Increasing uncertainty in CNS clinical trials: the role of placebo, nocebo, and Hawthorne effects

Using Digital Art and Attachment Priming in a Web-Based Serious Game to Reduce Pain and Social Disconnection in Individuals With Chronic Pain and Loneliness: Randomized Controlled Trial

Background

Arts engagement using virtual reality and serious games represent promising nonpharmacological self-management treatment approaches to chronic pain. This study is the first randomized controlled trial to explore the impact of a web-based serious game that simulated a visit to an art museum on pain and social disconnection among individuals living with chronic pain and loneliness.

Objective

This study aimed to test the joint and separate effects of exposure to digital art and attachment figure priming on pain and social disconnection among individuals living with chronic pain and loneliness.

Methods

This randomized controlled trial used a 2 (digital artwork present and absent) × 2 (secure attachment and avoidant attachment prime) repeated measures factorial web-based experimental design with a hanging control condition. Mediation and moderation analyses examined how feelings about the social world triggered by the artwork and frequency of museum visits impacted the effects of the interventions on pain and social disconnection.

Results

The results are based on 308 participants. Mean age of the participants was 42.78 (SD 13.11; range 18-76) years, and 60.2% (n=186) were women. Posttest pain was lower than pretest pain for the artwork present (P=.001) and absent (P=.001) conditions. Similarly, posttest pain was lower than pretest pain for the secure (P=.001) and avoidant (P=.001) attachment priming conditions. Relative to the control group, artwork present (P=.001) and absent (P=.01) conditions had decreased posttest pain. The secure (P=.001) and avoidant (P=.001) attachment priming conditions also had lower posttest pain scores relative to the control group. Moreover, social disconnection decreased from pre- to posttest for both the artwork present (P=.04) and the secure attachment priming (P=.002) conditions. Relative to the control group, posttest social disconnection was lower for the artwork present (P=.02) and secure attachment priming condition (P=.03). The artwork-secure attachment (P=.001) and artwork-avoidant attachment (P=.006) conditions had lower posttest pain scores compared with the control group. Social disconnection decreased from pre- to posttest for the artwork-secure attachment (P=.01) and no artwork-secure attachment (P=.05) conditions. Posttest social disconnection was lower for the artwork-secure attachment condition compared with the control group (P=.04). Positive feelings about the social world triggered by artwork exposure and frequency of museum visits in the last year played a mediating and moderating role in these effects. Positive feelings about the social world were associated with decreased pain (B=-.53) and social disconnection (B=-.25), and these effects operated on individuals exposed to digital artwork at low, medium, and high frequency of physical museum visits.

Conclusions

Relative to a control group, visiting a web-based art museum reliably decreased pain and social disconnection among individuals living with chronic pain and loneliness. Engaging with digital artwork that triggers positive feelings about the social world may mitigate the burden of chronic pain.

Differential neural activity predicts the long-term stability of the effects of positive and negative expectations on pain

Expectations modulating pain perception is a well-researched phenomenon, but less is known about the persistence of expectation effects over longer time-courses. In this preregistered study, we examined the persistence of positive (placebo) and negative (nocebo) expectation effects over one week and investigated whether neural activity on day 1 (fMRI) can predict the stability of these effects one week later (n = 41). We tested whether expectations were reflected in EEG oscillatory activity at the second measurement. Both positive and negative pain modulation effects persisted over the tested time-period and did not undergo extinction. Expectations of higher compared to lower pain led to larger theta-to-alpha EEG activity. Most interestingly, differential neural activity in fMRI was correlated with persistent expectations. Individual differences in the persistence of positive expectation effects were related to reduced amygdala activity and enhanced activity in the anterior insula and dorsolateral prefrontal cortex (DLPFC) during the first session. In contrast, persistence of negative expectation effects was predicted by enhanced thalamus activity. Our findings indicate relatively stable placebo and nocebo effects over longer time courses, but this persistence is based on different neural areas for positive and negative expectations.

The Power of a Good Word: Enhancing the Efficacy of Analgesics in Clinical Settings

INTRODUCTION

Communication between medical staff and patients about treatment efficacy elicits expectations of benefit and improves treatment outcomes. While demonstrated in multiple studies via different research methodologies, uniform communication protocols have not been adopted in clinical practice. Here, we summarize the results of two sister studies aimed at bridging this gap.

METHODS

Women undergoing C-section (study 1, randomized controlled trial) and patients undergoing general or otolaryngologic surgeries (study 2, control group design) were recruited and assigned to the "regular communication" (RC) or "enhanced communication" (EC) arms. The EC arm received positive information about treatment, while the RC arm received no such information. In both studies, the primary outcome was change in pain intensity; in study 2, an additional outcome was morphine consumption.

RESULTS

Eighty women successfully completed study 1, and 102 patients successfully completed study 2. In both studies, significant time*group interactions were observed (p < 0.001). The analgesic effect was virtually twice as large in the EC arm compared to the RC arm. In study 2, in the last two timepoints of assessment, participants in the EC arm also consumed fewer doses of opioids than participants in the RC arm (p < 0.001). No significant differences were found in vital signs.

CONCLUSIONS

We provide ecological evidence that positive information about treatment significantly decreases pain and opioid consumption during routine clinical care. This study and others could encourage healthcare providers to harness the powerful effects of patients' expectations of benefit to improve analgesics outcomes and, potentially, the outcomes of other symptoms.

Citrus supplementation in subjective cognitive decline: results of a 36-week, randomized, placebo-controlled trial

BACKGROUND

Developing interventions for older adults with subjective cognitive decline (SCD) has the potential to prevent dementia in this at-risk group. Preclinical models indicate that Citrus-derived phytochemicals could benefit cognition and inflammatory processes, but results from clinical trials are still preliminary. The aim of this study is to determine the effects of long-term supplementation with Citrus peel extract on cognitive performance and inflammation in individuals with SCD.

METHODS

Eighty participants were randomly assigned to active treatment (400 mg of Citrus peel extract containing 3.0 mg of naringenin and 0.1 mg of auraptene) or placebo at 1:1 ratio for 36 weeks. The primary endpoint was the change in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total score across the 36-week trial period. Other cognitive outcomes included tests and scales evaluating verbal memory, attention, executive and visuospatial functions, and memory concerns. The secondary endpoint was the change of interleukin-8 (IL-8) levels over the 36-week trial period in a subsample of 60 consecutive participants. An Intention-to-treat approach with generalized linear mixed models was used for data analysis.

RESULTS

The RBANS total score showed significant improvement in both Citrus peel extract and placebo groups at 36 weeks (p for time < .001, d = 0.36, p time x treatment = .910). Significant time effects were also found in cognitive domains of short- and long-term verbal memory (p < .001) and scales of subjective memory (p < .01), with no significant time x treatment interaction. The largest effect sizes were observed in verbal memory in the placebo group (d = 0.69 in short-term, and d = 0.78 in long-term verbal memory). Increased IL-8 levels were found at 36-week follow-up in both Citrus peel extract and placebo groups (p for time = .010, d = 0.21, p time x treatment = .772). Adverse events were balanced between groups.

CONCLUSIONS

In this randomized clinical trial, long-term Citrus peel extract supplementation did not show cognitive benefits over placebo in participants with SCD, possibly due to high placebo response. These findings might have specific implications for designing future nutraceutical trials in individuals experiencing SCD.

TRIAL REGISTRATION

The trial has been registered at the United States National Library of Medicine at the National Institutes of Health Registry of Clinical Trials under the code NCT04744922 on February 9th, 2021 ( https://www.

CLINICALTRIALS

gov/ct2/show/NCT04744922 ).

Placebo effects in neuropathic pain conditions

Management of neuropathic pain is exceptionally challenging and development of new drugs and ways to optimize treatment effects in clinical practice are needed. Over the last decade, some of the mechanisms underlying placebo effects have been elucidated and some of the insights have the potential to improve the treatment for neuropathic pain. Research suggests that the increasing placebo responses observed in randomized controlled trials (RCTs) for neuropathic pain pose challenges for the development and availability of new effective pain medications. In neuropathic pain, these placebo responses are typically not controlled for the natural history of pain and other confounding factors. Thus, our knowledge about the magnitude and mechanisms of placebo effects in neuropathic pain is sparse. A few mechanistic studies investigating placebo effects by controlling for natural history of pain have found large placebo analgesia effects in neuropathic pain. Psychological factors such as expectations and emotions play a substantial role in inducing the placebo effects. Here, we review placebo effects and the psychological and neurobiological mechanisms contributing to the placebo effects. The knowledge obtained from studies of placebo mechanisms can help improve the information that can be obtained from RCTs and potentially improve development of new pain medications and optimize treatment of neuropathic pain in clinical practice.

Placebo-related improvement with methylphenidate treatment in children with ADHD

Non-specific effects of methylphenidate treatment, including expectancy and regression to the mean effects, contribute to the overall effect of methylphenidate on attention-deficit/hyperactivity disorder (ADHD) symptoms. Knowledge on the extent to which non-specific effects contribute to the overall effect and whether regression to the mean explains part of the non-specific effects, is currently lacking. A double-blind, randomized, placebo-controlled, cross-over trial was used to compare parent and teacher ratings of child ADHD symptoms at baseline and during treatment with placebo and 5, 10, 15 and 20 mg of methylphenidate, twice daily. Participants were 5-13-year-old children with a DSM-5 diagnosis of ADHD (N = 45). The extent to which non-specific effects contributed to the effects of methylphenidate was determined by ADHD symptom reductions observed with placebo versus reductions observed with active doses of methylphenidate. The influence of regression to the mean was examined by estimating the contribution of baseline ADHD symptom severity to the effects observed with placebo treatment. Data were analyzed using multilevel analyses. We observed significant non-specific effects of methylphenidate for parent-rated ADHD symptoms, but not for teacher-rated symptoms. For parent reported hyperactive/impulsive symptoms, higher baseline symptoms predicted larger effects with placebo, indicating regression to the mean effects. For parent-reports, a significant part of the overall effect of methylphenidate treatment is explained by non-specific effects. Our findings stress the importance of taking non-specific effects into account when evaluating methylphenidate treatment, by including teacher-reports and using a double baseline assessment during titration. Comparing active medication with a placebo in the titration trial has the potential to identify non-specific effects.

Risk factors associated with nocebo effects: A review of reviews

Objective

This meta-review aims to identify and categorize the risk factors that are associated with nocebo effects. The nocebo effect can exert a negative impact on treatment outcomes and have detrimental outcomes on health. Learning more about its potential predictors and risk factors is a crucial step to mitigating it.

Methods

Literature review studies about the risk factors for nocebo effects were searched through five databases (PubMed, Scopus, The Cochrane Library, PsycINFO, and Embase) and through grey literature. Methodological validity and risk of bias were assessed. We conducted a thematic analysis of the results of the forty-three included reviews.

Results

We identified nine categories of risk factors: prior expectations and learning; socio-demographic characteristics; personality and individual differences; neurodegenerative conditions; inflammatory conditions; communication of information and patient-physician relationship; drug characteristics; setting; and self-awareness. We also highlighted the main biochemical and neurophysiological mechanisms underlying nocebo effects.

Conclusions

Nocebo effects arise from expectations of adverse symptoms, particularly when triggered by previous negative experiences. A trusting relationship with the treating physician and clear, tailored treatment instructions can act as protective factors against a nocebo effect. Clinical implications are discussed.

Neuropsychiatric Behavioral Assessments in Mice After Acute and Long-Term Treatments of Low-Intensity Pulsed Ultrasound

Introduction: To evaluate whether both acute and chronic low-intensity pulsed ultrasound (LIPUS) affect brain functions of healthy male and female mice. Methods: Ultrasound (frequency: 1.5 MHz; pulse: 1.0 kHz; spatial average temporal average (SATA) intensity: 25 mW/cm2; and pulse duty cycle: 20%) was applied at mouse head in acute test for 20 minutes, and in chronic experiment for consecutive 10 days, respectively. Behaviors were then evaluated. Results: Both acute and chronic LIPUS at 25 mW/cm2 exposure did not affect the abilities of movements, mating, social interaction, and anxiety-like behaviors in the male and female mice. However, physical restraint caused struggle-like behaviors and short-time memory deficits in chronic LIPUS groups in the male mice. Conclusion: LIPUS at 25 mW/cm2 itself does not affect brain functions, while physical restraint for LIPUS therapy elicits struggle-like behaviors in the male mice. An unbound helmet targeted with ultrasound intensity at 25-50 mW/cm2 is proposed for clinical brain disease therapy.

Blinding assessment in clinical trials of traditional Chinese medicine: Exploratory principles and protocol

As one of the key components of clinical trials, blinding, if successfully implemented, can help to mitigate the risks of implementation bias and measurement bias, consequently improving the validity and reliability of the trial results. However, successful blinding in clinical trials of traditional Chinese medicine (TCM) is hard to achieve, and the evaluation of blinding success through blinding assessment lacks established guidelines. Taking into account the challenges associated with blinding in the TCM field, here we present a framework for assessing blinding. Further, this study proposes a blinding assessment protocol for TCM clinical trials, building upon the framework and the existing methods. An assessment report checklist and an approach for evaluating the assessment results are presented based on the proposed protocol. It is anticipated that these improvements to blinding assessment will generate greater awareness among researchers, facilitate the standardization of blinding, and augment the blinding effectiveness. The use of this blinding assessment may further advance the quality and precision of TCM clinical trials and improve the accuracy of the trial results. The blinding assessment protocol will undergo continued optimization and refinement, drawing upon expert consensus and experience derived from clinical trials. Please cite this article as: Wang XC, Liu XY, Shi KL, Meng QG, Yu YF, Wang SY, Wang J, Qu C, Lei C, Yu XP. Blinding assessment in clinical trials of traditional Chinese medicine: Exploratory principles and protocol. J Integr Med. 2023; 21(6): 528-536.

Placebo and nocebo effects and mechanisms associated with pharmacological interventions: an umbrella review

OBJECTIVES

This review aimed to summarise the existing knowledge about placebo and nocebo effects associated with pharmacological interventions and their mechanisms.

DESIGN

Umbrella review, adopting the Assessment of Multiple Systematic Reviews 2 tool for critical appraisal.

DATA SOURCES

MEDLINE/PubMed, Scopus, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trial were searched in September 2022, without any time restriction, for systematic reviews, narrative reviews, original articles. Results were summarised through narrative synthesis, tables, 95% CI.

OUTCOME MEASURES

Mechanisms underlying placebo/nocebo effects and/or their effect sizes.

RESULTS

The databases search identified 372 studies, for a total of 158 312 participants, comprising 41 systematic reviews, 312 narrative reviews and 19 original articles. Seventy-three per cent of the examined systematic reviews were of high quality.Our findings revealed that mechanisms underlying placebo and/or nocebo effects have been characterised, at least in part, for: pain, non-noxious somatic sensation, Parkinson's disease, migraine, sleep disorders, intellectual disability, depression, anxiety, dementia, addiction, gynaecological disorders, attention-deficit hyperactivity disorder, immune and endocrine systems, cardiovascular and respiratory systems, gastrointestinal disorders, skin diseases, influenza and related vaccines, oncology, obesity, physical and cognitive performance. Their magnitude ranged from 0.08 to 2.01 (95% CI 0.37 to 0.89) for placebo effects and from 0.32 to 0.90 (95% CI 0.24 to 1.00) for nocebo effects.

CONCLUSIONS

This study provides a valuable tool for clinicians and researchers, identifying both results ready for clinical practice and gaps to address in the near future.

FUNDING

Università Cattolica del Sacro Cuore, Milan, Italy with the 'Finanziamento Ponte 2022' grant.

PROSPERO REGISTRATION NUMBER

CRD42023392281.

Changes of cerebral functional connectivity induced by foot reflexology in a RCT

Non-Pharmacological Interventions (NPIs) are increasingly being introduced into healthcare, but their mechanisms are unclear. In this study, 30 healthy participants received foot reflexology (FR) and sham massage, and went through a resting-state functional magnetic resonance imaging (rs-fMRI) to evaluate NPIs effect on brain. Rs-fMRI revealed an effect of both NPIs on functional connectivity with changes occurring in the default-mode network, the sensorimotor network and a Neural Network Correlates of Pain (NNCP-a newly discovered network showing great robustness). Even if no differences were found between FR and SM, this study allowed to report brain biomarkers of well-being as well as the safety of NPIs. In further research, it could be relevant to study it in patients to look for a true reflexology induced-effect dependent of patient reported outcomes. Overall, these findings enrich the understanding of the neural correlates of well-being experienced with NPIs and provided insight into the basis of the mechanisms of NPIs.

The effects of cannabidiol on worry and anxiety among high trait worriers: a double-blind, randomized placebo controlled trial

RATIONALE

Evidence suggests cannabidiol (CBD) displays broad therapeutic potential in the context of anxiety; however, no study has examined the effects of CBD on worry, a defining, cognitive feature of anxiety. Additionally, no study has examined the effects of an acute, single dose of CBD compared to repeated CBD administration.

OBJECTIVES

Within a sample of 63 individuals with elevated trait worry, the current study aimed to assess the effects of an empirically-derived high dose of CBD (i.e., 300mg) compared to a commercially-derived dose of CBD (i.e., 50mg) versus placebo on worry severity and anxiety symptoms after an acute dose and after a 2-week administration period.

RESULTS

Results indicated no effect of acute CBD dosing on worry severity or anxiety symptoms. Repeated CBD administration similarly did not impact worry severity; however, 300mg of CBD reduced anxiety symptoms across the 2-week administration period compared to placebo.

CONCLUSIONS

Taken together, these findings suggest 300mg of oral CBD does not attenuate cognitive symptoms of anxiety (i.e., worry), following both acute and repeated administration. Some evidence for repeated administration of 300mg on physical symptoms of anxiety was obtained. Findings from the current study suggest CBD's modest anxiolytic effects may be specific to the physical aspects of anxious arousal.

Placebo effects in osteoarthritis: implications for treatment and drug development

Osteoarthritis (OA) is the most common form of arthritis worldwide, affecting ~500 million people, yet there are no effective treatments to halt its progression. Without any structure-modifying agents, management of OA focuses on ameliorating pain and improving function. Treatment approaches typically have modest efficacy, and many patients have contraindications to recommended pharmacological treatments. Drug development for OA is hindered by the gradual and progressive nature of the disease and the targeting of established disease in clinical trials. Additionally, new medications for OA cannot receive regulatory approval without demonstrating improvements in both structure (pathological features of OA) and symptoms (reduced pain and/or improved function). In clinical trials, people with OA show high 'placebo responses', which hamper the ability to identify new effective treatments. Placebo responses refer to the individual variability in response to placebos given in the context of clinical trials and other settings. Placebo effects refer specifically to short-lasting improvements in symptoms that occur because of physiological changes. To mitigate the effects of the placebo phenomenon, we must first understand what it is, how it manifests, how to identify placebo responders in OA trials and how these insights can be used to improve clinical trials in OA. Leveraging placebo responses and effects in clinical practice might provide additional avenues to augment symptom management of OA.

Effects of Buprenorphine/Naloxone and Methadone on Depressive Symptoms in People with Prescription Opioid Use Disorder: A Pragmatic Randomised Controlled Trial

OBJECTIVE

This study aimed to evaluate the effectiveness of flexible take-home dosing of buprenorphine/naloxone (BUP/NX) and methadone standard model of care in reducing depressive symptoms in people with prescription-type opioid use disorder (POUD). This trial also evaluated whether improvements in depressive symptoms were mediated by opioid use.

METHODS

Analyzed data came from the OPTIMA study (clinicaltrials.gov identifier: NCT03033732), a pragmatic randomised controlled trial comparing flexible take-home dosing of BUP/NX and methadone standard model of care for reducing opioid use in people with POUD. A total of 272 participants were recruited in four Canadian provinces. Participants were randomised 1:1 to BUP/NX or methadone. After treatment induction, past two-week opioid use was measured using the Timeline Followback every two weeks for a total of 24 weeks. Depressive symptoms were measured with the Beck Depression Inventory at baseline, weeks 12 and 24.

RESULTS

Both BUP/NX and methadone significantly reduced depressive symptoms at week 12 (aβ ± SE = -3.167 ± 1.233; P < 0.001) and week 24 (aβ ± SE = -7.280 ± 1.285; P < 0.001), with no interaction between type of treatment and time (P = 0.284). Improvements in depressive symptoms were only partially mediated by a reduction in opioid use (proportion mediated = 36.8%; 95% confidence interval = -1.158 to -0.070; P = 0.015).

CONCLUSIONS

BUP/NX and methadone showed similar effectiveness in decreasing comorbid depressive symptoms in people with POUD. This effect was partially explained by a reduction in opioid use. As both treatments seem equally effective, clinicians are encouraged to tailor the selection of OAT to patients' needs and characteristics.

Clinical trials for cognition in Parkinson's disease: Where are we and how can we do better?

BACKGROUND

Cognitive impairment is common in Parkinson's disease (PD) and has a substantial impact on quality of life. Despite numerous trials targeting various PD features, we still lack effective treatments for cognition beyond cholinesterase inhibitors.

OBJECTIVE

To identify the gaps in recent clinical trials with cognitive outcomes in PD and consider areas for improvement.

METHODS

We examined recent clinical trials with cognitive outcomes in PD registered on ClinicalTrials.gov, excluding trials without cognitive outcomes, non-interventional studies, and in atypical Parkinsonian disorders. Included trials were categorized by treatment approach (investigational medicinal product, behavioral, physical activity, device-based). Details of trial design and outcomes were collected.

RESULTS

178 trials at different stages of trial completion were considered. 46 trials were completed, 25 had available results. Mean follow-up duration was 29.9 weeks. Most common cognitive measure was Montreal Cognitive Assessment. Most were performed in North America or Europe. Majority of the participants identified as non-Hispanic and White. Only eight trials showed improvement in cognition, none showed improvement beyond four months. These included trials of international medicinal products, cognitive and physical interventions and devices. GRADE certainty levels ranged from Moderate to Very Low. Only mevidalen had a Moderate certainty for potential clinical effectiveness.

CONCLUSIONS

Amongst a large number of trials for cognition in PD, only a small proportion were completed. Few showed significant improvement, with no proven long-lasting effects. Trial design, lack of enrichment for at-risk groups, short follow-up duration, insensitive outcome measures likely contribute to lack of detectable benefit and should be considered in future trials.

The Biology of Placebo and Nocebo Effects on Experimental and Chronic Pain: State of the Art

(1) Background: In recent years, placebo and nocebo effects have been extensively documented in different medical conditions, including pain. The scientific literature has provided strong evidence of how the psychosocial context accompanying the treatment administration can influence the therapeutic outcome positively (placebo effects) or negatively (nocebo effects). (2) Methods: This state-of-the-art paper aims to provide an updated overview of placebo and nocebo effects on pain. (3) Results: The most common study designs, the psychological mechanisms, and neurobiological/genetic determinants of these phenomena are discussed, focusing on the differences between positive and negative context effects on pain in experimental settings on healthy volunteers and in clinical settings on chronic pain patients. Finally, the last section describes the implications for clinical and research practice to maximize the medical and scientific routine and correctly interpret the results of research studies on placebo and nocebo effects. (4) Conclusions: While studies on healthy participants seem consistent and provide a clear picture of how the brain reacts to the context, there are no unique results of the occurrence and magnitude of placebo and nocebo effects in chronic pain patients, mainly due to the heterogeneity of pain. This opens up the need for future studies on the topic.

Why a clinical trial is as good as its outcome measure: A framework for the selection and use of cognitive outcome measures for clinical trials of Alzheimer's disease

A crucial aspect of any clinical trial is using the right outcome measure to assess treatment efficacy. Compared to the rapidly evolved understanding and measurement of pathophysiology in preclinical and early symptomatic stages of Alzheimer's disease (AD), relatively less progress has been made in the evolution of clinical outcome assessments (COAs) for those stages. The current paper aims to provide a benchmark for the design and evaluation of COAs for use in early AD trials. We discuss lessons learned on capturing cognitive changes in predementia stages of AD, including challenges when validating novel COAs for those early stages and necessary evidence for their implementation in clinical trials. Moving forward, we propose a multi-step framework to advance the use of more effective COAs to assess clinically meaningful changes in early AD, which will hopefully contribute to the much-needed consensus around more appropriate outcome measures to assess clinical efficacy of putative treatments. HIGHLIGHTS: We discuss lessons learned on capturing cognitive changes in predementia stages of AD. We propose a framework for the design and evaluation of performance based cognitive tests for use in early AD trials. We provide recommendations to facilitate the implementation of more effective cognitive outcome measures in AD trials.

Therapeutic Misestimation in Patients with Degenerative Ataxia: Lessons from a Randomized Controlled Trial

BACKGROUND

The absence of effective treatments may render patients with degenerative cerebellar ataxias susceptible to a placebo response, which could affect the outcome of clinical trials.

OBJECTIVE

To retrospectively examine expectations of benefit in participants of an ataxia trial and identify determinants of possible therapeutic misestimation.

METHODS

Individuals with spinocerebellar ataxia type 3 who participated in a randomized, double-blind, sham-controlled trial received a custom-designed questionnaire about short-term and long-term treatment expectations, allocation preferences, and interpretation of treatment arm assignment based on the presence or absence of clinical improvement. To evaluate whether expectations were specifically related to the application of cerebellar transcranial direct current stimulation (tDCS) or more generally reflect an overly positive attitude of patients with ataxia toward trial participation and results, the last questions involved a hypothetical scenario in which an oral drug was tested against placebo with an aim identical to that of our tDCS study.

RESULTS

All 20 trial participants completed the questionnaire. If allocated to the active treatment arm, 75% of patients expected short-term health benefits and 55% thought they would still have less severe ataxia at 1-year follow-up compared with baseline. After 2 weeks, an average reduction in ataxia severity of 31.5% (standard deviation, 22.2%) was anticipated. Conversely, 65% associated a lack of improvement with probable or definite allocation to the placebo group. High expectations of benefit were neither related to the type of intervention nor to clinical or demographic characteristics.

CONCLUSION

Therapeutic misestimation is common in patients with degenerative ataxia and requires special attention in future trials. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Acupuncture and acupressure with improved cancer-related depression of retrospective studies

Introduction

Acupuncture and acupressure are widely used for treating cancer pain and depression and recognized as safe and effective by the international medical community. In this study, we systematically evaluated the efficacy, safety, and clinical significance of acupuncture and acupressure in treating cancer-related depression.

Methods

We searched MEDLINE, PubMed, Science Direct, Google Scholar, Web of Science and Embase and Chinese-language databases for randomized clinical trials (RCTs). To assess efficacy, rating scales administered by clinicians or experts were preferred, including the Hamilton Depression Rating Scale (HAMD), Self-rating Depression Scale (SDS), Self-rating Anxiety Scale (SAS), and Quality of Life Questionnaire-Core 30 (QLQ-C30) and the total effective rate after treatment. In all, Sixteen RCTs involving 1019 cancer patients were included in the Meta-analysis.

Results

Eleven (69%) of these studies reported the post-treatment total effective rate. Three hundred fifty-three patients received antidepressants; the total effective rate was 72.5%. Three hundred sixty-one patients underwent acupuncture and acupressure; the total effective rate was 90%. Meta-analysis results showed I² = 0%, no heterogeneity, (Z = 5.84, p < 0.00001); and combined OR = 3.55, (95% CI = 2.32 to 5.43).

Discussion

This study found that acupuncture and acupressure are as effective as medication in the treatment of cancer-related depression, provide a reliable basis for the clinical use of acupuncture to treat cancer-related depression, help promote nonpharmacological treatment for cancer-related complications. These approaches thus help reduce drug resistance and adverse reactions and improve patients' quality of life.

Immune Checkpoint Inhibitors Do Not Increase Short-Term Risk of Hypertension in Cancer Patients: a Systematic Literature Review and Meta-Analysis

Background:

Immune checkpoint inhibitors (ICIs) are becoming widely used for novel cancer treatments. Immune-related adverse events, including cardiac toxicity, are frequently observed following immune checkpoint inhibitor (ICI) use. However, little is known regarding the association between ICIs initiation and hypertension in cancer patients.

Methods:

A systematic literature search was performed using PubMed, EMBASE, Cochrane Library, and Web of Science Core Collection. The risk of hypertension associated with ICI initiation in randomized controlled trials (RCTs) was evaluated. Hypertension was categorized according to the Common Terminology Criteria for Adverse Events. The odds ratios of grades I to V and grades III to V hypertension were calculated using a random-effects meta-analysis.

Results:

Thirty-two RCTs (n=19 810 cancer patients) were included. At a median follow-up of 36 months, the median overall survival was 15 months in the ICI group. ICI initiation was not significantly associated with hypertension (grades I–V: odds ratio, 1.12 [95% CI, 0.96–1.30]; grades III–V: odds ratio, 0.95 [95% CI, 0.78–1.16]). Additionally, no significant differences in hypertension risk were evident in ICI combination therapies with various drugs, including anti-VEGF (vascular endothelial growth factor) agents. In a subgroup analysis based on clinical setting (placebo RCT versus nonplacebo RCT), there were discrepancies between the results obtained with different methodologies, with patients in the nonplacebo RCTs having higher grades I–V hypertension (I 2 =88.6%, P for heterogeneity=0.003).

Conclusions:

ICI initiation was not associated with short-term risk of hypertension in cancer patients, and the association was similar regardless of concomitant treatment with other anticancer drugs.

Differences between experimental and placebo arms in manual therapy trials: a methodological review

BACKGROUND

To measure the specific effectiveness of a given treatment in a randomised controlled trial, the intervention and control groups have to be similar in all factors not distinctive to the experimental treatment. The similarity of these non-specific factors can be defined as an equality assumption. The purpose of this review was to evaluate the equality assumptions in manual therapy trials.

METHODS

Relevant studies were identified through the following databases: EMBASE, MEDLINE, SCOPUS, WEB OF SCIENCE, Scholar Google, clinicaltrial.gov, the Cochrane Library, chiloras/MANTIS, PubMed Europe, Allied and Complementary Medicine (AMED), Physiotherapy Evidence Database (PEDro) and Sciencedirect. Studies investigating the effect of any manual intervention compared to at least one type of manual control were included. Data extraction and qualitative assessment were carried out independently by four reviewers, and the summary of results was reported following the PRISMA statement.

RESULT

Out of 108,903 retrieved studies, 311, enrolling a total of 17,308 patients, were included and divided into eight manual therapy trials categories. Equality assumption elements were grouped in three macro areas: patient-related, context-related and practitioner-related items. Results showed good quality in the reporting of context-related equality assumption items, potentially because largely included in pre-existent guidelines. There was a general lack of attention to the patient- and practitioner-related equality assumption items.

CONCLUSION

Our results showed that the similarity between experimental and sham interventions is limited, affecting, therefore, the strength of the evidence. Based on the results, methodological aspects for planning future trials were discussed and recommendations to control for equality assumption were provided.

Consideration in Randomized Placebo-Controlled Trial on Neck Pain to Avoid the Placebo Effect in Analgesic Action

Background: In neck pain treatment, many therapies are focused on etiology, while it is well-known that placebo analgesia is also present in these therapies. The specific efficacy for etiology may be underestimated by ignoring their actual placebo effect. In this study, a logistic regression analysis is used to explore the risk factors causing different placebo responses in patients with neck pain among two RCTs. The probability of the placebo effect is predicted based on these risk factors.

Methods: Trial A and Trial B were similarly designed, randomized, double-/single-blind, placebo-controlled trials in patients treating neck pain with Qishe pill or Shi-style manipulation. Both studies set a placebo pill twice a day or traction for every other day as control. For further analyses on the placebo effect in neck pain management, logistic regression was used to assess subgroup-placebo interactions. The odds ratio assessed a significant influence on the placebo effect.

Results: In this pooled analysis, the total number of patients recruited for these two studies was 284, of which 162 patients received placebo treatment (placebo drug or traction for every other day). No statistically significant differences are found at baseline between the participants with placebo effect and non-placebo effect in the gender, age, and disease duration except in VAS and NDI at the initial time. There are numerically more patients with placebo effect in the shorter disease duration subgroup (< 4 months [76%]), higher initial VAS subgroup (>60 mm [90%]), and worse initial NDI subgroup (>24 [72%]) compared with the gender and age subgroup. An ROC curve is established to assess the model-data fit, which shows an area under the curve of 0.755 and a 95% confidence interval of 0.677–0.830. Participants who show placebo effect after 2 weeks have significantly lower VAS scores after 4 weeks, while there is no significant difference in NDI improvement between the two groups after 4 weeks.

Conclusion: Neck pain patients with shorter disease duration are more likely to overscore their pain severity, because of their less experience in pain perception, tolerance, and analgesia expectation.

[Psychosocial factors in pain and pain management : A statement]

Although psychosocial factors have a profound impact on the experience of pain and pain recovery, the transfer to clinical application has so far been insufficient. With this article, a task force of the special interest group "Psychosocial Aspects of Pain" of the German Pain Society (Deutsche Schmerzgesellschaft e. V.) would like to draw attention to the considerable discrepancy between existing scientific evidence on the importance of psychosocial factors in the development of chronic pain disorders and the translation of these findings into the care of pain patients. Our objective is a stronger integration of psychological and psychosomatic expertise in pain treatment and research, as well as the improvement of structural and institutional conditions, to achieve an increased consideration of psychosocial aspects. In this way, modern, integrative and complex pain concepts can reach the patient. Based on these fundamental findings on the importance of psychosocial factors in pain and pain treatment, implications for the transfer to clinic and further research will be shown.

Behavioural intervention in medication overuse headache: a concealed double‐blind randomised controlled trial a concealed double‐blind randomised controlled trial a concealed double‐blind randomised controlled trial

Background and purpose

Medication overuse headache is a prevalent disorder, with a strong biobehavioural component. Hence, behavioural interventions might effectuate reduction of the overused medication. We assessed in a double‐blind manner the efficacy of a behavioural intervention during medication withdrawal therapy.

Methods

In this concealed, double‐blind, randomized controlled trial in medication overuse headache, conducted at the Leiden University Medical Centre, we compared the effect of maximal versus minimal behavioural intervention by a headache nurse during withdrawal therapy. Maximal intervention consisted of an intensive contact schedule, comprising education, motivational interviewing, and value‐based activity planning during 12 weeks of withdrawal therapy. Minimal intervention consisted of a short contact only. Patients were unaware of the existence of these treatment arms, as the trial was concealed in another trial investigating botulinum toxin A. Endpoints were successful withdrawal and monthly days of acute medication use after the withdrawal period.

Results

We enrolled 179 patients (90 maximal, 89 minimal intervention). At Week 12, most patients achieved withdrawal in both groups (82/90 [93%] maximal intervention vs. 75/89 [86%] minimal intervention, odds ratio = 2.44, 95% confidence interval [CI] = 0.83–7.23, p = 0.107). At Week 24, patients in the maximal intervention group had fewer medication days (mean difference = −2.23, 95% CI = −3.76 to −0.70, p = 0.005). This difference receded over time. Change in monthly migraine days did not differ between groups (−6.75 vs. −6.22).

Conclusions

This trial suggests modest benefit of behavioural intervention by a headache nurse during withdrawal therapy for medication overuse headache, to reduce acute medication use during and shortly after intervention, but extension seems warranted for a prolonged effect

Treatment-resistant depression: therapeutic options when first-line treatments fail

The Cochrane review by Davies et al aimed to address the lack of clarity on the risks and benefits of switching and augmentation strategies in the pharmacological treatment of treatment-resistant depression in adults who did not respond (or partially responded) to at least 4 weeks of antidepressant treatment at a recommended dose. This commentary assesses their review and their conclusion that augmenting the current antidepressant with mianserin or with an antipsychotic improves depressive symptoms over the short-term (8 to 12 weeks). Their results need to be treated with caution owing to the small body of evidence and individual comparisons supported by one, two or three studies, the limited evidence on long-term effects and the significant gaps in the literature (e.g. a lack of studies assessing dose increases).

What is the role of placebo in neurotherapeutics?

INTRODUCTION

The widespread use of the word 'placebo' in the medical literature emphasizes the importance of this phenomenon in modern biomedical sciences. Neuroscientific research over the past thirty years shows that placebo effects are genuine psychobiological events attributable to the overall therapeutic context, and can be robust in both laboratory and clinical settings.

AREAS COVERED

Here the authors describe the biological mechanisms and the clinical implications of placebo effects with particular emphasis on neurology and psychiatry, for example in pain, movement disorders, depression. In these conditions, a number of endogenous systems have been identified, such as endogenous opioids, endocannabinoids, and dopamine, which contribute to the placebo-induced benefit.

EXPERT OPINION

Every effort should be made to maximize the placebo effect and reduce its evil twin, the nocebo effect, in medical practice. This does not require the administration of a placebo, but rather the enhancement of the effects of pharmacological and nonpharmacological treatments through a good doctor-patient interaction.

Randomised methodology development study to investigate plaque removal efficacy of manual toothbrushes

OBJECTIVES

This study aimed to evaluate plaque removal efficacy of toothbrushes to guide clinical model development.

METHODS

This single-centre, randomised, controlled, examiner-blind, method development study included 80 healthy participants. Over 28 days, participants brushed twice-daily using a fluoride toothpaste and one of four marketed toothbrushes: Toothbrushes A (compact head) and B (regular head): medium-hard; flat trim; end-rounded bristles; Toothbrush C: medium-hard; end-rounded bristles; silky, tapered filaments; compact head; Toothbrush D: soft; tapered filaments; compact head. Supra-gingival plaque removal was evaluated immediately after single brushing events (Days 0, 7, 28, at study centre) and following 7- and 28-days' home use via Rustogi modified Navy Plaque Index (RPI) and Turesky modified Quigley Hein Plaque Index (TPI).

RESULTS

All toothbrushes provided significant plaque removal after single-brushing events with change from Day 0 pre-brushing scores on RPI ranging from -0.10 to -0.16 (p<.0001) and on TPI ranging from -0.61 to -0.89 (p<.0001). Toothbrushes A and B showed significant (p<.05) pre-brushing RPI/TPI plaque reductions after 7- (-0.04/-0.06, respectively for RPI; -0.16/-0.20, respectively for TPI) and 28-days (-0.04/-0.03, respectively for RPI; -0.20/-0.11, respectively for TPI) use versus Day 0 pre-brushing (except Toothbrush B, Day 28, non-significant TPI). There were no significant differences with Toothbrush C. Toothbrush D TPI was significantly lower at both timepoints versus Day 0 pre-brushing (p<.05). Study toothbrushes were generally well-tolerated.

CONCLUSION

The observations from this study showed how various aspects of a study design could impact toothbrushes performance. These data will inform the design of future clinical studies of plaque removal efficacy using manual toothbrushes.

CLINICAL SIGNIFICANCE STATEMENT

Regular effective oral hygiene can help prevent and treat gingivitis, principally via twice-daily mechanical cleaning with a toothbrush. Data generated from this methodology development study will help to identify the key aspects which impact toothbrushes' performance and understand which one would be more suitable to answer questions of scientific interest. This study provides useful information for the design of future clinical trials to assess plaque removal efficacy of manual toothbrushes and generate results to inform clinical recommendations.

A First Clinical Trial on Botulinum Toxin-A for Chronic Muscle-Related Pain in Cerebral Palsy

Objective: To test if botulinum toxin-A (BoNT-A) is effective in reducing chronic muscle-related pain in adults with spastic cerebral palsy (CP), as compared to placebo.

Design: A single-center, double-blind, parallel, randomized placebo-controlled trial. The design included an interim analysis to allow for confirmatory analysis, as well as pilot study outcomes.

Setting: Tertiary university hospital.

Participants: Adults with spastic CP and chronic pain associated with spastic muscle(s).

Intervention: Treatment was one session of electromyographically guided intramuscular injections of either BoNT-A or placebo normosaline.

Main Study Outcomes: The primary outcome was the proportion who achieved a reduction of pain intensity of two or more steps on the Numerical Rating Scale 6 weeks after treatment.

Results: Fifty individuals were screened for eligibility, of whom 16 were included (10 female, 6 male, mean age = 32 years, SD = 13.3 years). The randomization yielded eight participants per treatment arm, and all completed the study as randomized. The study was stopped at the interim analysis due to a low probability, under a preset threshold, of a positive primary outcome. Four individuals were treatment responders in the BoNT-A group for the primary outcome compared to five responders in the placebo group (p = 1.000). Adverse events were mild to moderate. In exploratory analysis, the BoNT-A group had a trend of continuing reduction of pain at the last follow-up, after the primary endpoint.

Conclusions: This study did not find evidence that BoNT-A was superior to placebo at the desired effect size (number needed to treat of 2.5) at 6 weeks after treatment.

Trial registration:ClinicalTrials.gov: NCT02434549

Treatment journey in rheumatoid arthritis with biosimilars: from better access to good disease control through cost savings and prevention of nocebo effects

Early diagnosis and treatment of rheumatoid arthritis (RA) are of critical importance to halt the progression of the disease. Optimal use of advanced imaging techniques or biomarkers may facilitate early diagnosis of RA. Even though many disease-modifying anti-rheumatic drugs (DMARDs) are available for RA treatment, biological DMARDs (bDMARDs) offer expanding therapeutic options and good outcomes in patients with RA who do not have a sufficient response to conventional synthetic DMARDs. However, high costs of bDMARDs have limited patient access to optimised disease management and increased the cost burden for healthcare systems. The advent of biosimilars led to significant cost savings driven by price competition among the reference products, which could be beneficial for healthcare systems. Healthcare provider (HCP)–patient communication and informed shared decision-making are crucial to prevent the occurrence of a nocebo effect, which results from negative perceptions that patients may have and could lead to less effective outcomes. Research has demonstrated that effective communication between HCPs and patients utilising positive framing can improve acceptance by patients to be initiated on or switched to a biosimilar and can help to integrate biosimilars into routine clinical practice to maximise benefits for patients with RA.

[Treatment expectations for postoperative pain]

Hintergrund

Präoperative Behandlungserwartungen haben einen deutlichen Einfluss auf die postoperativen Schmerzen und Behandlungsergebnisse. Positive Erwartungen sind ein wichtiger Mechanismus von Placeboeffekten und negative Erwartungen ein wichtiger Mechanismus von Noceboeffekten.

Fragestellung

Welchen Einfluss haben Behandlungserwartungen, wie werden diese im klinischen Setting erhoben und wie können diese Erkenntnisse in der klinischen Praxis umgesetzt werden?

Material und Methoden

Es wurde eine Literatursuche für klinische Studien mit den Schlagwörtern „expectation“ AND („postoperative“ OR „surgery“) durchgeführt. Ausgewählt wurden alle aktuellen englischen und deutschen Artikel. Zusätzlich wurden die Literaturverzeichnisse der gefundenen Artikel untersucht und mit aufgenommen.

Ergebnisse

Insgesamt 158 Artikel wurden gefunden, von denen 49 Artikel Erwartungen erheben und ein postoperatives Behandlungsergebnis einbeziehen. Die meisten Artikel untersuchen Erwartungen in der Baseline-Erhebung, um nachzuweisen, dass sich Gruppen in Gruppenvergleichen präoperativ nicht voneinander unterscheiden. Die Studien, die den Einfluss von Erwartungen prospektiv untersuchen, verwenden sehr unterschiedliche Messverfahren, um das Konstrukt „Erwartung“ zu erheben. Somit ist ein Vergleich zwischen den Studien schwer möglich. Es gibt wenige Studien, die untersuchen, ob und wie die Erwartungen perioperativ beeinflusst werden können, und die praxisrelevante Interventionen zu deren Veränderung entwickelt haben.

Schlussfolgerung

Für eine fundierte Untersuchung der Behandlungserwartung sollten in klinischen Studien valide und reliable Messverfahren verwendet werden. Weitere Studien sollten sich mit Interventionsmöglichkeiten auseinandersetzen, damit Behandlungserwartungen auch in die klinische Standardbehandlung einbezogen werden können.

Thirty Years of Neuroscientific Investigation of Placebo and Nocebo: The Interesting, the Good, and the Bad

Over the past 30 years there has been a surge of research on the placebo effect using a neuroscientific approach. The interesting aspects of this effort are related to the identification of several biological mechanisms of both the placebo and nocebo effects, the latter of which is defined as a negative placebo effect. Some important translational implications have emerged both in the setting of clinical trials and in routine medical practice. One of the principal contributions of neuroscience has been to draw the attention of the scientific and medical communities to the important role of psychobiological factors in therapeutic outcomes, be they drug related or not. Indeed, many biological mechanisms triggered by placebos and nocebos resemble those modulated by drugs, suggesting a possible interaction between psychological factors and drug action. Unfortunately, this new knowledge regarding placebos has the potential of being dangerously exploited by pseudoscience. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Attempting to Separate Placebo Effects from Exercise in Chronic Pain: A Systematic Review and Meta-analysis

BACKGROUND

Pain is the most disabling characteristic of musculoskeletal disorders, and while exercise is promoted as an important treatment modality for chronic musculoskeletal conditions, the relative contribution of the specific effects of exercise training, placebo effects and non-specific effects such as natural history are not clear. The aim of this systematic review and meta-analysis was to determine the relative contribution of these factors to better understand the true effect of exercise training for reducing pain in chronic primary musculoskeletal pain conditions.

DESIGN

Systematic review with meta-analysis DATA SOURCES: MEDLINE, CINAHL, SPORTDiscus, EMBASE and CENTRAL from inception to February 2021. Reference lists of prior systematic reviews.

ELIGIBILITY CRITERIA

Randomised controlled trials of interventions that used exercise training compared to placebo, true control or usual care in adults with chronic primary musculoskeletal pain. The review was registered prospectively with PROSPERO (CRD42019141096).

RESULTS

We identified 79 eligible trials for quantitative analysis. Pairwise meta-analysis showed very low-quality evidence (GRADE criteria) that exercise training was not more effective than placebo (g [95% CI]: 0.94 [- 0.17, 2.06], P = 0.098, I² = 92.46%, studies: n = 4). Exercise training was more effective than true, no intervention controls (g [95% CI]: 0.99 [0.66, 1.32], P < 0.001, I² = 92.43%, studies: n = 42), usual care controls (g [95% CI]: 0.64 [0.44, 0.83], P < 0.001, I² = 76.52%, studies: n = 33), and when all controls combined (g [95% CI]: 0.84 [0.64, 1.04], P < 0.001, I² = 90.02%, studies: n = 79).

CONCLUSIONS

There is very low-quality evidence that exercise training is not more effective than non-exercise placebo treatments in chronic pain. Exercise training and the associated clinical encounter are more effective than true control or standard medical care for reductions in pain for adults with chronic musculoskeletal pain, with very low quality of evidence based on GRADE criteria.

Placebo Response Reduction and Accurate Pain Reporting Training Reduces Placebo Responses in a Clinical Trial on Chronic Low Back Pain: Results From a Comparison to the Literature

OBJECTIVE

A literature review was conducted to compare placebo responses in a recent trial-which implemented an accurate pain reporting (APR) and placebo response reduction (PRR) training program-with placebo responses in similar previous trials in chronic lower back pain (CLBP) that did not use such training.

METHODS

A literature search was performed to find parallel design, randomized, controlled trials of pharmacological treatments administered orally or through intravenous injection for CLBP. Studies were assessed for the proportion of placebo responders, defined as the proportion of patients in the placebo group with ≥30% reduction in pain intensity. A χ analysis was performed on the proportion of responders from the SPRINT trial and from other similar studies.

RESULTS

Of 844 studies identified in the initial screening process, 16 studies were included for comparison. The percentage of placebo responders was statistically significantly lower in the SPRINT study (19.1%) compared with other CLBP trials (38.0%) (P=0.003). Our results show that the placebo response was lower in the SPRINT trial than other comparable studies on CLBP.

DISCUSSION

These findings are consistent with results from other studies showing that neutralizing subject and study staff expectations of therapeutic benefit can decrease the placebo response in clinical trials. The results of this study suggest training participants and staff to improve pain reporting accuracy, neutralize expectations, and decrease external cues that may bias participants' pain ratings in clinical trials may effectively decrease the placebo response leading to increased assay sensitivity.

Hypothalamic-Pituitary-Adrenal Activity in Adverse Events Reporting after Placebo Administration

Participants of clinical trials who receive a placebo treatment often report a variety of adverse events, sometimes called nocebo effects. The reason why these adverse events occur is not clear, and understanding the underlying mechanisms represents a challenge that is likely to improve the interpretation of clinical trials as well as medical practice. Here, we studied 192 healthy subjects who received placebo oxygen through a mask after reading (READ) or not reading (NO-READ) a list of possible adverse events of oxygen breathing: headache, chest pain, abdominal pain, and cough. The whole hypothalamus-pituitary-adrenal axis was assessed just before and right after placebo breathing by measuring the hypothalamic corticotropin-releasing hormone (CRH), pituitary adrenocorticotropic hormone (ACTH), and adrenal cortisol (COR). In addition, both state and trait anxiety were assessed. We found that 64.5% of the NO-READ group reported no adverse events, 30.2% had one, and only 5.2% had two adverse events. In contrast, only 20.8% of the READ group reported no adverse events, whereas 1, 2, 3, and 4 adverse events were reported with a frequency of 21.8%, 19.8%, 19.8%, and 17.7%, respectively. In addition, when the READ group reported three and four adverse events, CRH, ACTH, and COR were significantly increased compared to the NO-READ group, along with an increase in state anxiety scores. These data indicate that hypothalamic-pituitary-adrenal activity and state anxiety are increased in those subjects who report many adverse events after reading a list of adverse events, thus highlighting a possible neuroendocrine mechanism after placebo administration.

Placebo Response and Its Predictors in Attention Deficit Hyperactivity Disorder: A Meta-Analysis and Comparison of Meta-Regression and MetaForest

BACKGROUND

High placebo response in attention deficit hyperactivity disorder (ADHD) can reduce medication-placebo differences, jeopardizing the development of new medicines. This research aims to (1) determine placebo response in ADHD, (2) compare the accuracy of meta-regression and MetaForest in predicting placebo response, and (3) determine the covariates associated with placebo response.

METHODS

A systematic review with meta-analysis of randomized, placebo-controlled clinical trial investigating pharmacological interventions for ADHD was performed. Placebo response was defined as the change from baseline in ADHD symptom severity assessed according to the 18-item, clinician-rated, DSM-based rating scale. The effect of study design-, intervention-, and patient-related covariates in predicting placebo response was studied by means of meta-regression and MetaForest.

RESULTS

Ninety-four studies including 6614 patients randomized to placebo were analyzed. Overall, placebo response was -8.9 points, representing a 23.1% reduction in the severity of ADHD symptoms. Cross-validated accuracy metrics for meta-regression were R2 = 0.0012 and root mean squared error = 3.3219 for meta-regression and 0.0382 and 3.2599 for MetaForest. Placebo response among ADHD patients increased by 63% between 2001 and 2020 and was larger in the United States than in other regions of the world.

CONCLUSIONS

Strong placebo response was found in ADHD patients. Both meta-regression and MetaForest showed poor performance in predicting placebo response. ADHD symptom improvement with placebo has markedly increased over the last 2 decades and is greater in the United States than the rest of the world.

Expectations of Benefit in a Trial of a Candidate Disease-Modifying Treatment for Parkinson Disease

BACKGROUND

Expectations of benefit have an important therapeutic impact. How well study participants understand the concept of slowing disease progression and how their expectations of benefit are shaped in related clinical trials is not well known.

OBJECTIVE

We aimed to assess expectancy and treatment arm preference of participants in a disease-modification trial in Parkinson disease (PD).

METHODS

Participant expectations and treatment preference were assessed before treatment randomization in the SURE-PD3 trial (NCT02642393).

RESULTS

We included 297 PD patients (0.71 ± 0.67 years after diagnosis). Pre-randomization, 90% of participants expressed a preference for inosine (active treatment) allocation (n = 266/297), and 53% (n = 158) expected to be "somewhat" or "a lot better" in their symptoms over 2 years of treatment with inosine.

CONCLUSIONS

Participants of a disease-modification trial in PD had likely unrealistic expectations of benefit (ie, improvement in symptoms over years), which may affect clinical trial interpretation and calls for improved education in future disease-modification trials in PD. © 2021 International Parkinson and Movement Disorder Society.

Safety and efficacy of occipital nerve stimulation for attack prevention in medically intractable chronic cluster headache (ICON): a randomised, double-blind, multicentre, phase 3, electrical dose-controlled trial

BACKGROUND

Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish whether ONS could serve as an effective treatment for patients with MICCH.

METHODS

The ONS in MICCH (ICON) study is an investigator-initiated, international, multicentre, randomised, double-blind, phase 3, electrical dose-controlled clinical trial. The study took place at four hospitals in the Netherlands, one hospital in Belgium, one in Germany, and one in Hungary. After 12 weeks' baseline observation, patients with MICCH, at least four attacks per week, and history of being non-responsive to at least three standard preventive drugs, were randomly allocated (at a 1:1 ratio using a computer-generated permuted block) to 24 weeks of occipital nerve stimulation at either 100% or 30% of the individually determined range between paraesthesia threshold and near-discomfort (double-blind study phase). Because ONS causes paraesthesia, preventing masked comparison versus placebo, we compared high-intensity versus low-intensity ONS, which are hypothesised to cause similar paraesthesia, but with different efficacy. In weeks 25-48, participants received individually optimised open-label ONS. The primary outcome was the weekly mean attack frequency in weeks 21-24 compared with baseline across all patients and, if a decrease was shown, to show a group-wise difference. The trial is closed to recruitment (ClinicalTrials.gov NCT01151631).

FINDINGS

Patients were enrolled between Oct 12, 2010, and Dec 3, 2017. We enrolled 150 patients and randomly assigned 131 (87%) to treatment; 65 (50%) patients to 100% ONS and 66 (50%) to 30% ONS. One of the 66 patients assigned to 30% ONS was not implanted and was therefore excluded from the intention-to-treat analysis. Because the weekly mean attack frequencies at baseline were skewed (median 15·75; IQR 9·44 to 24·75) we used log transformation to analyse the data and medians to present the results. Median weekly mean attack frequencies in the total population decreased from baseline to 7·38 (2·50 to 18·50; p<0·0001) in weeks 21-24, a median change of -5·21 (-11·18 to -0·19; p<0·0001) attacks per week. In the 100% ONS stimulation group, mean attack frequency decreased from 17·58 (9·83 to 29·33) at baseline to 9·50 (3·00 to 21·25) at 21-24 weeks (median change from baseline -4·08, -11·92 to -0·25), and for the 30% ONS stimulation group, mean attack frequency decreased from 15·00 (9·25 to 22·33) to 6·75 (1·50 to 16·50; -6·50, -10·83 to -0·08). The difference in median weekly mean attack frequency between groups at the end of the masked phase in weeks 21-24 was -2·42 (95% CI -5·17 to 3·33). In the masked study phase, 129 adverse events occurred with 100% ONS and 95 occurred with 30% ONS. None of the adverse events was unexpected but 17 with 100% ONS and eight with 30% ONS were labelled as serious, given they required brief hospital admission for minor hardware-related issues. The most common adverse events were local pain, impaired wound healing, neck stiffness, and hardware damage.

INTERPRETATION

In patients with MICCH, both 100% ONS intensity and 30% ONS intensity substantially reduced attack frequency and were safe and well tolerated. Future research should focus on optimising stimulation protocols and disentangling the underlying mechanism of action.

FUNDING

The Netherlands Organisation for Scientific Research, the Dutch Ministry of Health, the NutsOhra Foundation from the Dutch Health Insurance Companies, and Medtronic.

Efficacy of an occluding toothpaste on dentinal hypersensitivity over 14 days

OBJECTIVES

To evaluate a 0.454% stannous fluoride/5% sodium tripolyphosphate (STP) toothpaste's ability to provide relief from dentinal hypersensitivity (DH) applied using 'focused brushing.'

MATERIALS AND METHODS

In two randomised, examiner-blind, parallel-group studies, a SnF₂/STP toothpaste was applied by brushing two selected sensitive teeth before 1 min whole-mouth brushing, compared to 1 min whole-mouth brushing only, with a negative control toothpaste. DH was assessed via evaporative (air) (Schiff scale) and tactile (Yeaple probe) stimuli after 7 and 14 d of twice-daily brushing.

RESULTS

In total, 141 (Study 1)/142 (Study 2) participants were randomised. In Study 1, the test treatment significantly reduced DH at 7/14 d versus baseline (7/14 d Schiff difference: -0.74 [-0.84,-0.65]/-1.39 [-1.54,-1.23]; tactile: 6.00 [4.88,7.13]/15.30 [13.34,17.26]); whereas the Control treatment did not (7/14 d Schiff difference -0.03 [-0.13,0.06]/-0.10 [-0.25,0.06]; tactile: 0.77 [-0.36,1.90]/0.77 [-1.20,2.74]). Differences between Test and Control were statistically significant (p < 0.0001 all cases). In Study 2, both treatments reduced DH compared to baseline by both measures, but there were no significant between-treatment differences. Toothpastes were generally well-tolerated.

DISCUSSION AND CONCLUSIONS

Previous studies and Study 1 support SnF₂/5% STP toothpaste efficacy; Study 2 results may have been influenced by placebo/Hawthorne effects. DH study design needs to, where possible, negate such effects.

What can be done to control the placebo response in clinical trials? A narrative review

The desire to reduce high placebo response rates in clinical trials is a popular concept. However, few studies have rigorously examined the effectiveness of methods to control for placebo responses that are relevant to randomized controlled trials. The primary objective of this review was to evaluate the effect of experimental placebo manipulations in randomized controlled trials (RCTs). We critically reviewed studies designed to manipulate placebo responses including positive expectations regarding the effectiveness of the placebo treatment, manipulating the time spent with subjects, and training study staff and subjects to accurately report symptom severity. These efforts have generally resulted in reduced placebo response and improved discrimination between drug and placebo. Interventions that neutralize staff and subject expectations and improve the ability of subjects to accurately report symptom severity have shown the most promise. Reduction of the placebo response has the potential to accelerate the development of new therapeutics.

Improvements in clinical signs of Parkinson's disease using photobiomodulation: a prospective proof-of-concept study

Background

Parkinson’s disease (PD) is a progressive neurodegenerative disease with no cure and few treatment options. Its incidence is increasing due to aging populations, longer disease duration and potentially as a COVID-19 sequela. Photobiomodulation (PBM) has been successfully used in animal models to reduce the signs of PD and to protect dopaminergic neurons.

Objective

To assess the effectiveness of PBM to mitigate clinical signs of PD in a prospective proof-of-concept study, using a combination of transcranial and remote treatment, in order to inform on best practice for a larger randomized placebo-controlled trial (RCT).

Methods

Twelve participants with idiopathic PD were recruited. Six were randomly chosen to begin 12 weeks of transcranial, intranasal, neck and abdominal PBM. The remaining 6 were waitlisted for 14 weeks before commencing the same treatment. After the 12-week treatment period, all participants were supplied with PBM devices to continue home treatment. Participants were assessed for mobility, fine motor skills, balance and cognition before treatment began, after 4 weeks of treatment, after 12 weeks of treatment and the end of the home treatment period. A Wilcoxon Signed Ranks test was used to assess treatment effectiveness at a significance level of 5%.

Results

Measures of mobility, cognition, dynamic balance and fine motor skill were significantly improved (p < 0.05) with PBM treatment for 12 weeks and up to one year. Many individual improvements were above the minimal clinically important difference, the threshold judged to be meaningful for participants. Individual improvements varied but many continued for up to one year with sustained home treatment. There was a demonstrable Hawthorne Effect that was below the treatment effect. No side effects of the treatment were observed.

Conclusions

PBM was shown to be a safe and potentially effective treatment for a range of clinical signs and symptoms of PD. Improvements were maintained for as long as treatment continued, for up to one year in a neurodegenerative disease where decline is typically expected. Home treatment of PD by the person themselves or with the help of a carer might be an effective therapy option. The results of this study indicate that a large RCT is warranted.

Trial registration

Australian New Zealand Clinical Trials Registry, registration number: ACTRN12618000038291p, registered on 12/01/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02248-y.

Expectancies as predictors of symptom improvement after antimicrobial therapy for persistent symptoms attributed to Lyme disease

INTRODUCTION/OBJECTIVE

Expectancies about symptom improvement or deterioration are reliable predictors of symptom progression and treatment outcomes (symptom resolution or symptomatic improvement) in many (non-)pharmacological studies and treatments. This study examined predictors of symptom improvement after antimicrobial therapy for persistent symptoms attributed to Lyme disease, hypothesizing particularly pre-treatment expectancies regarding symptom improvement to be predictive.

METHODS

A predictive study was performed on pre-treatment and post-treatment individual characteristics, including expectancies, and physical and mental health-related quality of life (HRQoL) from the PLEASE-trial comparing randomized 12-weeks of doxycycline, clarithromycin-hydroxychloroquine, or placebo following 2 weeks of intravenous ceftriaxone. At end-of-treatment (14 weeks after trial start) and follow-up (52 weeks), complete data of 231 and 170 (of initial 280) patients with persistent symptoms temporally related to a history of erythema migrans or otherwise confirmed symptomatic Lyme disease, or accompanied by B. burgdorferi IgG or IgM antibodies, were examined through hierarchical regression analyses.

RESULTS

In addition to pre-treatment HRQoL, pre-treatment expectancies regarding symptom improvement were consistently associated with stronger physical and mental HRQoL improvements at both end-of-treatment and follow-up (95% CI range: .09;.54, p < .01 to .27;.92, p < .001). Post-treatment expectancies regarding having received antibiotics vs. placebo was associated with more HRQoL improvement at end-of-treatment, but not at follow-up (95% CI-range 1.00;4.75, p = .003 to -7.34; -2.22, p < .001).

CONCLUSIONS

The present study shows that, next to pre-treatment functioning, patients' pre-treatment and post-treatment expectancies regarding improvement of persistent symptoms attributed to Lyme disease relate to a more beneficial symptom course. Expectancies of patients may be relevant to explain and potentially improve patient outcomes (e.g., by optimized communication about treatment success).

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01207739 (Registration date: 23-09-2010) Key Points • As there is currently no sufficient symptom resolution or symptomatic improvement for many patients with persistent symptoms attributed to Lyme disease, it is relevant to know which factors determine symptom progression and predict heterogeneity in treatment response. • Next to pre-treatment functioning, expectancies regarding symptom improvement and having received antimicrobial study medication are associated with a more beneficial symptom course after both shorter-term and longer-term antimicrobial treatment. • Expectancies are relevant to consider in treatment studies and may be useful in clinical settings to improve symptom course and treatment outcome (e.g., by optimized communication about treatment success).

Efficacy, safety and central nervous system effects after switch from efavirenz/tenofovir/emtricitabine to doravirine/tenofovir/lamivudine

OBJECTIVE

Doravirine is an alternative treatment option for individuals who do not tolerate efavirenz. We assessed efficacy, safety, and CNS effects in adults with HIV-1 and CNS complaints who switched from an efavirenz-based regimen to a doravirine-based regimen.

DESIGN

Multicenter, double-blind, randomized trial (NCT02652260).

METHODS

Virologically suppressed adults receiving efavirenz/emtricitabine/tenofovir (EFV/FTC/TDF), or its components, with ongoing EFV-associated CNS toxicity grade 2 or higher (DAIDS criteria) were switched to doravirine/lamivudine/tenofovir (DOR/3TC/TDF) on day 1 (Immediate Switch Group [ISG]) or after 12 weeks (Deferred Switch Group [DSG]). CNS toxicity data were collected by self-administered questionnaire. The primary endpoint was the proportion of participants with any grade 2 or higher CNS toxicity at week 12. Secondary endpoints included virologic response and effect on fasting lipids.

RESULTS

Eighty-six participants (58% men, 56% black, median age 41 years, median 4 years on prior EFV regimen) were enrolled (43 ISG, 43 DSG) and included in the analyses. At week 12, 42% of ISG and 37% of DSG had at least 1 grade 2 or higher CNS toxicity [difference 4.7%, 95% CI (-16 to 25%); P = 0.33]. At 24 weeks postswitch, HIV-1 RNA less than 50 copies/ml was maintained in 95.3% of participants, and fasting lipids were significantly decreased (LDL-cholesterol -11.0, non-HDL-cholesterol -13.2, HDL-cholesterol -7.7, total cholesterol -20.9, and triglycerides -13.0 mg/dl).

CONCLUSION

In participants who had CNS complaints while receiving EFV/FTC/TDF, improvement in CNS toxicities attributable to EFV was not significantly different after switching to DOR/3TC/TDF compared with remaining on EFV/FTC/TDF. Virologic efficacy was maintained and lipid profiles improved after switching to DOR/3TC/TDF.

Placebo response mitigation with a participant-focused psychoeducational procedure: a randomized, single-blind, all placebo study in major depressive and psychotic disorders

The remarkably high and growing placebo response rates in clinical trials for CNS indications, such as depression and schizophrenia, constitute a major challenge for the drug development enterprise. Despite extensive literature on participant expectancies and other potent psychosocial factors that perpetuate placebo response, no empirically validated participant-focused strategies to mitigate this phenomenon have been available. This study evaluated the efficacy of the Placebo-Control Reminder Script (PCRS), a brief interactive procedure that educates participants about factors known to cause placebo response, which was administered prior to the primary outcome assessments to subjects with major depressive or psychotic disorders who had at least moderate depression. Participants were informed they would participate in a 2-week randomized clinical trial with a 50% chance of receiving either an experimental antidepressant medication or placebo. In actuality, all participants received placebo. Participants randomly assigned to receive the PCRS (n = 70) reported significantly smaller reductions (i.e., less placebo response) in depression than those who did not receive the PCRS (n = 67). The magnitude of this effect was medium (Cohen's d = 0.40) and was not significantly impacted by diagnostic status. The number of adverse events (i.e., nocebo effect) was also lower in the PCRS group, particularly in the first week of the study. These findings suggest that briefly educating participants about placebo response factors can help mitigate the large placebo response rates that are increasingly seen in failed CNS drug development programs.

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.

Overlapping Molecular Pathways Leading to Autism Spectrum Disorders, Fragile X Syndrome, and Targeted Treatments

Autism spectrum disorders (ASD) are subdivided into idiopathic (unknown) etiology and secondary, based on known etiology. There are hundreds of causes of ASD and most of them are genetic in origin or related to the interplay of genetic etiology and environmental toxicology. Approximately 30 to 50% of the etiologies can be identified when using a combination of available genetic testing. Many of these gene mutations are either core components of the Wnt signaling pathway or their modulators. The full mutation of the fragile X mental retardation 1 (FMR1) gene leads to fragile X syndrome (FXS), the most common cause of monogenic origin of ASD, accounting for ~ 2% of the cases. There is an overlap of molecular mechanisms in those with idiopathic ASD and those with FXS, an interaction between various signaling pathways is suggested during the development of the autistic brain. This review summarizes the cross talk between neurobiological pathways found in ASD and FXS. These signaling pathways are currently under evaluation to target specific treatments in search of the reversal of the molecular abnormalities found in both idiopathic ASD and FXS.

Why we need more research into the placebo response in psychiatry

Placebos are not inert, but exert measurable biological effects. The placebo response in psychiatric illness is important and clinically relevant, but remains poorly understood. In this paper, we review current knowledge about the placebo response in psychiatric medicine and identify research directions for the future. We argue that more research is needed into the placebo response in psychiatric medicine for three broad reasons. First, awareness of factors that cause placebo response, for whom, and when, within clinical trials will allow us to better evidence efficacy of new treatments. Second, by understanding how placebo mechanisms operate in the clinic, we can take advantage of these to optimise the effects of current treatments. Finally, exploring the biological mechanisms of placebo effects might reveal tractable targets for novel treatment development.

The relation between the placebo response, observed treatment effect, and failure to meet primary endpoint: A systematic review of clinical trials of preventative pharmacological migraine treatments

OBJECTIVE

To evaluate the association between the degree of response to placebo in migraine studies and the observed difference between drug and placebo across studies of preventative treatments for migraine.

METHODS

A systematic review was performed using MEDLINE and the Cochrane Central Register of Controlled Clinical Trials from January 1988 to June 2019. Randomized, double-blind, parallel-group, placebo-controlled trials on oral or injection preventative treatments for migraine were included. Single- and multi-variable linear regression analyses were performed on the placebo-subtracted response rate (i.e. placebo responders subtracted from active responders), and the proportion of placebo responders. Fisher's exact tests were performed on the level of placebo response and the success in meeting the study's primary endpoint.

RESULTS

After adjusting for route of administration and number of randomized subjects, there was a statistically significant association between the proportion of patients who were placebo responders and the placebo-subtracted response rate (b = -0.27, p = 0.02). There was a statistically significant difference in trial success rate (60%) between studies with ≤20% placebo responders and studies with > 30% placebo responders (p = 0.03).

CONCLUSION

Considering the detrimental impact that high placebo response can have on clinical trials, it is imperative to find effective solutions to decrease the placebo response and increase assay sensitivity.

Optimizing Aggregated N-Of-1 Trial Designs for Predictive Biomarker Validation: Statistical Methods and Theoretical Findings

Background and Significance: Parallel-group randomized controlled trials (PG-RCTs) are the gold standard for detecting differences in mean improvement across treatment conditions. However, PG-RCTs provide limited information about individuals, making them poorly optimized for quantifying the relationship of a biomarker measured at baseline with treatment response. In N-of-1 trials, an individual subject moves between treatment conditions to determine their specific response to each treatment. Aggregated N-of-1 trials analyze a cohort of such participants, and can be designed to optimize both statistical power and clinical or logistical constraints, such as allowing all participants to begin with an open-label stabilization phase to facilitate the enrollment of more acutely symptomatic participants. Here, we describe a set of statistical simulation studies comparing the power of four different trial designs to detect a relationship between a predictive biomarker measured at baseline and subjects' specific response to the PTSD pharmacotherapeutic agent prazosin.

Methods: Data was simulated from 4 trial designs: (1) open-label; (2) open-label + blinded discontinuation; (3) traditional crossover; and (4) open label + blinded discontinuation + brief crossover (the N-of-1 design). Designs were matched in length and assessments. The primary outcome, analyzed with a linear mixed effects model, was whether a statistically significant association between biomarker value and response to prazosin was detected with 5% Type I error. Simulations were repeated 1,000 times to determine power and bias, with varied parameters.

Results: Trial designs 2 & 4 had substantially higher power with fewer subjects than open label design. Trial design 4 also had higher power than trial design 2. Trial design 4 had slightly lower power than the traditional crossover design, although power declined much more rapidly as carryover was introduced.

Conclusions: These results suggest that an aggregated N-of-1 trial design beginning with an open label titration phase may provide superior power over open label or open label and blinded discontinuation designs, and similar power to a traditional crossover design, in detecting an association between a predictive biomarker and the clinical response to the PTSD pharmacotherapeutic prazosin. This is achieved while allowing all participants to spend the first 8 weeks of the trial on open-label active treatment.