Placebo and Nocebo Effects

Reframing pain: the power of individual and societal factors to enhance pain treatment

The effectiveness of analgesics can be increased if synergistic behavioural, psychological, and pharmacological interventions are provided within a supportive environment.

Why clinical trials in disc regeneration strive to achieve completion: Insights from publication status and funding sources

Background

Chronic discogenic low back pain (LBP) poses a significant global burden, yet effective therapeutic interventions directly targeting the underlying degenerative process remain elusive. After demonstrating promising results in preclinical studies, intradiscal injection of cell-based treatments has been increasingly investigated in the clinical setting. However, most clinical trials failed to reach publication, with the few available reports showing only minor improvements. The aim of this study was to analyze the prospective clinical trials registered on ClinicalTrials.gov investigating cell therapies for LBP, with a specific emphasis on identifying critical obstacles hindering study completion, including trial design and funding sources.

Methods

A systematic search of prospective clinical trials investigating cell-based treatments for chronic LBP due to intervertebral disc degeneration was performed on ClinicalTrials.gov. Extracted data encompassed study design, recruitment, experimental treatment modalities, investigated outcomes, current status, completion date, publication status, and funding sources. Fisher's exact test assessed associations between categorical variables, while a multiple logistic regression model aimed to identify factors potentially linked to the publication status of the studies.

Results

Our search identified 26 clinical trials. Among these, only 7 (26.9%) were published, and none of the other studies marked as completed reported any results on ClinicalTrials.gov. Fifty percent of included trials were funded by universities, whereas the rest was sponsored by industry (38.5%) or private institutions (11.5%). Experimental treatments primarily involved cell-based or cell-derived products of varying sources and concentrations. Products containing carriers, such as hyaluronic acid or fibrin, were more frequently funded by industry and private organizations (p = 0.0112). No significant differences emerged when comparing published and nonpublished studies based on funding, as well as between publication status and other variables.

Conclusion

Most clinical trials exploring cell-based disc regenerative therapies for chronic LBP have never reached completion, with only a small fraction reporting preliminary data in publications.

Clinical improvements due to specific effects and placebo effects in conservative interventions and changes observed with no treatment in randomized controlled trials of patients with chronic nonspecific low back pain: a systematic review and meta-analysis

ABSTRACT

Little is known about the contribution of placebo effects and changes observed with no treatment in interventions for nonspecific low back pain (NSLBP). This systematic review assessed the proportions of the overall treatment effect that may be attributable to specific treatment effects, placebo effects, and changes observed with no treatment in randomized controlled trials (RCTs) in patients with NSLBP. Trials published before 2019 were identified from a published systematic review, and the search was updated in MEDLINE, Embase, and Cochrane Central for trials published between January 2019 and March 2023. Three-arm RCTs comparing the effects of experimental interventions vs placebo control vs no intervention reporting pain intensity, physical function, and/or health-related quality of life (HRQoL) were included. Sixteen RCTs with 1436 adults with chronic NSLBP testing conservative and mainly passive interventions were included. For pain intensity (16 studies), 33%, 18%, and 49% of the overall short-term treatment effect was attributable to specific treatment effects, placebo effects, and changes observed with no treatment, respectively. For physical function (11 studies) and HRQoL (6 studies), these proportions were 34%, 13%, and 53%, and 11%, 41%, and 48%, respectively. These results show that approximately half of the overall treatment effect of conservative and mainly passive interventions for patients with chronic NSLBP is attributable to changes observed with no treatment, rather than specific or placebo effects of treatments. However, the certainty of evidence was very low to low, suggesting that the true effects might be markedly different from the effect sizes underlying these estimates.

Repetitive transcranial magnetic stimulation focusing on patients with neuropathic pain in the upper limb: a randomized sham-controlled parallel trial

This study aimed to evaluate the efficacy and safety of navigation-guided repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex in patients with neuropathic pain in the upper limb. This randomized, blinded, sham-controlled, parallel trial included a rTMS protocol (10-Hz, 2000 pulses/session) consisting of five daily sessions, followed by one session per week for the next seven weeks. Pain intensity, as well as pain-related disability, quality of life, and psychological status, were assessed. For the primary outcome, pain intensity was measured daily using a numerical rating scale as a pain diary. Thirty patients were randomly assigned to the active rTMS or sham-stimulation groups. In the primary outcome, the decrease (least square [LS] mean ± standard error) in the weekly average of a pain diary at week 9 compared to the baseline was 0.84 ± 0.31 in the active rTMS group and 0.58 ± 0.29 in the sham group (LS mean difference, 0.26; 95% confidence interval, - 0.60 to 1.13). There was no significant effect on the interaction between the treatment group and time point. Pain-related disability score improved, but other assessments showed no differences. No serious adverse events were observed. This study did not show significant pain relief; however, active rTMS tended to provide better results than sham. rTMS has the potential to improve pain-related disability in addition to pain relief.Clinical Trial Registration number: jRCTs052190110 (20/02/2020).

Psychometric Assessment of an Item Bank for Adaptive Testing on Patient-Reported Experience of Care Environment for Severe Mental Illness: Validation Study

BACKGROUND

The care environment significantly influences the experiences of patients with severe mental illness and the quality of their care. While a welcoming and stimulating environment enhances patient satisfaction and health outcomes, psychiatric facilities often prioritize staff workflow over patient needs. Addressing these challenges is crucial to improving patient experiences and outcomes in mental health care.

OBJECTIVE

This study is part of the Patient-Reported Experience Measure for Improving Quality of Care in Mental Health (PREMIUM) project and aims to establish an item bank (PREMIUM-CE) and to develop computerized adaptive tests (CATs) to measure the experience of the care environment of adult patients with schizophrenia, bipolar disorder, or major depressive disorder.

METHODS

We performed psychometric analyses including assessments of item response theory (IRT) model assumptions, IRT model fit, differential item functioning (DIF), item bank validity, and CAT simulations.

RESULTS

In this multicenter cross-sectional study, 498 patients were recruited from outpatient and inpatient settings. The final PREMIUM-CE 13-item bank was sufficiently unidimensional (root mean square error of approximation=0.082, 95% CI 0.067-0.097; comparative fit index=0.974; Tucker-Lewis index=0.968) and showed an adequate fit to the IRT model (infit mean square statistic ranging between 0.7 and 1.0). DIF analysis revealed no item biases according to gender, health care settings, diagnosis, or mode of study participation. PREMIUM-CE scores correlated strongly with satisfaction measures (r=0.69-0.78; P<.001) and weakly with quality-of-life measures (r=0.11-0.21; P<.001). CAT simulations showed a strong correlation (r=0.98) between CAT scores and those of the full item bank, and around 79.5% (396/498) of the participants obtained a reliable score with the administration of an average of 7 items.

CONCLUSIONS

The PREMIUM-CE item bank and its CAT version have shown excellent psychometric properties, making them reliable measures for evaluating the patient experience of the care environment among adults with severe mental illness in both outpatient and inpatient settings. These measures are a valuable addition to the existing landscape of patient experience assessment, capturing what truly matters to patients and enhancing the understanding of their care experiences.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02491866; https://clinicaltrials.gov/study/NCT02491866.

Reappraising the psychosomatic approach in the study of "chronic orofacial pain": looking for the essential nature of these intractable conditions

As burning mouth syndrome (BMS) and atypical odontalgia (AO) continue to remain complex in terms of pathophysiology and lack explicit treatment protocol, clinicians are left searching for appropriate solutions. Oversimplification solves nothing about what bothers us in clinical situations with BMS or AO. It is important to treat a complicated phenomenon as complex. We should keep careful observations and fact-finding based on a pragmatic approach toward drug selection and prescription with regular follow-up. We also need to assess the long-term prognosis of treatment with a meticulous selection of sample size and characteristics. Further investigation of BMS and AO from a psychosomatic perspective has the potential to provide new insight into the interface between brain function and "chronic orofacial pain."

Nocebo expectations rather than placebo expectations affect topical pain relief: A randomized clinical trial

Patients' expectations and beliefs regarding the potential benefits and harms of medical interventions may induce placebo and nocebo effects, and affect the response to pain therapies. In a randomized clinical trial, we examined the effect of placebo and nocebo expectations on pain relief and adverse events (AEs) in association with a topical treatment among 65 cancer survivors experiencing chronic musculoskeletal pain. Participants received either a 1% camphor-based topical pain patch or a placebo treatment for 14 days. We measured pain severity with the worst pain item of the Brief Pain Inventory (BPI) at baseline and 14 days and treatment expectations at baseline with validated expectation questionnaires. We found that high vs. low nocebo expectations decreased pain severity improvements by 2.5 points (95% confidence interval [CI] -3.8 to -1.2; p<0.001) on a 0-10 numeric rating scale of the BPI and pain response rate by 42.7% (95% CI 0.2-0.6; p<0.001) at day 14, irrespective of placebo expectation status or treatment arms. Patients with high vs. low nocebo expectations in the true arm reported 22.4% more unwanted AEs. High nocebo expectations were associated with increased AEs by 39.5% (odds ratio: 12.0, 95% CI 1.2, 145.5; p=0.029) and decreased pain response in the true arm vs. placebo. Our study demonstrated that nocebo expectations, rather than placebo expectations, elevate the risk of AEs and compromise the effect of topical pain interventions. The findings raise the possibility that nocebo expectations may worsen somatic symptoms through heightening central pain amplification and should be further investigated.

Postprandial symptoms in disorders of gut-brain interaction and their potential as a treatment target

Postprandial, or meal-related, symptoms, such as abdominal pain, early satiation, fullness or bloating, are often reported by patients with disorders of gut-brain interaction, including functional dyspepsia (FD) or irritable bowel syndrome (IBS). We propose that postprandial symptoms arise via a distinct pathophysiological process. A physiological or psychological insult, for example, acute enteric infection, leads to loss of tolerance to a previously tolerated oral food antigen. This enables interaction of both the microbiota and the food antigen itself with the immune system, causing a localised immunological response, with activation of eosinophils and mast cells, and release of inflammatory mediators, including histamine and cytokines. These have more widespread systemic effects, including triggering nociceptive nerves and altering mood. Dietary interventions, including a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols, elimination of potential food antigens or gluten, IgG food sensitivity diets or salicylate restriction may benefit some patients with IBS or FD. This could be because the restriction of these foods or dietary components modulates this pathophysiological process. Similarly, drugs including proton pump inhibitors, histamine-receptor antagonists, mast cell stabilisers or even tricyclic or tetracyclic antidepressants, which have anti-histaminergic actions, all of which are potential treatments for FD and IBS, act on one or more of these mechanisms. It seems unlikely that food antigens driving intestinal immune activation are the entire explanation for postprandial symptoms in FD and IBS. In others, fermentation of intestinal carbohydrates, with gas release altering reflex responses, adverse reactions to food chemicals, central mechanisms or nocebo effects may dominate. However, if the concept that postprandial symptoms arise from food antigens driving an immune response in the gastrointestinal tract in a subset of patients is correct, it is paradigm-shifting, because if the choice of treatment were based on one or more of these therapeutic targets, patient outcomes may be improved.

The importance of context (placebo effects) in conservative interventions for musculoskeletal pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Contextual effects (e.g. patient expectations) may play a role in treatment effectiveness. This study aimed to estimate the magnitude of contextual effects for conservative, non-pharmacological interventions for musculoskeletal pain conditions. A systematic review and meta-analysis of randomized controlled trials (RCTs) that compared placebo conservative non-pharmacological interventions to no treatment for musculoskeletal pain. The outcomes assessed included pain intensity, physical functioning, health-related quality of life, global rating of change, depression, anxiety and sleep at immediate, short-, medium- and/or long-term follow-up.

DATABASES AND DATA TREATMENT

MEDLINE, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL and SPORTDiscus were searched from inception to September 2021. Trial registry searches, backward and forward citation tracking and searches for prior systematic reviews were completed. The Cochrane risk of bias 2 tool was implemented.

RESULTS

The study included 64 RCTs (N = 4314) out of 8898 records. For pain intensity, a mean difference of (MD: -5.32, 95% confidence interval (CI): -7.20, -3.44, N = 57 studies with 74 outcomes, GRADE: very low) was estimated for placebo interventions. A small effect in favour of the placebo interventions for physical function was estimated (SMD: -0.22, 95% CI: -0.35, -0.09; N = 37 with 48 outcomes, GRADE: very low). Similar results were found for a broad range of patient-reported outcomes. Meta-regression analyses did not explain heterogeneity among analyses.

CONCLUSION

The study found that the contextual effect of non-pharmacological conservative interventions for musculoskeletal conditions is likely to be small. However, given the known effect sizes of recommended evidence-based treatments for musculoskeletal conditions, it may still contribute an important component.

SIGNIFICANCE

Contextual effects of non-pharmacological conservative interventions for musculoskeletal conditions are likely to be small for a broad range of patient-reported outcomes (pain intensity, physical function, quality of life, global rating of change and depression). Contextual effects are unlikely, in isolation, to offer much clinical care. But these factors do have relevance in an overall treatment context as they provide almost 30% of the minimally clinically important difference.

When describing harms and benefits to potential trial participants, participant information leaflets are inadequate

BACKGROUND

Providing informed consent for trials requires providing trial participants with comprehensive information about the trial, including information about potential risks and benefits. It is required by the ethical principle of respecting patient autonomy. Our study examines the variation in the way information about potential trial benefits and harms is shared in participant information leaflets (PILs).

METHODS

A total of 214 PILs and informed consent forms from clinical trials units (CTUs) and Clinical Research Facilities (CRFs) in Ireland and the UK were assessed by two authors independently, to check the extent to which they adhered to seven recently developed principles. Discrepancies were resolved by a third.

RESULTS

Usage of the seven principles varied widely between PILs regardless of the intended recipient or trial type. None of the PILs used more than four principles, and some (4%) used none. Twenty-seven per cent of PILs presented information about all known potential harms, whereas 45% presented information on all known potential benefits. Some PILs did not provide any potential harms or potential benefits (8%). There was variation in the information contained in adult and children PILs and across disease areas.

CONCLUSION

Significant variation exists in how potential trial benefits and harms are described to potential trial participants in PILs in our sample. Usage of the seven principles of good practice will promote consistency, ensure informed ethical decision-making and invoke trust and transparency. In the long term, a standardised PIL template is needed.

Evidence and sources of placebo effects in transcranial direct current stimulation during a single session of visuospatial working memory practice

Transcranial direct current stimulation (tDCS) can be used to non-invasively augment cognitive training. However, the benefits of tDCS may be due in part to placebo effects, which have not been well-characterized. The purpose of this study was to determine whether tDCS can have a measurable placebo effect on cognitive training and to identify potential sources of this effect. Eighty-three right-handed adults were randomly assigned to one of three groups: control (no exposure to tDCS), sham tDCS, or active tDCS. The sham and active tDCS groups were double-blinded. Each group performed 20 min of an adapted Corsi Block Tapping Task (CBTT), a visuospatial working memory task. Anodal or sham tDCS was applied during CBTT training in a right parietal-left supraorbital montage. After training, active and sham tDCS groups were surveyed on expectations about tDCS efficacy. Linear mixed effects models showed that the tDCS groups (active and sham combined) improved more on the CBTT with training than the control group, suggesting a placebo effect of tDCS. Participants' tDCS expectations were significantly related to the placebo effect, as was the belief of receiving active stimulation. This placebo effect shows that the benefits of tDCS on cognitive training can occur even in absence of active stimulation. Future tDCS studies should consider how treatment expectations may be a source of the placebo effect in tDCS research, and identify ways to potentially leverage them to maximize treatment benefit.

The Social Epistemology of Clinical Placebos

Many extant theories of placebo focus on their causal structure wherein placebo effects are those that originate from select features of the therapy (e.g., client expectations or "incidental" features like size and shape). Although such accounts can distinguish placebos from standard medical treatments, they cannot distinguish placebos from everyday occurrences, for example, when positive feedback improves our performance on a task. Providing a social-epistemological account of a treatment context can rule out such occurrences, and furthermore reveal a new way to distinguish clinical placebos from standard medical treatments.

Storylines of family medicine VI: ways of being-in the office with patients

Storylines of Family Medicine is a 12-part series of thematically linked mini-essays with accompanying illustrations that explore the many dimensions of family medicine, as interpreted by individual family physicians and medical educators in the USA and elsewhere around the world. In 'VI: ways of being-in the office with patients', authors address the following themes: 'Patient-centred care-cultivating deep listening skills', 'Doctor as witness', 'Words matter', 'Understanding others-metaphor and its use in medicine', 'Communicating with patients-making good use of time', 'The patient-centred medical home-aspirations for the future', 'Routine, ceremony or drama?' and 'The life course'. May readers better appreciate the nuances of patient care through these essays.

Changes in Resting-State Brain Activity After Cognitive Behavioral Therapy for Chronic Pain: A Magnetoencephalography Study

Cognitive behavioral therapy (CBT) is believed to be an effective treatment for chronic pain due to its association with cognitive and emotional factors. Nevertheless, there is a paucity of magnetoencephalography (MEG) investigations elucidating its underlying mechanisms. This study investigated the neurophysiological effects of CBT employing MEG and analytical techniques. We administered resting-state MEG scans to 30 patients with chronic pain and 31 age-matched healthy controls. Patients engaged in a 12-session group CBT program. We conducted pretreatment (T1) and post-treatment (T2) MEG and clinical assessments. MEG data were examined within predefined regions of interest, guided by the authors' and others' prior magnetic resonance imaging studies. Initially, we selected regions displaying significant changes in power spectral density and multiscale entropy between patients at T1 and healthy controls. Then, we examined the changes within these regions after conducting CBT. Furthermore, we applied support vector machine analysis to MEG data to assess the potential for classifying treatment effects. We observed normalization of power in the gamma2 band (61-90 Hz) within the right inferior frontal gyrus (IFG) and multiscale entropy within the right dorsolateral prefrontal cortex (DLPFC) of patients with chronic pain after CBT. Notably, changes in pain intensity before and after CBT positively correlated with the alterations of multiscale entropy. Importantly, responders predicted by the support vector machine classifier had significantly higher treatment improvement rates than nonresponders. These findings underscore the pivotal role of the right IFG and DLPFC in ameliorating pain intensity through CBT. Further accumulation of evidence is essential for future applications. PERSPECTIVE: We conducted MEG scans on 30 patients with chronic pain before and after a CBT program, comparing results with 31 healthy individuals. There were CBT-related changes in the right IFG and DLPFC. These results highlight the importance of specific brain regions in pain reduction through CBT.

Can side effect expectations be assessed implicitly? A comparison of explicit and implicit expectations of vaccination side effects

OBJECTIVE

Treatment expectations alter the probability of experiencing unpleasant side effects from an intervention, including vaccinations. To date, expectations have mostly been assessed explicitly bearing the risk of bias. This study aims to compare implicit expectations of side effects from COVID-19 and flu vaccinations and to examine their relationships with vaccine attitudes and intentions.

METHODS

N = 248 participants took part in a cross-sectional online survey assessing explicit and implicit expectations, as well as vaccine-related attitudes and personal characteristics. A Single Category Implicit Association Test (SC-IAT) was developed to assess implicit side effect expectations. Explicit side effect expectations were measured with the Treatment Expectation Questionnaire (TEX-Q).

RESULTS

Whereas explicit and implicit expectations regarding COVID-19 vaccine were significantly correlated (r = -0.325, p < .001), those correlations could not be found regarding flu vaccine (r = -0.072, p = .32). Explicit measures (COVID-19: β = -0.576, p < .001; flu: β = -0.301, p < .001) predicted the intention to receive further vaccinations more than implicit measures (COVID-19: β = -0.005, p = .93; flu: β = 0.004, p = .96). Explicit measures (COVID-19: OR = 0.360, p < .001; flu: OR = 0.819, p = .03) predicted vaccination status, while implicit measures did not (COVID- 19: OR = 2.643, p = .35; flu: OR = 0.829, p = .61).

CONCLUSION

Expectations to experience side effects from vaccinations can be measured implicitly, in addition to explicit measures. Further investigation needs to determine the relative contribution and additive value of using implicit measures to assess treatment expectations.

Nocebo effects in systemic therapies for adult plaque psoriasis: A systematic review and meta-analysis

Introduction

The nocebo effect is defined as adverse outcomes secondary to negative patient expectations rather than the pharmacologic activity of an intervention. Nocebo effects can reduce treatment adherence and/or persistence. Therefore, nocebo effects in psoriasis need to be defined.

Methods

A Cochrane systematic review was updated with a search of MEDLINE, Embase, and the CENTRAL Register of Controlled Trials for phase II - IV RCTs comparing systemic therapy versus placebo for patients with moderate-to-severe plaque psoriasis. Estimates were pooled using a random effects model, and heterogeneity was evaluated using the I2 statistic. The primary outcome was the pooled proportion of any adverse event (AE) and corresponding risk difference (RD) in patients randomized to placebo versus systemic therapy.

Results

A total of 103 unique trials were identified enrolling 43,189 patients. The overall pooled AE rate in patients randomized to systemic therapy was 57.1% [95% CI: 54.7-59.5%] compared to 49.8% [95% CI: 47.1-52.4%] for placebo [RD 6.7% (95% CI: 4.6-8.9%), p < 0.00001, I2 = 75%]. Both biologic and non-biologic systemic therapy groups had a higher proportion of infectious AEs compared to placebo. No statistically significant RD in serious AEs or AEs leading to discontinuation was identified between systemic therapy and placebo groups.

Discussion

Half of patients exposed to inert placebo in clinical trials of systemic psoriasis therapies experienced AEs, which may be explained by nocebo effects. These findings have important implications when counseling patients and designing future studies.

Placebo and Nocebo Responses in Pharmacological Trials of Tic Disorders: A Meta-Analysis

BACKGROUND

Clinical trials of new drugs for tic disorders (TD) often fail to yield positive results. Placebo and nocebo responses play a vital role in interpreting the outcomes of randomized controlled trials (RCTs), yet these responses in RCTs of TD remain unexplored.

OBJECTIVE

The aim was to assess the magnitude of placebo and nocebo responses in RCTs of pharmacological interventions for TD and identify influencing factors.

METHODS

A systematic search of the Embase, Medline, Cochrane Central Register of Controlled Trials, and PsycINFO databases was conducted. Eligible studies were RCTs that compared active pharmacological agents with placebos. Placebo response was defined as the change from baseline in TD symptom severity in the placebo group, and nocebo response as the proportion experiencing adverse events (AEs) in this group. Subgroup analysis and meta-regression were performed to explore modifying factors.

RESULTS

Twenty-four trials involving 2222 participants were included in this study. A substantial placebo response in TD symptom severity was identified, with a pooled effect size of -0.79 (95% confidence interval [CI] -0.99 to -0.59; I2 = 67%). Forty-four percent (95% CI 27% to 63%; I2 = 92%) of patients experienced AEs while taking inert pills. Sample size, study design, and randomization ratio were correlated with changes in placebo and nocebo responses.

CONCLUSION

There were considerable placebo and nocebo responses in TD clinical trials. These results are of great relevance for the design of future trials and for clinical practice in TD.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration ID CRD42023388397. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Vague sensations. About the background and consequences of discordance between actual and perceived physiological changes

Empirical evidence consistently shows that discordance, also called dissociation or discrepancy, between actual physiological (mainly visceral) events and their perceived counterparts is substantial. On the one hand, we typically do not perceive actual visceral events occurring in our bodies; on the other hand, sometimes we do perceive bodily changes that do not really take place. This narrative review presents the available empirical findings on the discordance, and summarizes possible explanations that approach the phenomenon from the viewpoint of evolution, cognitive development, and predictive processing. Also, the role of top-down factors, such as expectations and experiences is discussed. Finally, practically relevant consequences of the discordance are presented using the examples of mind-body practices, the placebo and nocebo phenomenon, and medically unexplained symptoms. It is concluded that the discordance between actual and perceived body changes can have a negative impact on health, mainly through issues with adherence and other behavioral factors. The existence of actual-perceived discordance should be taught and demonstrated in the elementary and high school, as well as in many areas of higher education.

Clinical Phenotypes Supporting the Relationship Between Sleep Disturbance and Impairment of Placebo Effects

Lack of good sleep or insomnia can lead to many health issues, including an elevated risk of cardiovascular disease, obesity, fatigue, low mood, and pain. While chronic pain negatively impacts sleep quality, the relationship between descending pain modulatory systems like placebo effects and sleep quality is not thoroughly known. We addressed this aspect in a cross-sectional study in participants with chronic pain. Placebo effects were elicited in a laboratory setting using thermal heat stimulations delivered with visual cues using classical conditioning and verbal suggestions. We estimated the levels of insomnia severity with the Insomnia Severity Index and the sleep quality with the Pittsburg Sleep Quality Index. The previous night's sleep continuity was assessed as total sleep time, sleep efficiency, and sleep midpoint the night before the experiment. 277 people with chronic pain and 189 pain-free control individuals participated. Participants with chronic pain and insomnia showed smaller placebo effects than those with chronic pain without insomnia. Similarly, poor sleep quality was associated with reduced placebo effects among participants with chronic pain. Clinical anxiety measured by Depression Anxiety Stress Scales partially mediated these effects. In contrast, placebo effects were not influenced by the presence of insomnia or poor sleep quality in pain-free participants. Sleep continuity the night before the experiment did not influence the placebo effects. Our results indicate that participants who experience insomnia and/or poor sleep quality and chronic pain have smaller placebo effects, and that the previous night sleep continuity does not influence the magnitude of placebo effects. PERSPECTIVE: This study examined the relationship between sleep disturbances and experimentally induced placebo effects. We found that individuals with chronic pain who experience insomnia and poor sleep quality demonstrated reduced placebo effects compared to their counterparts with good sleep quality and no insomnia.

A novel investigation of placebo analgesia through social communication in mice

BACKGROUND AND AIMS

In rodents, placebo analgesia is often investigated through direct conditioning of stimuli, but humans can experience placebo analgesia through expectation without experience. In this study, we sought to determine whether placebo analgesia could be elicited through social communication.

METHODS

Male and female mice were housed in pairs (designated "Active" and "Bystander") and tested for thermal thresholds on a hot plate (53 °C). Food restriction (1 hr/day) was implemented. The Active mouse was taken to a new cage with food dusted with cocoa (COC) or cinnamon (CINN). The Bystander mice were given regular chow in the home cage. After feeding, the Active mice were given morphine (5 mg/kg, SC) or saline and tested on the hot plate. After 5 pairings of a flavor and treatment (counterbalanced), Active mice were tested following access to a flavored food. Bystander mice were given their first direct exposure to a flavored food and tested on the hot plate. The protocol was repeated with naloxone (10 mg/kg, IP) administered prior to testing. Finally, mice were tested in a two-choice test with both flavored foods available.

RESULTS

Active mice showed a conditioned analgesic response to the morphine-paired flavor that was reduced by naloxone. Bystander mice showed a placebo analgesic response to their cagemate's morphine-paired flavor that was not significantly impacted by naloxone. Bystander mice spent more time in the chamber associated with their cagemate's morphine-paired flavor.

CONCLUSIONS

To our knowledge, this is the first investigation of placebo analgesia without direct conditioning, instead relying on social communication between mice. The lack of effect with naloxone pretreatment suggests an opioid-independent effect in the Bystander mice. Placebo analgesia in mice may be possible without direct conditioning to better model the effect of expectation of a novel analgesic in humans.

Expectancy Effects in Psychedelic Trials

Clinical trials of psychedelic compounds like psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltrptamine (DMT) have forced a reconsideration of how nondrug factors, such as participant expectations, are measured and controlled in mental health research. As doses of these profoundly psychoactive substances increase, so does the difficulty in concealing the treatment condition in the classic double-blind, placebo-controlled trial design. As widespread public enthusiasm for the promise of psychedelic therapy grows, so do questions regarding whether and how much trial results are biased by positive expectancy. First, we review the key concepts related to expectancy and its measurement. Then, we review expectancy effects that have been reported in both micro- and macrodose psychedelic trials from the modern era. Finally, we consider expectancy as a discrete physiological process that can be independent of, or even interact with, the drug effect. Expectancy effects can be harnessed to improve treatment outcomes and can also be actively managed in controlled studies to enhance the rigor and generalizability of future psychedelic trials.

Impairment of Hypnosis by Nocebo Response and Related Neurovegetative Changes: A Case Report in Oral Surgery

This article presents the third molar removal in a highly hypnotizable patient, who had been successfully submitted to oral surgery with hypnosis as stand-alone anesthesia in previous sessions. Unexpectedly, hypnosis initially failed, as a result of a nocebo response due to a previous dentist's bad communication; two complaints made by the patient were associated with increased sympathetic activity (as defined by increased heart rate and electrodermal activity and decreased heart rate variability). After deepening of hypnosis, the patient achieved a full hypnotic analgesia allowing for a successful conclusion of the intervention, an event associated with decreased heart rate, electrodermal activity, and increased heart rate variability. Hence, the initial failure was paralleled by a decreased parasympathetic activity and increased sympathetic activity, while hypnotic analgesia was associated with the opposite pattern. The patient's postoperative report indicated that the initial failure of hypnosis depended on a strong nocebo effect because of a previous dentist distrusting hypnosis and persuading her that it was not enough to face a third molar removal.

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.

Nocebo effects and influencing factors in the randomized clinical trials of chronic constipation: A systematic review and meta-analysis

BACKGROUND

Nocebo effects are unavoidable in randomized clinical trials. We aimed to assess the magnitude of nocebo effects and explore the influencing factors in chronic constipation.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases up to July 2022. Randomized, placebo-controlled trials investigating interventions in chronic constipation were included. We conducted a random effects meta-analysis of the proportion of adverse events (AEs) in placebo-treated participants and evaluated the effect of trial characteristics on nocebo effects.

KEY RESULTS

We identified 20,204 studies from the databases, of which 61 were included in the final analysis. The pooled placebo AE rate was 30.41%, and AE-related withdrawal rate was 1.53%. The most commonly reported AEs were headache (5.67%), diarrhea (4.45%), abdominal pain (3.98%), nasopharyngitis (3.39%), nausea (3.36%), and flatulence (2.95%). The placebo AE rate was lower in trials conducted in Asia compared to those in Europe, North America, and international trials. It was also lower in trials diagnosed by Rome III compared to clinician's opinion and Rome II. Additionally, the placebo AE rate was lower in single-center trials compared to multicenter trials, lower in 5-8 weeks therapy compared to 9-12 weeks therapy, lower in participants with FC compared to those with IBS-C and CC, lower in trials with 2 arms compared to 3 arms, and higher in trials with prokinetic drugs compared to secretagogues and laxatives.

CONCLUSIONS & INFERENCES

The placebo AE rate was 30.41% in patients with chronic constipation. Based on our findings, we recommend that researchers take the nocebo effects into consideration when designing and conducting clinical trials and adopt specific measures to mitigate the negative influence of nocebo effects.

Placebo analgesia and nocebo hyperalgesia in patients with Alzheimer disease and healthy participants

ABSTRACT

The role of placebo analgesia and nocebo hyperalgesia in patients with Alzheimer disease (AD) is largely unknown, with only few studies in the area. Therefore, this study aims to investigate to which extent placebo analgesia and nocebo hyperalgesia effects are present in patients experiencing mild-to-moderate AD. Twenty-one patients with AD (test population) and 26 healthy participants (HP; design validation) were exposed to thermal pain stimulation on 3 test days: Lidocaine condition (open/hidden lidocaine administration), capsaicin condition (open/hidden capsaicin administration), and natural history (no treatment), in a randomized, within-subject design. Open lidocaine and open capsaicin were accompanied by verbal suggestions for pain relief and pain increase, respectively. Expected pain and actual pain intensity were measured on a numerical rating scale (0-10). Placebo and nocebo effects were calculated as pain differences in open-hidden lidocaine and capsaicin, respectively, controlled for no treatment. Healthy participants obtained a placebo effect ( P = 0.01) and a trend for a nocebo effect ( P = 0.07). Patients with AD did not obtain a placebo effect ( P = 0.44) nor a significant nocebo effect ( P = 0.86). Healthy participants expected lower and higher pain with open vs hidden lidocaine and capsaicin, respectively ( P < 0.001). The same expectation effects were seen in patients with AD (open vs hidden lidocaine, P = 0.008; open vs hidden capsaicin, P < 0.001). With a well-controlled experimental setting, this study suggests that patients with AD may not experience placebo analgesia effects. Nocebo hyperalgesia effects in patients with AD needs further research. These findings may have implications for the conduction of clinical trials and the treatment of patients with AD in clinical practice.

Efficacy of Home-Based Transcranial Direct Current Stimulation Over the Primary Motor Cortex and Dorsolateral Prefrontal Cortex in the Disability Due to Pain in Fibromyalgia: A Factorial Sham-Randomized Clinical Study

This randomized, double-blind, controlled clinical trial compared the effectiveness of home-based-(HB) active transcranial direct current stimulation (a-tDCS) over the left dorsolateral prefrontal cortex (l-DLPFC) or primary motor cortex (M1) with their respective sham-(s)-tDCS to determine whether a-tDCS would be more effective than s-tDCS in reducing pain and improving disability due to pain. The study included 102 patients with fibromyalgia aged 30 to 65 years old randomly assigned to 1 of 4 tDCS groups using a ratio of 2:1:2:1. The groups included l-DLPFC (a-tDCS, n = 34) and (s-tDCS, n = 17), or tDCS on the M1 (a-tDCS, n = 34) or (s-tDCS, n = 17). Patients self-administered 20 sessions of tDCS, with 2 mA for 20 minutes each day under remote supervision after in-person training. The Mixed Model for Repeated Measurements revealed that a-tDCS on DLPFC significantly reduced pain scores by 36.53% compared to 25.79% in s-tDCS. From baseline to the fourth week of treatment, a-tDCS on M1 reduced pain scores by 45.89% compared to 22.92% over s-tDCS. A generalized linear model showed a significant improvement in the disability scale in the groups that received a-tDCS compared to s-tDCS over M1 20.54% versus 2.49% (χ2 = 11.06, df = 1, P < .001]), while on DLPFC the improvement was 14.29% and 5.77%, with a borderline significance (χ2 = 3.19, df = 1, P = .06]), respectively. A higher reduction in serum brain-derived neurotrophic factor from baseline to treatment end was positively correlated with decreased pain scores regardless of the treatment group. The application of a-tDCS over M1 increased the heat pain threshold and the function of the descending pain inhibitory system. PERSPECTIVE: These findings provide important insights: (1) HB-tDCS has effectively reduced pain scores and improved disability due to fibromyalgia. (2) The study provides evidence that HB-a-tDCS is a viable and effective therapeutic approach. (3) HB-a-tDCS over M1 improved the function of the descending pain inhibitory system and increased the heat pain threshold. Finally, our findings also emphasize that brain-derived neurotrophic factor, as an index of neuroplasticity, may serve as a valuable marker associated with changes in clinical pain measures. TRIAL REGISTRATION: Number NCT03843203.

The Nocebo Effect

Adverse nocebo responses can cause harm to patients and interfere with treatment adherence and effects in both clinic practice and clinical trials. Nocebo responses refer to negative outcomes to active medical treatments in clinical trials or practice that cannot be explained by the treatment's pharmacologic effects. Negative expectancies and nocebo effects are less known than placebo responses. Nocebo effects can be triggered by verbal suggestions, prior negative experiences, observation of others experiencing negative outcomes, and other contextual and environmental factors. As research advances over the years, mechanistic knowledge is accumulating on the neurobiological mechanisms of nocebo effects. This review summarizes studies on different facets of nocebo effects and responses and discusses clinical implications, ethical considerations, and future directions.

Preserving the placebo effect after disclosure: A new perspective on non-deceptive placebos

The present study explores whether a particular style of placebo disclosure could serve as a tool to foster a renewed trust in one's own inherent resources and elicit a meaningful placebo effect. In a motor performance task, two placebo groups received inert transcutaneous electrical nerve stimulation (TENS) in each of four sessions along with information on its force-enhancing properties. Before the final session, one of the placebo groups was informed about the placebo, which was portrayed as a means to unleash an inherent potential. Along with force, we systematically monitored task-specific self-efficacy to test whether this variable would be differentially modulated in the two placebo groups. Compared to two control groups, placebo groups showed higher force and self-efficacy in the last session. No differences in self-efficacy were observed in the placebo groups even after revealing the placebo procedure, suggesting that the disclosure was effective in 'safeguarding' individuals' self-efficacy. These findings may have important implications, paving the way for the use of placebos that not only are ethically permissible but also support individuals' self-efficacy.

A randomized sham-controlled trial of high-dosage accelerated intermittent theta burst rTMS in major depression: study protocol

BACKGROUND

Intermittent theta burst stimulation (iTBS), a novel form of repetitive transcranial magnetic stimulation (rTMS), can be administered in 1/10th of the time of standard rTMS (~ 3 min vs. 37.5 min) yet achieves similar outcomes in depression. The brief nature of the iTBS protocol allows for the administration of multiple iTBS sessions per day, thus reducing the overall course length to days rather than weeks. This study aims to compare the efficacy and tolerability of active versus sham iTBS using an accelerated regimen in patients with treatment-resistant depression (TRD). As a secondary objective, we aim to assess the safety, tolerability, and treatment response to open-label low-frequency right-sided (1 Hz) stimulation using an accelerated regimen in those who do not respond to the initial week of treatment.

METHODS

Over three years, approximately 230 outpatients at the Centre for Addiction and Mental Health and University of British Columbia Hospital, meeting diagnostic criteria for unipolar MDD, will be recruited and randomized to a triple blind sham-controlled trial. Patients will receive five consecutive days of active or sham iTBS, administered eight times daily at 1-hour intervals, with each session delivering 600 pulses of iTBS. Those who have not achieved response by the week four follow-up visit will be offered a second course of treatment, regardless of whether they initially received active or sham stimulation.

DISCUSSION

Broader implementation of conventional iTBS is limited by the logistical demands of the current standard course consisting of 4-6 weeks of daily treatment. If our proposed accelerated iTBS protocol enables patients to achieve remission more rapidly, this would offer major benefits in terms of cost and capacity as well as the time required to achieve clinical response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04255784.

Using hypnotic suggestion in the rehabilitation of working memory capacity after acquired brain injury: study protocol for a randomized controlled trial

OBJECTIVES

Establishment of effective evidence-based interventions in rehabilitation of working memory (WM) deficits after acquired brain injury (ABI) is sorely needed. Despite robust evidence for the efficiency of clinical hypnosis in a wide range of clinical conditions, and improved understanding of mechanisms underlying its effects, the potential of clinical hypnosis in cognitive rehabilitation is underexplored. A recent study has shown large effects of hypnotic suggestion on WM capacity following ABI. This randomized controlled trial aims to evaluate and explore the replicability of these findings and examine the generalization of treatment effects. The study will also explore possible mechanisms of change.

METHODS

Ninety patients will be recruited from the Sunnaas Rehabilitation Hospital. Inclusion criteria are nonprogressive ABI, minimum 12-month post-injury, ongoing WM deficits, and age between 18 and 67 years. Patients will be randomized to either (a) an intervention group receiving four weekly 1-h sessions with induction and hypnosis, (b) an active control group receiving four weekly 1-h sessions of induction and mindfulness, or (c) a passive control group without intervention. The targeted procedure consists of suggestions about enhancing WM functions, for example through the instantiation of preinjury WM capacity in the present using age regression or through visualizations of brain plasticity. The non-targeted suggestions contain no explicit mention of ABI- or WM-related abilities. Each participant will be assessed at baseline, immediately after intervention, and 6 months after baseline. The primary outcome is the WM index from WAIS-IV and self- and informant-reported WM subscale from BRIEF-A, a questionnaire exploring executive functioning in everyday life. Secondary outcomes include a cognitive composite score derived from tests measuring processing speed, executive functions, learning capacity and memory, and self-reported measures of emotional distress, quality of life, and community integration. Exploratory measures include self-rated ABI and WM-related self-efficacy.

DISCUSSION

Rehabilitation of impaired WM after ABI has hitherto yielded limited transfer effects beyond the training material, i.e., improvement effects on everyday WM capacity, and clinical trials of new interventions are thus warranted. Long-standing empirical evidence demonstrates that hypnosis is an effective therapeutic technique in a wide range of conditions, and recent exploratory research has suggested a high efficacy of hypnosis in improving WM capacity in patients with ABI. However, these extraordinary findings need replication in studies applying scientifically rigorous designs. If successful, our ambition is to provide recommendations and materials to implement hypnotic suggestion as an adjunct treatment following ABI. Study findings may inform future studies exploring the use of clinical hypnosis in other areas of rehabilitation, such as mild TBI, and in other neurological conditions where WM deficit is prominent.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05287542. Registered on March 2022 PROTOCOL VERSION: Protocol version 2.0, December 2023.

Outcomes Following Adherence to a Randomized Stroke Trial Protocol

This secondary analysis of a randomized clinical trial assesses whether compliance with the study protocol is associated with a better functional outcome even among participants in the sham-control group.

Pain-sensorimotor interactions: New perspectives and a new model

How pain and sensorimotor behavior interact has been the subject of research and debate for many decades. This article reviews theories bearing on pain-sensorimotor interactions and considers their strengths and limitations in the light of findings from experimental and clinical studies of pain-sensorimotor interactions in the spinal and craniofacial sensorimotor systems. A strength of recent theories is that they have incorporated concepts and features missing from earlier theories to account for the role of the sensory-discriminative, motivational-affective, and cognitive-evaluative dimensions of pain in pain-sensorimotor interactions. Findings acquired since the formulation of these recent theories indicate that additional features need to be considered to provide a more comprehensive conceptualization of pain-sensorimotor interactions. These features include biopsychosocial influences that range from biological factors such as genetics and epigenetics to psychological factors and social factors encompassing environmental and cultural influences. Also needing consideration is a mechanistic framework that includes other biological factors reflecting nociceptive processes and glioplastic and neuroplastic changes in sensorimotor and related brain and spinal cord circuits in acute or chronic pain conditions. The literature reviewed and the limitations of previous theories bearing on pain-sensorimotor interactions have led us to provide new perspectives on these interactions, and this has prompted our development of a new concept, the Theory of Pain-Sensorimotor Interactions (TOPSMI) that we suggest gives a more comprehensive framework to consider the interactions and their complexity. This theory states that pain is associated with plastic changes in the central nervous system (CNS) that lead to an activation pattern of motor units that contributes to the individual's adaptive sensorimotor behavior. This activation pattern takes account of the biological, psychological, and social influences on the musculoskeletal tissues involved in sensorimotor behavior and on the plastic changes and the experience of pain in that individual. The pattern is normally optimized in terms of biomechanical advantage and metabolic cost related to the features of the individual's musculoskeletal tissues and aims to minimize pain and any associated sensorimotor changes, and thereby maintain homeostasis. However, adverse biopsychosocial factors and their interactions may result in plastic CNS changes leading to less optimal, even maladaptive, sensorimotor changes producing motor unit activation patterns associated with the development of further pain. This more comprehensive theory points towards customized treatment strategies, in line with the management approaches to pain proposed in the biopsychosocial model of pain.

Clinical efficacy and nocebo effect following non-medical biosimilar switch in patients with inflammatory bowel disease: A prospective observational study

BACKGROUND

We aimed to evaluate clinical efficacy, biomarker activity, therapeutic drug monitoring (TDM), adverse events (AEs), and nocebo effect in inflammatory bowel disease (IBD) patients who underwent non-medical biosimilar switching.

METHODS

A prospective observational study of consecutive IBD patients who underwent biosimilar switch. Disease activity, biomarkers, TDM, and AEs, including the nocebo effect were captured 8 weeks before switch, at the time of switch (baseline),12 and 24 weeks after the switch.

RESULTS

210 patients were included [81.4% had Crohn's disease (CD), the median age at inclusion: 42 years (IQR 29-61)]. There was no significant difference in the rates of clinical remission at week 8 before switch, baseline, week12, and 24 after switch: 89.0%,93.4%,86.3%,and 90.8%,p = 0.129. The biomarker remission rates were not significantly different; CRP:81.3%,74.7%,81.2%,73.0%,p = 0.343; fecal calprotectin: 78.3%,74.5%,71.7%,76.3%,p = 0.829. The rates of maintaining therapeutic levels (84.7%,83.9%,83.0%,85.3%,p = 0.597) and prevalence of positive anti-drug antibodies remained unchanged. Drug persistence at 12 week of switch was 97.1%, regardless of disease phenotype and originator. The nocebo effect was observed in 13.3%. The discontinuation rate was 4.8%.

CONCLUSION

Despite a significant number of early nocebo complaints within the first 6 months after the biosimilar switch, no significant changes were found in clinical efficacy, biomarkers, therapeutic drug level, or anti-drug antibodies.

Nocebo-associated treatment discontinuation with subcutaneous anti-osteoporotic drugs. A systematic review and meta-analysis of placebo-arm dropouts in randomized-controlled trials

OBJECTIVE

Nocebo is a concept of therapeutics referring to unpleasant symptoms attributed by a patient to a drug, due to negative anticipation. Patients receiving oral anti-osteoporotic drugs in randomized controlled trials (RCT) can experience adverse events leading to dropout, implying that nocebo contributes to treatment discontinuation for these drugs. In this study we aim to investigate the nocebo effect of subcutaneous anti-osteoporotic drugs with a higher compliance rate than orally administered drugs.

STUDY DESIGN

We searched MEDLINE, EMBASE, SCOPUS, and Cochrane databases for double-blind trials investigating subcutaneous anti-osteoporotic drugs for osteoporosis (namely, denosumab, teriparatide, abaloparatide and romosozumab) published up to May 2023.

MAIN OUTCOME MEASURE

Dropouts due to reported adverse events in the placebo arms ("nocebo dropouts").

RESULTS

Data from 17 trials were extracted. Among 10,529 placebo-treated patients the pooled nocebo-dropout percentage was 3 % for denosumab (average: 0.03; 95 % CI: 0.01-0.05), 1 % for romosozumab (average: 0.01; 95 % CI: 0.00-0.03) and 6 % for teriparatide and abaloparatide (average: 0.06; 95 % CI: 0.05-0.07). Nocebo-dropouts were significantly higher in men than women (6 % vs. 3 %, respectively, p = 0.012), in older (mean age >68 years) than in younger patients (5 % vs. 1 %, respectively, p = 0.017) and in those with more severe osteoporosis (based on the percentage of participants with prior fragility-related fractures in the study cohort) compared with patients with no prior fracture history (4 % vs. 1 %, respectively, p = 0.046).

CONCLUSION

Nocebo responses may contribute to treatment discontinuation with subcutaneous anti-osteoporotic drugs in clinical practice. Higher nocebo-related dropout rates in the higher-risk RCT population (older patients, males, those with prior fractures) show that nocebo mechanisms have the potential to hinder therapeutic efforts to specific populations who would benefit most. Prospero registration number CRD42020212843.

Acoustic stimulation for relieving pain during venipuncture: a systematic review and network meta-analysis

OBJECTIVES

To assess whether acoustic stimulations relieve venipuncture pain and determine which stimulation is the most effective type.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

PubMed, Cochrane Central Register of Controlled Trials, Excerpta Medica dataBASE, Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov and the International Clinical Trials Registry Platform databases were systematically searched in September 2023.

STUDY SELECTION

Randomised controlled trials evaluating the efficacy of acoustic stimulations on patients undergoing venipuncture were eligible. Acoustic stimulations were classified into seven categories: five types of acoustic stimulations (music medicine (researcher selected), music medicine (patient selected), music therapy, sounds with linguistic meaning and sounds without linguistic meaning) and two controls (only wearing headphones and no treatment).

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes included self-reported pain intensity assessed during venipuncture and treatment cost, and secondary outcomes were self-reported mental distress and adverse events.

RESULTS

Of 6406 citations, this network meta-analysis included 27 studies including 3416 participants; the mean age was 31.5 years, and 57% were men. Among the five types of acoustic stimulations, only musical interventions, such as music medicine (patient selected) (standardised mean difference (SMD) -0.44 (95% CI: -0.84 to -0.03); low confidence), music medicine (researcher selected) (SMD -0.76 (95% CI: -1.10 to -0.42); low confidence) and music therapy (SMD -0.79 (95% CI: -1.44 to -0.14); low confidence), were associated with improved pain relief during venipuncture compared with no treatment. No significant differences existed between the types of acoustic stimulations. Free-of-charge acoustic stimulations were provided to patients, and no specific adverse events were reported. In many studies, the risk of bias was rated high because of the difficulty of blinding the intervention to the participants and the self-reported pain outcome.

CONCLUSIONS

Music interventions were associated with reduced venipuncture pain. Comparisons between types of acoustic stimulations revealed no significant differences. Therefore, music intervention could be a safe and inexpensive pain relief method for venipuncture.

PROSPERO REGISTRATION NUMBER

CRD42022303852.

A Randomized Placebo-Controlled Trial of the Anti-Nerve Growth Factor Antibody Tanezumab in Subjects With Cancer Pain Due to Bone Metastasis

BACKGROUND

This phase III, randomized, double-blind, placebo-controlled, parallel-group study assessed the efficacy and safety of tanezumab in subjects with cancer pain predominantly due to bone metastasis receiving background opioid therapy.

METHODS

Subjects were randomized (stratified by (1) tumor aggressiveness and (2) presence/absence of concomitant anticancer treatment) to placebo or tanezumab 20 mg. Treatment was administered by subcutaneous injection every 8 weeks for 24 weeks (3 doses) followed by a 24-week safety follow-up period. The primary outcome was change in daily average pain in the index bone metastasis cancer pain site (from 0 = no pain to 10 = worst possible pain) from baseline to week 8.

RESULTS

LS mean (SE) change in pain at week 8 was -1.25 (0.35) for placebo (n = 73) and -2.03 (0.35) for tanezumab 20 mg (n = 72). LS mean (SE) [95% CI] difference from placebo was -0.78 (0.37) [-1.52, -0.04]; P = .0381 with α = 0.0478. The number of subjects with a treatment-emergent adverse event during the treatment period was 50 (68.5%) for placebo and 53 (73.6%) for tanezumab 20 mg. The number of subjects with a prespecified joint safety event was 0 for placebo and 2 (2.8%) for tanezumab 20 mg (pathologic fracture; n = 2).

CONCLUSION

Tanezumab 20 mg met the primary efficacy endpoint at week 8. Conclusions on longer-term efficacy are limited since the study was not designed to evaluate the durability of the effect beyond 8 weeks. Safety findings were consistent with adverse events expected in subjects with cancer pain due to bone metastasis and the known safety profile of tanezumab. Clinicaltrials.gov identifier: NCT02609828.

Eye-mask and earplugs compared with sleep advice leaflet to improve night sleep duration in pregnancy: a randomized controlled trial

STUDY OBJECTIVES

To evaluate at-home use of eye-mask and earplugs (EMEP) versus sleep hygiene advice leaflet (AL) on actigraphy-derived night sleep duration in sleep-deprived pregnant women.

METHODS

A randomized controlled trial was conducted in the antenatal clinic of University Malaya Medical Centre from June 2021 to June 2022. Women at 34-36 weeks gestation with self-reported night sleep duration ≤6 hours were recruited. Participants wore an actigraphy device at night for seven consecutive nights (Observation/Baseline week). Only women whose actigraphy-derived night sleep duration was confirmed to be ≤360 minutes were randomized to use EMEP or AL. Actigraphy was continued for another week (Intervention week). Primary outcome was change in actigraphy-derived night sleep duration from observation to intervention week across trial arms. Secondary outcomes include participants' sleep quality, labor, and neonatal outcome. Comparisons were by Student t-test, Mann-Whitney U test, and chi-square test.

RESULTS

A total of 210 women were randomized: 105 each to EMEP and AL. The increase in night sleep duration over baseline was significantly longer with both EMEP (mean ± SD) 23 ± 41 minutes, p < .001, and AL 10 ± 35 minutes, p = .007. Night sleep duration was longer by 12.9 (95% CI = 2.2 to 23.7) minutes, p = .019 with EMEP over AL. Sleep quality (Global Pittsburgh Sleep Quality Index score) was significantly improved with EMEP (mean ± SD) -2.0 ± 2.5, p < .001, but not with AL -0.3 ± 2.2, p = .246. Labor and neonatal outcomes were not significantly different.

CONCLUSION

EMEP significantly lengthened night sleep duration in sleep-deprived women in late pregnancy and is superior to AL.

CLINICAL TRIAL INFORMATION

"Use of eye masks and earplugs compared with standard advice to improve sleep in pregnancy". https://doi.org/10.1186/ISRCTN19061849. Registered with ISRCTN on 07 May 2021, trial identification number: ISRCTN19061849.

[Exposures to fruit plants in Germany from 2010-2019 : Analysis of the Erfurt joint poison information center database]

BACKGROUND

Inquiries about fruit plants are a frequent reason for consultation with poison information centers, although it should be emphasized that there are no large systematic studies on toxicity based on exposure data. The aim of this work is to determine the risk of poisoning by fruit plants in Germany.

METHODS

Retrospective study of data from the Erfurt Joint Poison Information Center on poisoning inquiries regarding fruit plants (2010-2019) with a detailed presentation of interim results, a tabular handout, plant photos as identification aids, and trend analyses.

RESULTS

From 16,088 plant exposures with 16,700 plants, 214 different fruit plant species were identified. Forty-five fruit plant species (21%) turned out to be relevant (≥ 30 inquiries) and of these, 6 (2.8%) turned out to be highly relevant (≥ 300 inquiries). All relevant plants were assigned a defined risk category (RC): RC 0 (2; 4.4%), RC 1 (26; 57.8%), RC 2 (12; 26.7%), and RC 3 (5; 11.1%). Regarding the inquiries, 6% (459/7607) were related to RC 0; 47.9% (3645/7607) to RC 1; 39.3% to RC 2 (2986/7607); and 6.8% (517/7607) to RC 3. Of the inquiries, 69.5% (5284/7607) were related to young children (1 to < 6 years). Exposure outcomes for all age groups were asymptomatic in 82%, mild in 14.7%, moderate in 3%, and severe in 0.3%, with severe poisoning caused by seven plant species. Interventions were initiated in 66.8% (5079) of the inquiries. Inquiries were most frequently related to Taxus baccata, Ligustrum vulgare, Physalis alkekengi, Prunus laurocerasus, Convallaria majalis, Mahonia spec., Sambucus spec., Lonicera spec., Sorbus aucuparia, Thuja spec., Hedera helix, and Cotoneaster spec.

DISCUSSION

Poisoning by fruit plants in Germany is rare. However, there is a great need for information and education.

"On Suggestion" by John Bostock, 1923: A comparison with twenty-first century understandings of the placebo effect

OBJECTIVES

This paper describes Australian psychiatrist John Bostock's 1923 concept of suggestion and compares it to our understandings, in 2023, of the placebo effect.

CONCLUSIONS

Bostock's 1923 article on "suggestion" gives us a glimpse of the history of Australian psychiatry. It also stimulates thought about the current understandings of the placebo effect. Now, as then, placebo effects can play a critical role in patient outcomes. However, careful consideration is required to ensure contemporary ethical standards are met and harm is not done.

Differential Placebo Responses for Pharmacotherapy and Neurostimulation in Late-Life Depression

BACKGROUND

The magnitude of the placebo response depends on both the modality used as the "placebo" and the intervention with which it is compared, both of which can complicate the interpretation of randomized controlled trials (RCTs) for depression in late life. Given that neurostimulation and pharmacotherapy are among the most common interventions studied for late-life depression, comparing the relative placebo responses in studies of these interventions can aid interpretation of relative effect sizes.

MATERIALS AND METHODS

We analyzed data from two RCTs of adults aged ≥60 years in an episode of treatment-resistant major depression, one comparing aripiprazole and matching placebo pills and the other comparing deep repetitive transcranial magnetic stimulation (rTMS) and sham rTMS. In both RCTs, depression was assessed using the 17-item Hamilton Depression Rating Scale (HDRS-17). The primary comparison occurred after four weeks using analysis of covariance (ANCOVA) of HDRS-17 scores in participants who received placebo pills or sham rTMS. Relevant covariates included years of education, duration of depressive episode, and baseline HDRS-17 score.

RESULTS

Accounting for covariates, there was a larger reduction of HDRS-17 after four weeks in the sham rTMS group (estimated marginal mean ± SE: -5.90 ± 1.45; 95% CI: [-8.82, 2.98]) than in the placebo pills group (-1.07 ± 1.45; [-3.98, 1.85]). There were no significant differences between these groups in the binary outcome analysis of response and remission rates at four weeks or any outcome at trial end point comparison.

CONCLUSIONS

Sham rTMS may have a larger placebo response than placebo pills early in the treatment of older adults with treatment-resistant depression. Differential placebo responses should be considered in both the interpretation and design of RCTs.

Enhancing patient experience assessment with psychological care in severe mental disorders: A study of the PREMIUM program

Incorporating the experiences of patients with severe mental disorders (SMD) into clinical practice offers valuable insights for optimizing psychological care's effectiveness with more patient-centered and personalized interventions. The study aimed to develop a patient-reported experience measure regarding psychological care (PREMIUM-PSY) using adaptive testing and investigate its association with quality of life. In a multicenter study involving 443 patients with SMD, PREMIUM-PSY demonstrated both validity and efficiency (6-item average). Positive patient experiences were associated with enhanced mental and physical quality of life (β = 3.15[2.17;4.12], p < 0.001 and β = 1.18[0.04;2.32], p = 0.042), suggesting PREMIUM-PSY's potential for optimizing psychological care outcomes.

The effect of psychological factors on pain outcomes: lessons learned for the next generation of research

Big data and machine learning techniques offer opportunities to investigate the effects of psychological factors on pain outcomes. Nevertheless, these advances can only deliver when the quality of the data is high and the underpinning causal assumptions are considered. We argue that there is room for improvement and identify some challenges in the evidence base concerning the effect of psychological factors on the development and maintenance of chronic pain. As a starting point, 3 basic tenets of causality are taken: (1) cause and effect differ from each other, (2) the cause precedes the effect within reasonable time, and (3) alternative explanations are ruled out. Building on these tenets, potential problems and some lessons learned are provided that the next generation of research should take into account. In particular, there is a need to be more explicit and transparent about causal assumptions in research. This will lead to better research designs, more appropriate statistical analyses, and constructive discussions and productive tensions that improve our science.

Migraine worsening after COVID-19 and COVID-19 vaccination: Are we facing a nocebo effect?

BACKGROUND AND PURPOSE

In clinical practice patients may report migraine worsening as a consequence of COVID-19 (either infection or vaccines), however, data in this area are lacking. We aimed to investigate the link between COVID-19 and COVID-19 vaccination with migraine worsening and its associated factors.

METHODS

An online survey was sent to migraine patients followed up in a Spanish Headache Clinic, collecting demographic data, and information regarding SARS-CoV-2 infection and vaccination. We asked patients if they had noticed worsening of their migraine after these events and assessed concerns about infection, vaccination and migraine worsening. We also extracted data from participants' own electronic diaries (e-diaries), including 1-month data before and after their reported infection and/or vaccination. We compared participants who self-reported migraine worsening since infection or vaccination with those who did not.

RESULTS

Of 550 participants, 44.9% (247/550) reported having had COVID-19 at least once and 83.3% (458/550) had been vaccinated. Sixty-one patients reported migraine worsening since COVID-19 and 52 since the vaccination. Among the risk factors for perceived migraine worsening in the two settings (infection and vaccination) was concern about migraine worsening itself (infection: odds ratio [OR] 2.498 [95% CI: 1.02-6.273], p = 0.046; vaccination: OR 17.3 [95% CI: confidence interval 5.3-68], p < 0.001). e-diary information was available for 136 of the 550 patients, 38.2% (52/136) for COVID-19 and 39.7% (54/136) for vaccination. We observed no significant difference in headache frequency 1 month before and after infection or vaccination, even when comparing patients with and without self-reported migraine worsening.

CONCLUSIONS

Our preliminary data point to a negligible role of the infection and vaccination on migraine worsening and to the possible presence of a nocebo effect in these settings, as a remarkable proportion of patients had a clear perception of migraine worsening.

Placebo effects on all-cause mortality of patients with COVID-19 in randomized controlled trials of interleukin 6 antagonists: A systematic review and network meta-analysis

AIM

Many randomized controlled trials (RCTs) have investigated the use of interleukin 6 antagonists for the treatment of coronavirus disease 2019 (COVID-19), yielding inconsistent results. This network meta-analysis (NMA) aimed to identify the source of these inconsistent results by reassessing whether participants treated with standard of care (SoC) plus placebo have different all-cause mortality from those treated with SoC alone and to reevaluate the efficacy of interleukin 6 antagonists in the treatment of COVID-19.

METHODS

We conducted a systematic search for relevant RCTs from the inception of electronic databases through 1 September 2022. The primary outcome was all-cause mortality. The secondary outcomes were the incidences of major medical events, secondary infections, all-cause discontinuation, and serious adverse events.

RESULTS

The results of NMA of 33 RCTs showed that patients with COVID-19 treated with SoC plus placebo had lower odds of all-cause mortality than those who received SoC alone (OR, 0.75 [95% confidence interval, 0.58-0.97]). This finding remained consistent after excluding studies with no incident deaths. In addition, when we consider the impact of the widely promoted COVID-19 vaccination and newly developed antiviral treatment strategy, the results from the analysis of the RCT published in 2021 and 2022 remained similar.

CONCLUSION

These findings suggest the potential influence of placebo effects on the treatment outcomes of COVID-19 in RCTs. When evaluating the efficacy of treatment strategies for COVID-19, it is crucial to consider the use of placebo in the design of clinical trials.

Medical Extended Reality Trials: Building Robust Comparators, Controls, and Sham

The explosive pace of development and research in medical extended reality (MXR) is a testament to its promise for health care and medicine. In comparison with this growth, there is a relative sparsity of rigorous clinical trials that establish the efficacy and effectiveness of these interventions. Explicating mechanisms of action across clinical areas and MXR applications is another major area of need. A primary impediment to these goals is a lack of frameworks for trial design, more specifically, the selection of appropriate controls that effectively address unique elements of MXR. This paper delineates a framework for designing controls, sham conditions, and comparators, as well as proposed considerations for MXR trial designs. Special consideration is given to the design of sham conditions. Improved designs would enable more robust findings and the development of generalizable knowledge that could be adopted across MXR interventions.