorders, eating disorders, behavioural addictions, or bipolar mania.

Comparison of the symptom networks of long-COVID and chronic fatigue syndrome: From modularity to connectionism

The objective was to compare the symptom networks of long-COVID and chronic fatigue syndrome (CFS) in conjunction with other theoretically relevant diagnoses in order to provide insight into the etiology of medically unexplained symptoms (MUS). This was a cross-sectional comparison of questionnaire items between six groups identified by clinical diagnosis. All participants completed a 65-item psychological and somatic symptom questionnaire (GSQ065). Diagnostically labelled groups were long-COVID (N = 107), CFS (N = 254), irritable bowel syndrome (IBS, N = 369), fibromyalgia (N = 1,127), severe asthma (N = 100) and healthy group (N = 207). The 22 symptoms that best discriminated between the six groups were selected for network analysis. Connectivity, fragmentation and number of symptom clusters (statistically related symptoms) were assessed. Compared to long-COVID, the symptom networks of CFS, IBS and fibromyalgia had significantly lower connectivity, greater fragmentation and more symptom clusters. The number of clusters varied between 9 for CFS and 3 for severe asthma, and the content of clusters varied across all groups. Of the 33 symptom clusters identified over the six groups 30 clusters were unique. Although the symptom networks of long-COVID and CFS differ, the variation of cluster content across the six groups is inconsistent with a modular causal structure but consistent with a connectionist (network, parallel distributed processing) biological basis of MUS. A connectionist structure would explain why symptoms overlap and merge between different functional somatic syndromes, the failure to discover a biological diagnostic test and how psychological and behavioral interventions are therapeutic.

"I am open to self-belief": A study examining the impact of open-label effects on postexercise affect and postintervention exercise behaviour

The contribution of placebo effects can be measured by manipulating psychological factors, such as positive expectations for exercise outcomes, without the need for traditional placebos (such as inert substances). While placebo effects are well known, research has revealed intriguing findings suggesting that placebos can have beneficial effects even when studies are performed without deception. Open-label placebo (OLP) interventions (prescribed honestly), which harness the power of belief, may represent another effective method for enhancing the benefits of exercise effects. This study compared the efficacy of a conventional placebo intervention, an OLP intervention, and a control group among 89 individuals. Participants' levels of affective response after exercise and exercise behaviour were assessed during the intervention period (4 weeks) and at follow-up (4 weeks). The results revealed similar levels of improvement in all outcomes across the three conditions. Both the conventional placebo and OLP intervention groups exhibited greater enhancements in postexercise enjoyment. OLP interventions demonstrated distinct advantages in terms of remembered affect and expectation fulfilment. Nonetheless, neither intervention directly stimulated postintervention exercise behaviour. Future studies should continue to explore the impact of OLP interventions on adherence to exercise behaviour.

Brain and body: Implanting a placebo in the brain to alleviate pain

Placebo analgesia is well documented in human populations but remains relatively under-researched in rodent models. Now researchers have engineered robust circuit-based placebo analgesia in mice and identified pathways mediating the effect of expectations, offering new insights into harnessing placebo for pain management.

Effect of a comfort scale compared with a pain numerical rate scale on opioids consumption in postanaesthesia care unit: the COMFORT study

BACKGROUND

The way that pain is assessed in the PACU could impact on postoperative pain and analgesic consumption. However, there is currently no evidence to support this speculation. The authors hypothesised that using a comfort scale reduces postoperative opioid consumption when compared with a standard numerical rating scale (NRS) to evaluate pain in the PACU.

METHODS

In this cluster-randomised trial, patients were assessed using either a comfort scale (comfort group) or a pain NRS (NRS group). The primary outcome was the opioid consumption in the PACU. The main secondary outcomes were postoperative pain, nausea and vomiting, length of stay in the PACU, and satisfaction.

RESULTS

Of 885 randomised patients, 860 were included in the analysis. Opioid consumption in the PACU was comparable in the comfort and NRS groups (median [interquartile range [IQR] 0 (0-5) vs 0 (0-6); P=0.2436), irrespective of the type of surgical procedure. The majority of patients did not need any postoperative opioid (59% in the comfort group and 56% in the NRS group, P=0.2260). There was no difference in postoperative pain, nausea and vomiting, time to reach an Aldrete score ≥9 after extubation, and global satisfaction.

CONCLUSIONS

Using a comfort scale to assess pain in the PACU did not spare any opioid compared with use of a standard NRS. Further studies focusing on patients at risk of increased postoperative opioid consumption are necessary.

CLINICAL TRIAL REGISTRATION

NCT05234216.

Reverse-engineering placebo analgesia

Placebo analgesia is a widely observed clinical phenomenon. Establishing a robust mouse model of placebo analgesia is needed for careful dissection of the underpinning circuit mechanisms. However, previous studies failed to observe consistent placebo effects in rodent models of chronic pain. We wondered whether strong placebo analgesia can be reverse engineered using general-anesthesia-activated neurons in the central amygdala (CeAGA) that can potently suppress pain. Indeed, in both acute and chronic pain models, pairing a context with CeAGA-mediated pain relief produced robust context-dependent analgesia, exceeding that produced by morphine in the same paradigm. CeAGA neurons receive monosynaptic inputs from temporal lobe areas that could potentially relay contextual cues directly to CeAGA neurons. However, in vivo imaging showed that CeAGA neurons were not reactivated in the conditioned context, despite mice displaying a strong analgesic phenotype. This finding suggests that the placebo-context-induced pain relief engages circuits beyond CeAGA neurons and relies on plasticity in other analgesic and/or nociceptive circuits. Our results show that conditioning with the activation of a central pain-suppressing circuit is sufficient to engineer placebo analgesia and that purposefully linking a context with an active treatment could be a means to harness the power of placebo for pain relief.

Is non-invasive neuromodulation a viable technique to improve neuroplasticity in individuals with acquired brain injury? A review

Objective

This study aimed to explore and evaluate the efficacy of non-invasive brain stimulation (NIBS) as a standalone or coupled intervention and understand its mechanisms to produce positive alterations in neuroplasticity and behavioral outcomes after acquired brain injury (ABI).

Data sources

Cochrane Library, Web of Science, PubMed, and Google Scholar databases were searched from January 2013 to January 2024.

Study selection

Using the PICO framework, transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) randomized controlled trials (RCTs), retrospective, pilot, open-label, and observational large group and single-participant case studies were included. Two authors reviewed articles according to pre-established inclusion criteria.

Data extraction

Data related to participant and intervention characteristics, mechanisms of change, methods, and outcomes were extracted by two authors. The two authors performed quality assessments using SORT.

Results

Twenty-two studies involving 657 participants diagnosed with ABIs were included. Two studies reported that NIBS was ineffective in producing positive alterations or behavioral outcomes. Twenty studies reported at least one, or a combination of, positively altered neuroplasticity and improved neuropsychological, neuropsychiatric, motor, or somatic symptoms. Twenty-eight current articles between 2020 and 2024 have been studied to elucidate potential mechanisms of change related to NIBS and other mediating or confounding variables.

Discussion

tDCS and TMS may be efficacious as standalone interventions or coupled with neurorehabilitation therapies to positively alter maladaptive brain physiology and improve behavioral symptomology resulting from ABI. Based on postintervention and follow-up results, evidence suggests NIBS may offer a direct or mediatory contribution to improving behavioral outcomes post-ABI.

Conclusion

More research is needed to better understand the extent of rTMS and tDCS application in affecting changes in symptoms after ABI.

Boosting treatment outcomes via the patient-practitioner relationship, treatment-beliefs or therapeutic setting. A systematic review with meta-analysis of contextual effects in chronic musculoskeletal pain

OBJECTIVE: To ascertain whether manipulating contextual effects (e.g. interaction with patients, or beliefs about treatments) boosted the outcomes of non-pharmacological and non-surgicaltreatments for chronic primary musculoskeletal pain. DESIGN: Systematic review of randomized controlled trials. DATA SOURCES: We searched for trials in six databases, citation tracking, and clinical trials registers. We included trials that compared treatments with enhanced contextual effects with the same treatments without enhancement in adults with chronic primary musculoskeletal pain. DATA SYNTHESIS: The outcomes of interest were pain intensity, physical functioning, global ratings of improvement, quality of life, depression, anxiety, and sleep. We evaluated risk of bias and certainty of the evidence using Cochrane Risk of Bias tool 2.0 and the GRADE approach, respectively. RESULTS: Of 17637 records, we included 10 trials with 990 participants and identified 5 ongoing trials. The treatments were acupuncture, education, exercise training, and physical therapy. The contextual effects that were improved in the enhanced treatments were patient-practitioner relationship, patient beliefs and characteristics, therapeutic setting/environment, and treatment characteristics. Our analysis showed that improving contextual effects in non-pharmacological and non-surgical treatments may not make much difference on pain intensity (mean difference [MD] : -1.77, 95%-CI: [-8.71; 5.16], k = 7 trials, N = 719 participants, Scale: 0-100, GRADE: Low)) or physical functioning (MD: -0.27, 95%-CI: [-1.02; 0.49], 95%-PI: [-2.04; 1.51], k = 6 , N = 567, Scale: 0-10, GRADE: Low) in the short-term and at later follow-ups. Sensitivity analyses revealed similar findings. CONCLUSION: Whilst evidence gaps exist, per current evidence it may not be possible to achieve meaningful benefit for patients with chronic musculoskeletal pain by manipulating the context of non-pharmacological and non-surgical treatments. TRIAL REGISTRATION: This systematic review was prospectively registered in PROSPERO (registration number: CRD42023391601).

Trajectory and magnitude of response in adults with anxiety disorders: a Bayesian hierarchical modeling meta-analysis of selective serotonin reuptake inhibitors, serotonin norepinephrine reuptake inhibitors, and benzodiazepines

BACKGROUND

How the trajectory of response to medication (and placebo response) varies among selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), benzodiazepines and across anxiety disorders is unknown.

METHODS

We performed a meta-analysis using weekly symptom severity data from randomized, parallel-group, placebo-controlled trials of SSRIs, SNRIs, and benzodiazepines in adults with anxiety disorders. Response was modeled for the standardized change in anxiety using Bayesian hierarchical models.

RESULTS

Across 122 trials (N=15,760), SSRIs, SNRIs, and benzodiazepines produced significant improvement in anxiety compared to placebo. Benzodiazepines produced faster improvement by the first week of treatment (p < 0.001). By week 8, the response for benzodiazepines and SSRIs (p = 0.103) and SNRIs (p = 0.911) did not differ nor did SSRIs and SNRIs differ (p = 0.057), although for patients with generalized anxiety disorder (GAD), the benzodiazepines produced greater improvement than SNRIs at week 8 (difference - 12.42, CrI: -25.05 to -0.78, p = 0.037). Medication response was similar across anxiety disorders except for benzodiazepines, which produced greater improvement over the first 4 weeks compared to SSRIs and SNRIs in panic disorder. For SSRIs and SNRIs, women improved more than men, and for benzodiazepines, older patients improved more compared to younger patients. Finally, placebo response plateaued by week 4 of treatment, and, at week 8, social anxiety disorder trials had lower placebo response compared to other anxiety disorders.

CONCLUSIONS

Benzodiazepines show early improvement compared to SSRIs and SNRIs. However, by week 8, all treatments yield similar results. Patient characteristics influence the improvement trajectory and magnitude, suggesting potential for personalized medication selection.

Placebo Effects Are Small on Average in the 7.5% CO2 Inhalational Model of Generalized Anxiety

BACKGROUND

Anxiety disorders are highly prevalent and socio-economically costly. Novel pharmacological treatments for these disorders are needed because many patients do not respond to current agents or experience unwanted side effects. However, a barrier to treatment development is the variable and large placebo response rate seen in trials of novel anxiolytics. Despite this, the mechanisms that drive placebo responses in anxiety disorders have been little investigated, possibly due to low availability of convenient experimental paradigms. We aimed to develop and test a novel protocol for inducing placebo anxiolysis in the 7.5% CO2 inhalational model of generalized anxiety in healthy volunteers.

METHODS

Following a baseline 20-minute CO2 challenge, 32 healthy volunteers were administered a placebo intranasal spray labelled as either the anxiolytic "lorazepam" or "saline." Following this, participants surreptitiously underwent a 20-minute inhalation of normal air. Post-conditioning, a second dose of the placebo was administered, after which participants completed another CO2 challenge.

RESULTS

Participants administered sham "lorazepam" reported significant positive expectations of reduced anxiety (P = .001), but there was no group-level placebo effect on anxiety following CO2 challenge post-conditioning (Ps > .350). Surprisingly, we found many participants exhibited unexpected worsening of anxiety, despite positive expectations.

CONCLUSIONS

Contrary to our hypothesis, our novel paradigm did not induce a placebo response, on average. It is possible that effects of 7.5% CO2 inhalation on prefrontal cortex function or behavior in line with a Bayesian predictive coding framework attenuated the effect of expectations on subsequent placebo response. Future studies are needed to explore these possibilities.

Heart is deceitful above all things: Threat expectancy induces the illusory perception of increased heartrate

It has been suggested that our perception of the internal milieu, or the body's internal state, is shaped by our beliefs and previous knowledge about the body's expected state, rather than being solely based on actual interoceptive experiences. This study investigated whether heartbeat perception could be illusorily distorted towards prior subjective beliefs, such that threat expectations suffice to induce a misperception of heartbeat frequency. Participants were instructed to focus on their cardiac activity and report their heartbeat, either tapping along to it (Experiment 1) or silently counting (Experiment 2) while ECG was recorded. While completing this task, different cues provided valid predictive information about the intensity of an upcoming cutaneous stimulation (high- vs. low- pain). Results showed that participants expected a heart rate increase over the anticipation of high- vs. low-pain stimuli and that this belief was perceptually instantiated, as suggested by their interoceptive reports. Importantly, the perceived increase was not mirrored by the real heart rate. Perceptual modulations were absent when participants executed the same task but with an exteroceptive stimulus (Experiment 3). The findings reveal, for the first time, an interoceptive illusion of increased heartbeats elicited by threat expectancy and shed new light on interoceptive processes through the lenses of Bayesian predictive processes, providing tantalizing insights into how such illusory phenomena may intersect with the recognition and regulation of people's internal states.

Reverse engineering placebo analgesia

Placebo analgesia is a widely observed clinical phenomenon. Establishing a robust mouse model of placebo analgesia is needed for careful dissection of the underpinning circuit mechanisms. However, previous studies failed to observe consistent placebo effects in rodent models of chronic pain. We wondered whether strong placebo analgesia can be reverse engineered using general anesthesia-activated neurons in the central amygdala (CeA GA ) that can potently suppress pain. Indeed, in both acute and chronic pain models, pairing a context with CeA GA -mediated pain relief produced robust context-dependent analgesia, exceeding that induced by morphine in the same paradigm. We reasoned that if the analgesic effect was dependent on reactivation of CeA GA neurons by conditioned contextual cues, the analgesia would still be an active treatment, rather than a placebo effect. CeA GA neurons indeed receive monosynaptic inputs from temporal lobe areas that could potentially relay contextual cues directly to CeA GA . However, in vivo imaging showed that CeA GA neurons were not re-activated in the conditioned context, despite mice displaying a strong analgesic phenotype, supporting the notion that the cue-induced pain relief is true placebo analgesia. Our results show that conditioning with activation of a central pain-suppressing circuit is sufficient to engineer placebo analgesia, and that purposefully linking a context with an active treatment could be a means to harness the power of placebo for pain relief.

Effectiveness of Cold Therapy for Pain and Anxiety Associated with Chest Tube Removal: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

To assess the effectiveness of cold therapy for pain and anxiety associated with chest tube removal.

DESIGN

A Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES

Articles were searched from Cochrane Library, PubMed, Embase, CINAHL, ProQuest, Airiti Library, China National Knowledge Infrastructure, and the National Digital Library of Theses and Dissertations in Taiwan.

REVIEW/ANALYSIS METHODS

Eight electronic databases were searched from inception to August 20, 2022. The Cochrane Risk of Bias 2.0 tool was used to assess the quality of the included studies. Using a random-effects model, we calculated Hedges' g and its associated confidence interval to evaluate the effects of cold therapy. Cochrane's Q test and an I2 test were used to detect heterogeneity, and moderator and meta-regression analyses were conducted to explore possible sources of heterogeneity. Publication bias was assessed using a funnel plot, Egger's test, and trim-and-fill analysis.

RESULTS

We examined 24 trials involving 1,821 patients. Cold therapy significantly reduced pain during and after chest tube removal as well as anxiety after chest tube removal (Hedges' g: -1.28, -1.27, and -1.80, respectively). Additionally, the effect size of cold therapy for reducing anxiety after chest tube removal was significantly and positively associated with that of cold therapy for reducing pain after chest tube removal.

CONCLUSIONS

Cold therapy can reduce pain and anxiety associated with chest tube removal.

Non-linear processing and reinforcement learning to predict rTMS treatment response in depression

BACKGROUND

Forecasting the efficacy of repetitive transcranial magnetic stimulation (rTMS) therapy can lead to substantial time and cost savings by preventing futile treatments. To achieve this objective, we've formulated a machine learning approach aimed at categorizing patients with major depressive disorder (MDD) into two groups: individuals who respond (R) positively to rTMS treatment and those who do not respond (NR).

METHODS

Preceding the commencement of treatment, we obtained resting-state EEG data from 106 patients diagnosed with MDD, employing 32 electrodes for data collection. These patients then underwent a 7-week course of rTMS therapy, and 54 of them exhibited positive responses to the treatment. Employing Independent Component Analysis (ICA) on the EEG data, we successfully pinpointed relevant brain sources that could potentially serve as markers of neural activity within the dorsolateral prefrontal cortex (DLPFC). These identified sources were further scrutinized to estimate the sources of activity within the sensor domain. Then, we integrated supplementary physiological data and implemented specific criteria to yield more realistic estimations when compared to conventional EEG analysis. In the end, we selected components corresponding to the DLPFC region within the sensor domain. Features were derived from the time-series data of these relevant independent components. To identify the most significant features, we used Reinforcement Learning (RL). In categorizing patients into two groups - R and NR to rTMS treatment - we utilized three distinct classification algorithms including K-Nearest Neighbor (KNN), Support Vector Machine (SVM), and Multilayer Perceptron (MLP). We assessed the performance of these classifiers through a ten-fold cross-validation method. Additionally, we conducted a statistical test to evaluate the discriminative capacity of these features between responders and non-responders, opening the door for further exploration in this field.

RESULTS

We identified EEG features that can anticipate the response to rTMS treatment. The most robust discriminators included EEG beta power, the sum of bispectrum diagonal elements in the delta and beta frequency bands. When these features were combined into a single vector, the classification of responders and non-responders achieved impressive performance, with an accuracy of 95.28 %, specificity at 94.23 %, sensitivity reaching 96.29 %, and precision standing at 94.54 %, all achieved using SVM.

CONCLUSIONS

The results of this study suggest that the proposed approach, utilizing power, non-linear, and bispectral features extracted from relevant independent component time-series, has the capability to forecast the treatment outcome of rTMS for MDD patients based solely on a single pre-treatment EEG recording session. The achieved findings demonstrate the superior performance of our method compared to previous techniques.

Placebo effects in mental health disorders: protocol for an umbrella review

INTRODUCTION

Given the high prevalence of mental health disorders and their significant socioeconomic burden, there is a need to develop improved treatments, and to evaluate them through placebo-controlled trials. However, the magnitude of the placebo response in randomised controlled trials to test medications may be substantial, affecting their interpretation. Therefore, improved understanding of the patient, trial and mental disorder factors that influence placebo responses would inform clinical trial design to better detect active treatment effects. There is a growing literature exploring the placebo response within specific mental health disorders, but no overarching synthesis of this research has been produced to date. We present a protocol for an umbrella review of systematic reviews and/or meta-analyses in which we aim to understand the effect size and potential predictors of placebo response within, and across, mental health disorders.

METHODS AND ANALYSIS

We will systematically search databases (Medline, PsycINFO, EMBASE+EMBASE Classic, Web of Knowledge) for systematic reviews and/or meta-analyses that report placebo effect size in clinical trials in patients with mental health disorders (initial search date 23 October 2022). Screening of abstracts and full texts will be done in pairs. We will extract data to qualitatively examine how placebo effect size varies across mental health disorders. We also plan to qualitatively summarise predictors of increased placebo response identified either quantitatively (eg, through meta-regression) or qualitatively. Risk of bias will be assessed using the AMSTAR-2 tool. We aim to not only summarise the current literature but also to identify gaps in knowledge and generate further hypotheses.

ETHICS AND DISSEMINATION

We do not believe there are any specific ethical considerations relevant to this study. We will publish the results in a peer-reviewed journal.

The effect of erenumab on brain network function in episodic migraine patients: a randomized, placebo-controlled clinical trial (RESET BRAIN)

BACKGROUND

We aimed to explore whether erenumab, a monoclonal antibody targeting the calcitonin gene-related peptide receptor, could exert a central effect on brain network function in migraine, and investigate the persistence of such an effect following treatment discontinuation.

METHODS

This was a randomized, double-blind, placebo-controlled, multicenter trial with a crossover design performed in adult episodic migraine patients with previous treatment failure. Patients were randomized (1:1) to 12 weeks of erenumab 140 mg or placebo, followed by a 12-week crossover. Resting state (RS) functional connectivity (FC) changes of brain networks involved in migraine were investigated using a seed-based correlation approach.

RESULTS

Sixty-one patients were randomized to treatment. In each treatment sequence, 27 patients completed the visit at week 12. Forty-four enrolled patients, 22 in each treatment sequence, completed the study procedures with no major protocol violations. We observed a carry-over effect of erenumab during the placebo treatment and therefore data analysis was performed as a parallel comparison of erenumab vs placebo of the first 12 weeks of treatment. From baseline to week 12, compared to placebo, patients receiving erenumab showed RS FC changes within the cerebellar, thalamic and periaqueductal gray matter networks, significantly associated with clinical improvement. Compared to non-responders, patients achieving a 50% reduction in migraine days had distinct patterns of thalamic and visual network RS FC. Brain RS FC changes reversed when erenumab was stopped. A lower baseline RS FC of the pontine network identified patients responding to erenumab.

CONCLUSION

Erenumab modulates RS FC of networks involved in migraine pathophysiology. In line with clinical response, erenumab-induced brain RS FC changes tend to reverse when treatment is stopped.

Role of expectations in clinical outcomes after deep brain stimulation in patients with Parkinson's disease: a systematic review

Deep brain stimulation (DBS) is a well-established treatment that significantly improves the motor symptoms of patients with Parkinson's disease (PD); however, patients may experience post-operative psychological distress and social maladjustments. This phenomenon has been shown to be related to patients' pre-operative cognitive representations, such as expectations. In this systematic review, we discuss the findings on the role of the expectations of patients with PD regarding the clinical outcomes of DBS to identify areas of intervention to improve pre-operative patient education and promote successful post-operative psychosocial adjustment. PubMed was searched for relevant articles published up to 16 January 2023. Of the 84 identified records, 10 articles focusing on the treatment expectations of patients with PD undergoing DBS were included in this review. The selected studies were conducted among cohorts of patients with different DBS targets, among which the most common was the bilateral subthalamic nucleus. Overall, the data showed that patients' expectations contribute to treatment efficacy. Experiments investigating the placebo effect itself have shown clinical improvement after the induction of positive therapeutic expectations; conversely, unrealistic treatment expectations can affect patient satisfaction after surgery, clinical outcomes, and subjective well-being. This review highlights the need for routine clinical practice to better investigate and manage patients' pre-operative expectations, as well as multidisciplinary education to improve patient satisfaction and psychosocial adjustment after DBS.

How Do Expectations Modulate Pain? A Motivational Perspective

Expectations can profoundly modulate pain experience, during which the periaqueductal gray (PAG) plays a pivotal role. In this article, we focus on motivationally evoked neural activations in cortical and brainstem regions both before and during stimulus administration, as has been demonstrated by experimental studies on pain-modulatory effects of expectations, in the hope of unraveling how the PAG is involved in descending and ascending nociceptive processes. This motivational perspective on expectancy effects on the perception of noxious stimuli sheds new light on psychological and neuronal substrates of pain and its modulation, thus having important research and clinical implications.

When Patients' Assessments of Treatment for Subjective Symptoms are At Odds with Authoritative Assessments in the Biomedical Literature: The Case of Patients Treated with Acupuncture for Low Back Pain in a Traditional Chinese Medicine Clinic in China (and Story of a Bewildered Chicken)

Assessments of treatments for 'subjective symptoms' are problematic and potentially contentious. These are symptoms without ascertainable pathophysiology, also referred to as 'medically unexplained.' Treatments of them may be assessed from different perspectives, and an assessment as seen from one perspective may be discrepant with an assessment as seen from another perspective. The observational study described in the paper represents one perspective. Patients in the study were treated with acupuncture for the subjective symptom of low back pain in a Traditional Chinese Medicine Clinic in China; acupuncture is a form of TCM, which is indigenous to China. Shortly after treatment began and six months afterward, patients reported 'clinically important improvements' on a variety of standard, cross-culturally validated outcome measures, including pain intensity, physical functioning, and emotional functioning; this assessment is consistent with numerous assessments of acupuncture in China and other Southeastern Asian countries. On the other hand, clinical trials represent another perspective from which to assess acupuncture. Although assessments based on trials are not uniform, several assessments based on them, including those published in journals such as Lancet and New England Journal of Medicine, conclude that acupuncture is not effective. These trials, however, were mainly situated in the U.S., western European countries, and other WEIRD (Western, Educated, Industrialized, Rich, Democratic) countries. This is notable, because the population of China, the indigenous context of acupuncture, is greater than populations of WEIRD countries combined. Patients' expectations of a treatment such as acupuncture and their prior familiarity with it vary among contexts, and patients' experiences of treatment outcomes may vary accordingly. In short, although clinical trials constitute a test of truth in biomedicine and inform authoritative assessments in WEIRD countries, they do not necessarily represent the truth from the perspective of those experiencing outcomes of especially indigenous treatments for subjective symptoms in non-WEIRD contexts.

Views on and experiences with medicinal cannabis among Canadian veterans who live with pain: A qualitative study

Background

During fiscal year 2021-2022, Veterans Affairs Canada (VAC) reimbursed 18,388 veterans for medicinal cannabis at a cost of $153 million. Yet, it is not known whether the reimbursement program is producing a net benefit for veterans.

Aims

This study investigated the views and experiences Canadian that veterans who live with pain have about medicinal cannabis use, including its use for the management of chronic pain, poor sleep, and emotional distress.

Methods

Twelve Canadian veterans who live with pain-eight men, four women; split across four focus groups-were recruited to participate in a semistructured discussion around their experiences with medicinal cannabis use.

Results

Using inductive thematic analysis, seven broad categories were identified: (1) cannabis use behaviors, (2) reasons for cannabis use, (3) outcomes from cannabis use, (4) facilitators of cannabis use, (5) barriers to cannabis use, (6) stigma around cannabis use, and (7) questions and concerns about cannabis use.

Conclusions

Most veterans initiated cannabis use to manage the symptoms of preexisting medical and/or mental health conditions. Despite some negative side effects, most veterans reported improvements in their overall quality of life, sleep, relationships, mood, and pain. Concern remains around the discrepancy between veterans' qualitative reports of beneficial outcomes from medicinal cannabis use and equivocal findings around the benefit-to-harm ratio in the wider literature. Currently, the VAC reimbursement program remains challenged by unclear indication for which veterans, with what condition(s), at what dose, and in what form medical cannabis is most beneficial.

Does a corticosteroid injection plus exercise or exercise alone add to the effect of patient advice and a heel cup for patients with plantar fasciopathy? A randomised clinical trial

OBJECTIVE

To compare the effectiveness of patient advice plus heel cup alone (PA) versus PA and lower limb exercise (PAX) versus PAX plus corticosteroid injection (PAXI) to improve self-reported pain in patients with plantar fasciopathy.

METHODS

We recruited 180 adults with plantar fasciopathy confirmed by ultrasonography for this prospectively registered three-armed, randomised, single-blinded superiority trial. Patients were randomly allocated to PA (n=62), PA plus self-dosed lower limb heavy-slow resistance training consisting of heel raises (PAX) (n=59), or PAX plus an ultrasound-guided injection of 1 mL triamcinolone 20 mg/mL (PAXI) (n=59). The primary outcome was changed in the pain domain of the Foot Health Status Questionnaire (ranging from 0 'worst' to 100 'best') from baseline to the 12-week follow-up. The minimal important difference in the pain domain is 14.1 points. The outcome was collected at baseline and at 4, 12, 26, and 52 weeks.

RESULTS

The primary analysis found a statistically significant difference between PA and PAXI after 12 weeks favouring PAXI (adjusted mean difference: -9.1 (95% CI -16.8 to -1.3; p=0.023)) and over 52 weeks (adjusted mean difference: -5.2 (95% CI -10.4 to -0.1; p=0.045)). At no follow-up did the mean difference between groups exceed the pre-specified minimal important difference. No statistically significant difference was found between PAX and PAXI or between PA and PAX at any time.

CONCLUSION

No clinically relevant between-group differences were found after 12 weeks. The results indicate that combining a corticosteroid injection with exercise is not superior to exercise or no exercise.

TRIAL REGISTRATION NUMBER

NCT03804008.

A randomized trial that compared brain activity, efficacy and plausibility of open-label placebo treatment and cognitive repappraisal for reducing emotional distress

Placebo pills can reduce emotional distress even when recipients have been informed about the inert nature of the treatment. However, before such open-label placebos (OLPs) can be recommended for general clinical use, their efficacy and acceptability need to be further investigated and compared with established methods for emotion regulation, such as cognitive reappraisal (CR). The current study with functional magnetic resonance imaging compared the effects of an OLP pill with CR for reducing a specific form of emotional distress: disgust. Participants (150 healthy females) were randomly allocated to one of three groups, all of which were exposed to disgusting and neutral images (OLP, CR, PV: passive viewing). It was tested whether the three groups would differ in brain activity and reported disgust. Ratings for the perceived efficacy and plausibility of treatment were also compared between OLP and CR. Both OLP and CR increased the activity in a cognitive control region, the ventrolateral prefrontal cortex. Relative to PV and OLP, CR reduced activity in the putamen and pallidum. These regions play an important role in decoding disgust signals from different modalities. Self-reports indicated that CR was perceived as a more effective and plausible intervention strategy than OLP. In conclusion, CR was a superior method for disgust regulation compared to OLP, both on the subjective as well as the neurobiological level. Future OLP studies are needed to test whether the observed effects generalize to other forms of emotional distress.

The placebo effect of a pink non-caloric, artificially sweetened solution on strength endurance performance and psychological responses in trained individuals

Background: The pink color enhances the perceived sweetness, increasing the individuals' expectation of the presence of sugar/carbohydrate in a beverage. Hence, it is plausible to speculate that providing a pink solution during exercise could induce an ergogenic benefit through a potential placebo effect. Aim: We examined whether ingesting a pink non-caloric, artificially sweetened solution can improve endurance strength exercise performance and psychological responses. Methods: Eighteen strength-trained individuals (34 ± 7 y; 1.74 ± 0.06 m; 79.86 ± 10.91 kg) completed three experimental trials in a randomized, single-blind, crossover counterbalanced fashion. In each trial, participants performed a 5-set strength endurance test at 70% of the one-repetition maximum in the bench press exercise, interspersed by 2 min. Before each set, participants ingested either a pink (PINK) or a transparent (TRANSP) non-caloric, artificially sweetened solution. A session without ingestion (CON) was also completed. Total number of repetitions and psychological responses such as motivation, emotional arousal, affect, and ratings of perceived exertion were obtained throughout the exercise protocol. Results: Total repetitions improved in PINK (60 ± 12 reps) compared to TRANSP (p = 0.03; 56 ± 10 reps; ES = 0.22; ±3.8%) and CON (p = 0.01; 56 ± 9 reps; ES = 0.33; ±6.6%), but no difference occurred between TRANSP and CON (p = 0.84; ES = 0.12; ±2.4%). Comparable responses were observed in motivation, emotional arousal, affect, and ratings of perceived exertion in PINK, TRANSP, and CON trials (all, p > 0.05), despite the greater total physical work performed in PINK trial. Conclusion: Ingesting a pink non-caloric, artificially sweetened solution improved strength endurance performance with comparable psychological responses. These results have implications for future nutritional studies and performance assessments in real-world sports scenarios.

Effects of Prefrontal Transcranial Direct Current Stimulation on Retention of Performance Gains on an Obstacle Negotiation Task in Older Adults

OBJECTIVES

Complex walking in older adults can be improved with task practice and might be further enhanced by pairing transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex. We tested the hypothesis that a single session of practice of a complex obstacle negotiation task paired with active tDCS in older adults would produce greater within-session improvements in walking performance and retention of gains, compared to sham tDCS and no tDCS conditions.

MATERIALS AND METHODS

A total of 50 older adults (mean age = 74.46 years ± 6.49) with self-reported walking difficulty were randomized to receive either active tDCS (active-tDCS group) or sham tDCS (sham-tDCS group) bilaterally to the dorsolateral prefrontal cortex or no tDCS (no-tDCS group). Each group performed ten practice trials of an obstacle negotiation task at their fastest safe speed. Retention of gains in walking performance was assessed with three trials conducted one week later. Within-session effects of practice and between-session retention effects on obstacle negotiation speed were examined.

RESULTS

At the practice session, all three groups exhibited significant within-session gains in walking speed (p ≤ 0.005). However, the gains were significantly greater in the sham-tDCS group than in the active-tDCS and no-tDCS groups (p ≤ 0.03) and were comparable between the active-tDCS and no-tDCS groups (p = 0.89). At one-week follow-up, the active-tDCS group exhibited significant between-session retention of gains and continued "offline" improvement in walking speed (p = 0.005). The active-tDCS group showed significantly greater retention of gains than the no-tDCS (p = 0.02) but not the sham-tDCS group (p = 0.24).

CONCLUSIONS

Pairing prefrontal active tDCS with a single session of obstacle negotiation practice may enhance one-week retention of gains in walking performance compared to no tDCS. However, the evidence is insufficient to suggest a benefit of active tDCS over sham tDCS for enhancing the gains in walking performance. Additional studies with a multisession intervention design and larger sample size are needed to further investigate these findings.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT03122236.

Individual Differences in Pain Catastrophizing and Regional Gray Matter Volume Among Community-dwelling Adults With Chronic Pain: A Voxel-based Morphology Study

OBJECTIVES

Elevations in pain catastrophizing (PC) are associated with more severe pain, emotional distress, and impairment within samples with chronic pain. However, brain structure correlates underlying individual differences in PC are not well understood and predict more severe pain and impairment within samples with chronic pain. This study assessed links between regional gray matter volume (GMV) and individual differences in PC within a large mixed chronic pain sample.

MATERIALS AND METHODS

Chinese adult community dwellers with chronic pain of at least 3 months duration (101 women and 59 men) completed self-report measures of background characteristics, pain severity, depression, and a widely validated PC questionnaire as well as a structural magnetic resonance imagining scan featuring voxel-based morphology to assess regional GMV correlates of PC.

RESULTS

After controlling for demographic correlates of PC, pain severity, and depression, higher PC scores had a significant, unique association with lower GMV levels in the inferior temporal area of the right fusiform gyrus, a region previously implicated in emotion regulation.

DISCUSSION

GMV deficits, particularly in right temporal-occipital emotion regulation regions, correspond to high levels of PC among individuals with chronic pain.

Machine learning approaches and non-linear processing of extracted components in frontal region to predict rTMS treatment response in major depressive disorder

Predicting the therapeutic result of repetitive transcranial magnetic stimulation (rTMS) treatment could save time and costs as ineffective treatment can be avoided. To this end, we presented a machine-learning-based strategy for classifying patients with major depression disorder (MDD) into responders (R) and nonresponders (NR) to rTMS treatment. Resting state EEG data were recorded using 32 electrodes from 88 MDD patients before treatment. Then, patients underwent 7 weeks of rTMS, and 46 of them responded to treatment. By applying Independent Component Analysis (ICA) on EEG, we identified the relevant brain sources as possible indicators of neural activity in the dorsolateral prefrontal cortex (DLPFC). This was served through estimating the generators of activity in the sensor domain. Subsequently, we added physiological information and placed certain terms and conditions to offer a far more realistic estimation than the classic EEG. Ultimately, those components mapped in accordance with the region of the DLPFC in the sensor domain were chosen. Features extracted from the relevant ICs time series included permutation entropy (PE), fractal dimension (FD), Lempel-Ziv Complexity (LZC), power spectral density, correlation dimension (CD), features based on bispectrum, frontal and prefrontal cordance, and a combination of them. The most relevant features were selected by a Genetic Algorithm (GA). For classifying two groups of R and NR, K-Nearest Neighbor (KNN), Support Vector Machine (SVM), and Multilayer Perceptron (MLP) were applied to predict rTMS treatment response. To evaluate the performance of classifiers, a 10-fold cross-validation method was employed. A statistical test was used to assess the capability of features in differentiating R and NR for further research. EEG characteristics that can predict rTMS treatment response were discovered. The strongest discriminative indicators were EEG beta power, the sum of bispectrum diagonal elements in delta and beta bands, and CD. The Combined feature vector classified R and NR with a high performance of 94.31% accuracy, 92.85% specificity, 95.65% sensitivity, and 92.85% precision using SVM. This result indicates that our proposed method with power and nonlinear and bispectral features from relevant ICs time-series can predict the treatment outcome of rTMS for MDD patients only by one session pretreatment EEG recording. The obtained results show that the proposed method outperforms previous methods.

Placebo Effects: The Meaning of Care in Medicine by Pekka Louhiala

Pekka Louhiala crosses disciplines and decades to present a remarkably detailed review of the existing literature on placebos, placebo effects, and related concepts. The problem at hand-and Louhiala does aptly frame it as a problem-is a striking lack of consensus among researchers, scholars, and clinicians regarding virtually all aspects of the placebo topic. In capturing the complexity of this problem, Louhiala expertly compiles an extensive catalog of placebo literature that effectively gives the reader both a map of the territory and a legend to decipher it. He does not, however, give us clear directions to find our way out of the conceptual maze. The focus is often more on the problems than their solutions, which is simultaneously the most notable weakness and the greatest strength of the book.

Touching body, soul, and spirit? Understanding external applications from integrative medicine: A mixed methods systematic review

Introduction

External applications from anthroposophic medicine (EAAM) are touch-based applications such as rhythmical massages, embrocations, and compresses that serve as components of complementary treatment concepts for various diseases. The aim of this review is to gain an understanding of typical indications and outcomes and to systematically assess the effectiveness and safety of EAAM.

Materials and methods

Medline/PubMed, CINAHL, the Cochrane Library, Embase, and PsycINFO were searched through May 2021 and supplemented by searches in specialized databases and personal requests to experts in the field. Studies and case reports on EAAM in patients, as well as healthy individuals, were included in the qualitative synthesis. Outcome parameters depending on each study were grouped as effect themes and assigned to study clusters using Thematic Analysis for a thematic overview of effect patterns.

Results

Four RCTs, 7 cohort studies, 1 mixed-methods, 1 retrospective, 4 qualitative studies, 3 case series, and 25 case reports on EAAM were identified. The analysis indicated various effects of EAAM on physiological as well as psychological health indicators and patterns of effect development. Study quality was found to be high for only 2 studies, and moderate for 1 study, and all remaining 45 studies showed a moderate or high risk of bias or were not ratable with used rating tools.

Conclusion

The included studies present a wide range of potential indications for EAAM, while showing methodological drawbacks. To determine whether EAAM can be considered an effective treatment option, clinical studies exploring the effect of different EAAM modalities on defined patient groups are recommended for the future.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=214030], identifier [CRD42020214030].

Targeting neural correlates of placebo effects

Harnessing the placebo effects would prompt critical ramifications for research and clinical practice. Noninvasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation and multifocal transcranial electric stimulation, could manipulate the placebo response by modulating the activity and excitability of its neural correlates. To identify potential stimulation targets, we conducted a meta-analysis to investigate placebo-associated regions in healthy volunteers, including studies with emotional components and painful stimuli. Using biophysical modeling, we identified NIBS solutions to manipulate placebo effects by targeting either a single key region or multiple connected areas. Moving to a network-oriented approach, we then ran a quantitative network mapping analysis on the functional connectivity profile of clusters emerging from the meta-analysis. As a result, we suggest a multielectrode optimized montage engaging the connectivity patterns of placebo-associated functional brain networks. These NIBS solutions hope to provide a starting point to actively control, modulate or enhance placebo effects in future clinical studies and cognitive enhancement studies.

Sex differences in associations between delay discounting and expectancies for alcohol analgesia

Self-medication of pain with alcohol is prevalent, and expectancies for alcohol analgesia likely influence pain relief and alcohol consumption. Hazardous alcohol use has been associated with greater delay discounting rates; however, little is known about the relationship between delay discounting and expectancies for alcohol analgesia. Therefore, the present study examined sex differences in associations between delay discounting and expectancies for alcohol analgesia. Healthy drinkers without chronic pain (N = 53) completed measures of expectancies for alcohol analgesia, alcohol use, and alcohol outcome expectancies. A five-trial adjusting-delay discounting task (DDT) for monetary outcomes was also administered. Regression analyses revealed that sex moderated the relationship between delay discounting and expectancies for alcohol analgesia. Steeper delay discounting rates were associated with weaker expectancies for alcohol analgesia among men when adjusting for average alcohol consumption. Among women, nonsignificant associations between delay discounting rates and expectancies for alcohol analgesia were observed. These findings provide initial evidence of sex differences in associations between delay discounting and expectancies for alcohol analgesia. The directionality of these associations was unexpected and may have implications for patterns of self-medication with alcohol. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Safety and efficacy of filgotinib, lanraplenib and tirabrutinib in Sjögren's syndrome: a randomized, phase 2, double-blind, placebo-controlled study

OBJECTIVE

The aim of this study was to characterize the safety and efficacy of filgotinib, lanraplenib and tirabrutinib in patients with active SS.

METHODS

This multicentre, double-blind study randomized patients with active primary or secondary SS [EULAR SS disease activity index (ESSDAI) ≥5) to receive filgotinib 200 mg (Janus kinase-1 inhibitor), lanraplenib 30 mg (spleen tyrosine kinase inhibitor), tirabrutinib 40 mg (Bruton's tyrosine kinase inhibitor), or placebo. The composite primary end point was the week-12 proportion of patients fulfilling protocol-specified improvement criteria (based on CRP and SS-related symptoms). The EULAR SS patient-reported index (ESSPRI) and the ESSDAI change from baseline (CFB) were secondary end points. Exploratory end points included disease-related biomarkers. Treatment-emergent adverse events (AEs) represented safety outcomes.

RESULTS

The mean of the baseline ESSDAI was 10.1, and of ESSPRI was 6.2 in the 150 patients who were treated; 125 completed the 24-week placebo-controlled treatment period. At week 12, 43.3% of the filgotinib group achieved the primary end point (P = 0.17 vs placebo) vs 42.3% (P = 0.16), 34.7% (P = 0.33), and 26.7% of lanraplenib, tirabrutinib, and placebo groups, respectively. Neither secondary end point was met. Biomarker reductions included immunoglobulins classically associated with SS disease activity. Filgotinib ESSDAI CFB appeared more pronounced in subgroups with baseline ESSDAI ≥14 or without DMARDs/CSs. Most AEs were Grade 1 or 2.

CONCLUSION

Three drugs with disparate mechanisms were tested, but no significant differences vs placebo in primary or secondary end points were observed. These results may be considered hypothesis-generating, given the drug tolerability, subgroup analysis, and biomarker findings.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03100942.

Exploring the role of expectancy in older US participants' response to an accelerated resolution therapy intervention for prolonged grief disorder

Accelerated resolution therapy (ART) is a psychotherapy for the treatment of prolonged grief disorder (PGD) defined as severe, enduring longing for the lost person. Currently, ART lacks examination of intrapersonal processes, like expectancy, as behavioural mechanisms for action. Therefore, the purpose of this paper was to present the findings on participants' treatment expectations of ART for PGD and then discuss potential hypotheses for future testing. This study was a primary qualitative descriptive analysis of prospectively collected interview data (collected 2017-2019) accrued as part of a randomised, wait-list controlled clinical trial in bereaved hospice family caregivers in the United States. The sample included 29 former informal caregivers who were at least 1-year post death of their care recipient. They were primarily female, older (67.4 ± 7.1 years), and a little over half (n = 18) had been married to their care recipient. Thematic analysis resulted in three distinct themes with six sub-themes: The role of knowledge in expectations (sub-themes uncertainty, prior knowledge); The role of personality in expectations (sub-themes openness, positive affect); and Expecting a process (sub-themes cognitive processes, affective processes) which described the interaction of person and process in shaping expectations of our intervention. An across theme analysis of the specificity of the participants' expectations uncovered that knowledge and personality inform expectations of ART and that individuals who verbalise a process for recovery tend to be very specific in their expectations. Three hypotheses for testing are put forward and implications for practice, research and policy discussed.

Why context matters when changing the diet: A narrative review of placebo, nocebo, and psychosocial context effects and implications for outcome research and nutrition counselling

Placebo (PE) and nocebo effects (NE) have been subjects of systematic research in medicine and psychotherapy for many decades to distinguish between the (specific) pharmacological effect of medication and the (unspecific) effect of the context. Despite this significant research, the awareness, operationalisation, and reflection of the multiplicity of PE, NE, and psychosocial context effects (PSCE) is currently limited when researching outcomes of diet changes in studies without randomisation and placebo control. This neglection is critical as it could systematically influence outcomes by moderating and mediating them and thus reducing the validity and evidence base of these studies. Therefore, we performed a (non-systematic) narrative review (NR) on the following objectives: (1) present a concise overview about the relevance of PE, NE, and PSCE in medicine and nutrition research; (2) review the current state of research on reflecting context effects when studying diet changes; (3) provide useful theoretical foundations via consideration and integration of micro- and macro context effects; (4) operationalise as hypotheses the potential PE, NE, and PSCE which are specific for researching diet changes; and (5) derive their impact for future research as well as for nutrition counselling. The electronic search in this NR for objective (2) identified N = 5 publications and for objective (4) we found N = 61 articles retrieved in the first round of search, additional references were identified by a manual and snowball search among the cited references resulting finally in N = 37. This NR offers a synoptical basis to foster awareness and operationalisation of a variety of PE, NE, and PSCE. Interdisciplinary research teams should monitor these factors using, e.g., qualitative, mixed-method studies, process evaluation, item bank approaches, moderator and mediator analysis that might reveal substantially new insights, and outcomes of relevance to science and nutrition counselling. Nevertheless, the present NR has several limitations, especially as it is non-systematic, because it is a very heterogeneous field of research, in which the topic we are investigating is usually regarded as marginal and subordinate. Therefore, future research should conduct systematic reviews and particularly theory-based primary studies (experimental research) on hypotheses of PE, NE, and PSCE in outcome research in diet changes.

Review of the scientific evidence on the individual sensitivity to electromagnetic fields (EHS)

Part of the population considers themselves as sensitive to the man-made electromagnetic radiation (EMF) emitted by powerlines, electric wiring, electric home appliance and the wireless communication devices and networks. Sensitivity is characterized by a broad variety of non-specific symptoms that the sensitive people claim to experience when exposed to EMF. While the experienced symptoms are currently considered as a real life impairment, the factor causing these symptoms remains unclear. So far, scientists were unable to find causality link between symptoms experienced by sensitive persons and the exposures to EMF. However, as presented in this review, the executed to-date scientific studies, examining sensitivity to EMF, are of poor quality to find the link between EMF exposures and sensitivity symptoms of some people. It is logical to consider that the sensitivity to EMF exists but the scientific methodology used to find it is of insufficient quality. It is time to drop out psychology driven provocation studies that ask about feelings-based non-specific symptoms experienced by volunteers under EMF exposure. Such research approach produces only subjective and therefore highly unreliable data that is insufficient to prove, or to disprove, causality link between EHS and EMF. There is a need for a new direction in studying sensitivity to EMF. The basis for it is the notion of a commonly known phenomenon of individual sensitivity, where individuals' responses to EMF depend on the genetic and epigenetic properties of the individual. It is proposed here that new studies, combining provocation approach, where volunteers are exposed to EMF, and high-throughput technologies of transcriptomics and proteomics are used to generate objective data, detecting molecular level biochemical responses of human body to EMF.

The reward for placebos: mechanisms underpinning placebo-induced effects on motor performance

Different from the most popular thinking, the placebo effect is not a purely psychological phenomenon. A body of knowledge from multidisciplinary fields has shown that the expectation of a potential benefit when receiving a treatment induces a cascade of neurochemical-electrophysiological alterations in brain reward areas, including motor-related ones. Alterations in the dopamine, opioid, and glutamate metabolism are the neural representation converting reward-derived declarative forms into an attractive and wanted behavior, thereby changing the activation in reward subcortical and cortical structures involved in motor planning, motor execution, and emotional-cognitive attributes of decision-making. We propose that the expectation of receiving a treatment that is beneficial to motor performance triggers a cascade of activations in brain reward areas that travels from motor planning and motor command areas, passing through corticospinal pathways until driving the skeletal muscles, therefore facilitating the motor performance. Although alternative explanations cannot be totally ruled out, this mechanistic route is robust in explaining the results of placebo-induced effects on motor performance and could lead to novel insights and applications in the exercise sciences. Factors such as sex differences in reward-related mechanisms and aversion-induced nocebo effects should also be addressed.

The effects of Transcranial Direct Current Stimulation on food craving and food intake in individuals affected by obesity and overweight: a mini review of the magnitude of the effects

Obesity represents one of the wellness diseases concurring to increase the incidence of diabetes, cardiovascular diseases, and cancer. One of the main perpetuating factors of obesity is food craving, which is characterized by an urgent desire to eat a large and various amount of food, regardless of calories requirement or satiety signals, and it might be addressed to the alteration of the dorsolateral prefrontal cortex (DLPFC) activity. Despite most of the gold-standard therapies focus on symptom treatment only, non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) could help treat overeating by modulating specific neural pathways. The current systematic review was conducted to identify whether convergent evidence supporting the usefulness of tDCS to deal with food craving are present in the literature. The review was conducted by searching articles published up to January 1^st 2022 on MEDLINE, Scopus and PsycInfo databases. We included studies investigating the effects of tDCS on food craving in subjects affected by overweight and obesity. According to eligibility criteria, 5 articles were included. Results showed that tDCS targeting left DLPFC with unipolar montage induced ameliorating effects on food craving. Controversial results were shown for the other studies, that might be ascribable to the use of bipolar montage, and the choice of other target areas. Further investigations including expectancy effect control, larger sample sizes and follow-up are needed to support more robust conclusions. To conclude, tDCS combined with the use of psychoeducative intervention, diet and physical activity, might represents a potential to manage food craving in individuals with overweight and obesity.

The Effects of Health Anxiety and Litigation Potential on Symptom Endorsement, Cognitive Performance, and Physiological Functioning in the Context of a Food and Drug Administration Drug Recall Announcement

Drug recalls and lawsuits against pharmaceutical manufacturers are accompanied by announcements emphasizing harmful drug side-effects. Those with elevated health anxiety may be more reactive to such announcements. We evaluated whether health anxiety and financial incentives affect subjective symptom endorsement, and objective outcomes of cognitive and physiological functioning during a mock drug recall. Hundred and sixty-one participants reported use of over-the-counter pain medications and presented with a fictitious medication recall via a mock Food and Drug Administration (FDA) website. The opportunity to join a class-action lawsuit was manipulated. We assessed health anxiety, recalled drug usage, blood pressure, heart rate, and performance on a computerized Trail Making Test (TMT). Symptom endorsement was strongly predicted by health anxiety. When combined, three health anxiety measures explained 28.5% variance (Cohen’s d = 1.26). These effects remain strong after controlling for depression and anxiety. Litigation condition did not predict symptom endorsement. Blood pressure and heart rate were modestly predicted by health anxiety, but not by litigation condition. TMT performance was consistently predicted by health anxiety, with higher scores associated with poorer performance. Although there were no main effects for litigation, interactions consistently emerged for the TMT, with generally poorer performance for those with higher health anxiety in the non-litigation condition; whereas health anxiety was unrelated to performance for the litigation condition. All but one participant joined the litigation when given the opportunity, despite a healthy sample and minimal use of pain medication. Subsequent data from 67 individuals with no mention of the FDA scenario or litigation showed that health anxiety still significantly predicts symptom endorsement (12.6% variance), but the explained variance is less than half that obtained in the FDA scenario. The findings suggest that health anxiety plays a significant role in adverse symptom reporting, beyond anxiety or depression, and this effect is independent of the presence of the FDA recall. The lack of differences for health anxiety and symptom endorsement between litigation and non-litigation conditions rules out malingering. Although it is general practice in drug recalls to list potential adverse side effects caused by medications, this may elicit unintended symptom experiences and health anxious individuals may be more susceptible.

A four-month home-based tDCS study on patients with Alzheimer's disease

In the present open-label study, our first aim was to study the tolerability and feasibility of long-term treatment with transcranial direct current stimulation (tDCS) and the second aim was to measure whether the treatment led to cognitive improvement. Participants with AD used a tDCS home-treatment kit inducing a low current (2 mA) via two scalp electrodes 30 minutes daily for 4 months. A total of 8 participants were recruited. The treatment technique was manageable for the participants and their spouses, and no troublesome side effects were reported. No significant effects of treatment were found after 4 months.

Non-invasive brain stimulation and neuroenhancement

Attempts to enhance human memory and learning ability have a long tradition in science. This topic has recently gained substantial attention because of the increasing percentage of older individuals worldwide and the predicted rise of age-associated cognitive decline in brain functions. Transcranial brain stimulation methods, such as transcranial magnetic (TMS) and transcranial electric (tES) stimulation, have been extensively used in an effort to improve cognitive functions in humans. Here we summarize the available data on low-intensity tES for this purpose, in comparison to repetitive TMS and some pharmacological agents, such as caffeine and nicotine. There is no single area in the brain stimulation field in which only positive outcomes have been reported. For self-directed tES devices, how to restrict variability with regard to efficacy is an essential aspect of device design and function. As with any technique, reproducible outcomes depend on the equipment and how well this is matched to the experience and skill of the operator. For self-administered non-invasive brain stimulation, this requires device designs that rigorously incorporate human operator factors. The wide parameter space of non-invasive brain stimulation, including dose (e.g., duration, intensity (current density), number of repetitions), inclusion/exclusion (e.g., subject's age), and homeostatic effects, administration of tasks before and during stimulation, and, most importantly, placebo or nocebo effects, have to be taken into account. The outcomes of stimulation are expected to depend on these parameters and should be strictly controlled. The consensus among experts is that low-intensity tES is safe as long as tested and accepted protocols (including, for example, dose, inclusion/exclusion) are followed and devices are used which follow established engineering risk-management procedures. Devices and protocols that allow stimulation outside these parameters cannot claim to be "safe" where they are applying stimulation beyond that examined in published studies that also investigated potential side effects. Brain stimulation devices marketed for consumer use are distinct from medical devices because they do not make medical claims and are therefore not necessarily subject to the same level of regulation as medical devices (i.e., by government agencies tasked with regulating medical devices). Manufacturers must follow ethical and best practices in marketing tES stimulators, including not misleading users by referencing effects from human trials using devices and protocols not similar to theirs.

Experience with opioids does not modify the brain network involved in expectations of placebo analgesia

Placebo analgesia (PA) is defined as a psychobiological phenomenon triggered by the information surrounding an analgesic drug instead of its inherent pharmacological properties. PA is hypothesized to be formed through either verbal suggestions or conditioning. The present study aims at disentangling the neural correlates of expectations effects with or without conditioning through prior experience using the model of PA.

We addressed this question by recruiting two groups of individuals holding comparable verbally‐induced expectations regarding morphine analgesia but either (i) with or (ii) without prior experience with opioids. We then contrasted the two groups' neurocognitive response to acute heat‐pain induction following the injection of sham morphine using electroencephalography (EEG). Topographic ERP analyses of the N2 and P2 pain evoked potential components allowed to test the hypothesis that PA involves distinct neural networks when induced by expectations with or without prior experience.

First, we confirmed that the two groups showed corresponding expectations of morphine analgesia (Hedges' g_s < .4 positive control criteria, g_s = .37 observed difference), and that our intervention induced a medium‐sized PA (Hedges' g_av ≥ .5 positive control, g_av = .6 observed PA). We then tested our hypothesis on the recruitment of different PA‐associated brain networks in individuals with versus without prior experience with opioids and found no evidence for a topographic N2 and P2 ERP components difference between the two groups. Our results thus suggest that in the presence of verbally‐induced expectations, modifications in the PA‐associated brain activity by conditioning are either absent or very small.