Nocebo and pain: An overview of the psychoneurobiological mechanisms

Treatment Expectations-You Get What You Expect-and Depression Plays a Role

Positive treatment expectations demonstrably shape treatment outcomes regarding pain and disability in patients with chronic low back pain. However, knowledge about positive and negative treatment expectations as putative predictors of interindividual variability in treatment outcomes is sparse, and the role of other psychological variables of interest, especially of depression as a known predictor of long-term disability, is lacking. We present results of the first prospective study considering expectations in concert with depression in a sample of 200 patients with chronic low back pain undergoing an inpatient interdisciplinary multimodal pain therapy. We analyzed the characteristics of pain and disability, treatment expectation, and depression assessed at the beginning (T0), at the end of (T1), and at 3-month follow-up (T2) of interdisciplinary multimodal pain therapy. Treatment expectations did emerge as a significant predictor of changes in pain intensity and disability, respectively, showing that positive expectations were associated with better treatment outcomes. Mediation analyses revealed a partially mediating effect of treatment expectations on the relation between depression and pain outcomes. PERSPECTIVE: These results expand knowledge regarding the role of treatment expectations in individual treatment outcome trajectories in chronic pain patients, paving the way for much-needed efforts toward optimizing patient expectations and personalized approaches in clinical settings.

The effect of social learning on the nocebo effect: a systematic review and meta-analysis with recommendations for the future

ABSTRACTIndividuals frequently update their beliefs and behaviours based on observation of others' experience. While often adaptive, social learning can contribute to the development of negative health expectations, leading to worsened health outcomes, a phenomenon known as the nocebo effect. This systematic review and meta-analysis examined: whether social learning is sufficient to induce the nocebo effect, how it compares to other forms of induction (classical conditioning and explicit instruction), and factors that influence these effects. The meta-analysis included twenty studies (n = 1388). Social learning showed a medium-large effect size (Hedges' g = .74) relative to no treatment and a to small-medium effect (g = .42) when compared to neutral modelling. The effect of social learning was similar in magnitude to classical conditioning but greater than explicit instruction with a small-medium effect (g = .46). Face-to-face social modelling, longer exposure, higher proportions of female participants and models, and greater observer empathy led to stronger socially-induced nocebo effects. However, further research is essential as only a minority of studies measured important constructs like negative expectancies and state anxiety. Nonetheless, the study highlights social learning as a key pathway for nocebo effects, suggesting it as a target for interventions to reduce the substantial personal and societal burden caused by nocebo effects.

Placebo treatment affects brain systems related to affective and cognitive processes, but not nociceptive pain

Drug treatments for pain often do not outperform placebo, and a better understanding of placebo mechanisms is needed to improve treatment development and clinical practice. In a large-scale fMRI study (N = 392) with pre-registered analyses, we tested whether placebo analgesic treatment modulates nociceptive processes, and whether its effects generalize from conditioned to unconditioned pain modalities. Placebo treatment caused robust analgesia in conditioned thermal pain that generalized to unconditioned mechanical pain. However, placebo did not decrease pain-related fMRI activity in brain measures linked to nociceptive pain, including the Neurologic Pain Signature (NPS) and spinothalamic pathway regions, with strong support for null effects in Bayes Factor analyses. In addition, surprisingly, placebo increased activity in some spinothalamic regions for unconditioned mechanical pain. In contrast, placebo reduced activity in a neuromarker associated with higher-level contributions to pain, the Stimulus Intensity Independent Pain Signature (SIIPS), and affected activity in brain regions related to motivation and value, in both pain modalities. Individual differences in behavioral analgesia were correlated with neural changes in both modalities. Our results indicate that cognitive and affective processes primarily drive placebo analgesia, and show the potential of neuromarkers for separating treatment influences on nociception from influences on evaluative processes.

Statistical learning shapes pain perception and prediction independently of external cues

The placebo and nocebo effects highlight the importance of expectations in modulating pain perception, but in everyday life we don't need an external source of information to form expectations about pain. The brain can learn to predict pain in a more fundamental way, simply by experiencing fluctuating, non-random streams of noxious inputs, and extracting their temporal regularities. This process is called statistical learning. Here, we address a key open question: does statistical learning modulate pain perception? We asked 27 participants to both rate and predict pain intensity levels in sequences of fluctuating heat pain. Using a computational approach, we show that probabilistic expectations and confidence were used to weigh pain perception and prediction. As such, this study goes beyond well-established conditioning paradigms associating non-pain cues with pain outcomes, and shows that statistical learning itself shapes pain experience. This finding opens a new path of research into the brain mechanisms of pain regulation, with relevance to chronic pain where it may be dysfunctional.

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.

Could Relationship-Based Learnt Beliefs and Expectations Contribute to Physiological Vulnerability of Chronic Pain? Making a Case to Consider Attachment in Pain Research

Pain is an interpersonal and inherently social experience. Pain perception and administration of medical treatment all occur in a particular environmental and social context. Early environmental influences and early learning experiences and interactions condition the body's response to different threats (like pain), ultimately shaping the underlying neurophysiology. These early interactions and experiences also determine what situations are perceived as threatening, as well as our belief in our own ability to self-manage, and our belief in others to offer support, during perceived threats. These beliefs intrinsically drive the combination of behaviors that emerge in response to perceived threats, including pain. Such behaviors can be categorized into attachment styles. In this interdisciplinary review, we synthesize and summarize evidence from the neurobiological, psychobiological, psychosocial, and psychobehavioral fields, to describe how these beliefs are embedded in the brain's prediction models to generate a series of expectations/perceptions around the level of safety/threat in different contexts. As such, these beliefs may predict how one experiences and responds to pain, with potentially significant implications for the development and management of chronic pain. Little attention has been directed to the effect of adult attachment style on pain in research studies and in the clinical setting. Using interdisciplinary evidence, we argue why we think this interaction merits further consideration and research. PERSPECTIVE: This review explores the influence of attachment styles on pain perception, suggesting a link between social connections and chronic pain development. It aligns with recent calls to emphasize the social context in pain research and advocates for increased focus on adult attachment styles in research and clinical practice.

Placebo and nocebo effects of percutaneous needle electrolysis and dry-needling: an intra and inter-treatment sessions analysis of a three-arm randomized double-blinded controlled trial in patients with patellar tendinopathy

Objective

This study aimed to investigate the influence of potential placebo and nocebo effects on pain perception of percutaneous needle electrolysis (PNE) in individuals with patellar tendinopathy.

Methods

In this secondary analysis of a three-arm randomized double-blinded controlled trial, intra and inter-session pain perception data from 48 sporting participants with patellar tendinopathy between 18 and 45 years were investigated. Participants were divided into 3 parallel groups: "no-sham group" [PNE intervention], "single-sham group" [sham PNE by using dry needling], and "double-sham group" [sham PNE by using sham needles]. Every group received 4 sessions of the needling therapies targeting the patellar tendon over 8 weeks and was instructed to perform a unilateral eccentric exercise program of the quadriceps muscle on the affected side. Clinical and needle-related pain was assessed before, during, and after each treatment session using a visual analog scale.

Results

No differences were found between groups intra- or inter-session in terms of pain reduction (P = 0.424) despite clinical pain decreased in all groups since the first treatment session (P < 0.001). Furthermore, although the double-sham group showed a lower percentage of participants reporting needle-related pain during needle intervention (P = 0.005), the needle-related pain intensity after needle intervention was similar between groups (P = 0.682). Moreover, there were no group differences for the duration of pain sensation after any needle intervention (P = 0.184), extending in many cases beyond 24 h.

Conclusion

Needling therapies for individuals with patellar tendinopathy are prone to elicit placebo effects regarding clinical pain and nocebo effects regarding needling-related pain. Clinicians and physical therapists treating musculoskeletal pain conditions should consider the added value and potential mechanisms of action before routinely using needle techniques.

Exploratory study of nocebo effect in senior medical students

Background

Νocebo Effect is known to induce adverse symptoms after negative expectations which can be manifested on a physical and psychological level. As 6th year medical students often face a wide range of clinical challenges and may be prone to negative expectations or beliefs affecting their pre-clinical and clinical success, we want to investigate how they are affected by the Nocebo Effect.

Objective

To investigate whether a nocebo effect can be induced when exposing final-year students to the clinical context of their training.

Methods

We used verbal suggestions as a nocebo mechanism and by using three tools, the Illness Attitude Scales, the Symptom Checklist-90, and the State-Trait Anxiety Inventory, we examined the difference in scores on measures of psychometric parameters in 33 participants who were on their 6th year medical and attended three clinics for the first time during their education. The administrations were given before and after attending each clinic, and negative verbal suggestions were given prior to the first administration. We also measured whether the overall number of clinics, had an effect on psychometric parameters.

Results

The results revealed a significant increase in second administration overall in the three clinics in specific psychometric parameters but no statistically significant difference was observed after attending consecutive clinics.

Conclusion

Students reported the occurrence of adverse symptoms in the investigated psychometric parameters, which should be noted in order to avoid potential educational clinical failure.

Translating knowledge on placebo and nocebo effects into clinical practice

Introduction

Positive and negative treatment expectations are powerful modulators of health and treatment outcomes. A substantial part of treatment success is due to contextual factors modulating patient's expectations towards a treatment. Consequently, treatment expectations should be a target of therapeutic interventions themselves.

Objectives

This article highlights the neurobiological underpinnings of treatment expectations as well as strategies to modulate contextual factors to optimize treatment outcomes in daily clinical settings.

Methods

This clinical update aligns with the 2022 IASP Global Year Translating Pain Knowledge into Practice and selectively reviews the best available evidence and practice.

Results

The effects of treatment expectations, also known as placebo and nocebo effects, are observed in various clinical conditions and physiological systems. However, most of our knowledge comes from the field of pain, where expectation effects substantially contribute to overall analgesic treatment outcomes. Experimental placebo analgesia paradigms provide the best illustration of how analgesic effects can be attributed not only to a pharmacological or specific treatment, but instead are the result of the expectation towards the treatment. The impact of expectations on treatment outcome is highly variable between individuals, and the identification of factors predicting an individual's response has proven to be challenging. Further research is required to provide personalized treatment strategies for the daily clinical practice.

Conclusion

Patient's previous experiences and expectations are powerful modulators of treatment efficacy, tolerability, and adherence. By providing a comprehensive overview of recent advances in this field, this review offers valuable insights for clinicians and researchers seeking to improve patient-clinician interaction.

Negative expectations (nocebo phenomenon) in clinical interventions: A scoping review

Unpredictable, undesirable, and confusing reactions in the face of psychological or medical interventions make the clinical presentation more complicated and may represent clinically unexplained symptoms and also disturbed the doctor-patients relationship and decrease patients' benefits of treatment. It seems that negative expectations from the treatment (nocebo phenomenon) can explain such reactions. The aim of the current study is a scoping review and investigate different aspects of the nocebo phenomenon (negative expectations) in clinical interventions. This paper follows a scoping review of the existence, importance, and multidimensions of the nocebo phenomenon in medical and psychological interventions. Data sources include literature databases (ProQuest, PubMed, Google Scholar, and Scopus) reviewed from inception dates to 2023, and the terms negative expectations, nocebo effect, placebo effect, negative placebo, and clinical interventions were searched. The review of the available articles showed that negative expectations play an important role in the process and effectiveness of clinical interventions. Negative expectations (here named nocebo effect) can significantly interfere with rapport and treatment processes. Some underlying components of the nocebo effect include negative expectancies, conditioning, social learning, memory, cognitive distortions, meaning, motivation, somatic focus, negative reinforcements, personality, anxiety, and neurophysiological factors such as CCK, dopamine, and cortisol are proposed for development and presence of nocebo phenomenon in clinical practice. Negative expectations with its biopsychosocial aspects play an important and amazing role in disorganizing medical and psychological interventions. Using appropriate methods to reduce nocebo effects in therapeutic interventions may increase treatment compliance and adherence and increase the effectiveness of interventions.

Landau model for illustrating the learning and unlearning process of nociplastic pain

Recent advancements in understanding the consolidation of nociplastic pain point to a complex, non-conscious learned process of threat perception. Neurobiological pain education is emerging as a promising approach to unlearn nociplastic pain, supported by biopsychosocial tools such as exposure to movement, mindfulness, and group sharing formats. However, this approach is still not well-known among clinicians and the society at large, creating a communication problem that unfortunately perpetuates the suffering of patients. Herein, we propose a Landau model to describe the learning and unlearning process of nociplastic pain, aiming to clarify this complex situation and facilitate communication across different sectors of the society. Nociplastic pain corresponds to a first-order transition, with attention more likely in the alert-protection state than in the trust-explore state. Two appealing results of the model are that the perception of the critical context depends on personal history regarding the symptom and that biopsychosocial loops are formed when there is alarming learned historical information about the symptom, along with confused and contradictory expert information, as seen in nocebo messages. Learning and unlearning in the model correspond to a chang in control parametrs that can weigh more on the alert-protection state, trust-explore state, uncertain state or neutral state. This description clarifies why neurobiological education is the foundational therapy from which others must be built to embody the accessible, clear, and trustworthy information.

The relationship between expectancy, anxiety, and the nocebo effect: a systematic review and meta-analysis with recommendations for future research

Despite the theoretical prominence of expectancy and anxiety as potential mechanisms of the nocebo effect, not all studies measure expectancy and/or anxiety, and there are inconsistent findings among those that do. The present study sought to systematically review and meta-analyse available data to evaluate the relationship between expectancy, anxiety and the nocebo effect. The two key questions were: (1) whether nocebo manipulations influence expectancy and anxiety; and (2) whether expectancy and anxiety are associated with the subsequent nocebo effect. Fifty-nine independent studies (n = 3129) were identified via database searches to 1st August 2021. Nocebo manipulations reliably increased negative expectancy with a large effect (g = .837) and state anxiety with a small effect (g = .312). Changes in expectancy and state anxiety due to the nocebo manipulation were associated with larger nocebo effects (r = .376 and .234, respectively). However, there was no significant association between dispositional anxiety and the nocebo effect. These findings support theories that rely on situationally-induced expectancy and anxiety, but not dispositional anxiety, to explain nocebo effects. Importantly, being malleable, these findings suggest that interventions that target maladaptive negative expectancies and state anxiety could be beneficial for reducing the harm nocebo effects cause across health settings. Recommendations for future research are discussed.

Socially Acquired Nocebo Effects Generalize but Are Not Attenuated by Choice

BACKGROUND

Socially observing a negative treatment-related experience has been shown to modulate our own experience with the same intervention, leading to worsened health outcomes. However, whether this social learning generalizes to similar but distinct interventions has not been explored nor what manipulations can reduce these effects.

PURPOSE

To determine whether socially acquired nocebo effects can be generated by observing a negative experience with a similar, but distinct intervention, and whether choice can reduce these effects.

METHODS

Across three experiments, a community sample of healthy adults (N = 336) either watched a confederate report cybersickness to the same Virtual Reality (VR) activity they were assigned to (Social Modeling: Consistent); a similar, but different VR activity (Social Modeling: Inconsistent); or did not view the confederate (No Social Modeling). Participants were either given choice over the VR (Choice) or assigned by the experimenter (No Choice).

RESULTS

Across the experiments, there was significantly greater cybersickness in both Social Modeling groups relative to No Social Modeling, while the two Social Modeling groups did not differ. There was no significant effect of Choice or a Choice by Social Modeling interaction. Social Modeling elicited greater anxiety and expectancies for cybersickness. Furthermore, these mechanisms mediated the association between social modeling and cybersickness.

CONCLUSIONS

Socially acquired side-effects were demonstrated to generalize to similar, but distinct interventions, highlighting the diffuse and robust effect social modeling can have on our experiences. However, choice did not attenuate the experience of cybersickness, highlighting the need for alternative methods to counteract the effect of social modeling.

A Manifesto in Defense of Pain Complexity: A Critical Review of Essential Insights in Pain Neuroscience

Chronic pain has increasingly become a significant health challenge, not just as a symptomatic manifestation but also as a pathological condition with profound socioeconomic implications. Despite the expansion of medical interventions, the prevalence of chronic pain remains remarkably persistent, prompting a turn towards non-pharmacological treatments, such as therapeutic education, exercise, and cognitive-behavioral therapy. With the advent of cognitive neuroscience, pain is often presented as a primary output derived from the brain, aligning with Engel's Biopsychosocial Model that views disease not solely from a biological perspective but also considering psychological and social factors. This paradigm shift brings forward potential misconceptions and over-simplifications. The current review delves into the intricacies of nociception and pain perception. It questions long-standing beliefs like the cerebral-centric view of pain, the forgotten role of the peripheral nervous system in pain chronification, misconceptions around central sensitization syndromes, the controversy about the existence of a dedicated pain neuromatrix, the consciousness of the pain experience, and the possible oversight of factors beyond the nervous system. In re-evaluating these aspects, the review emphasizes the critical need for understanding the complexity of pain, urging the scientific and clinical community to move beyond reductionist perspectives and consider the multifaceted nature of this phenomenon.

Familiarity From Facial Appearance Leads to Hypoalgesia

Social context has been shown to influence pain perception. This study aimed to broaden this literature by investigating whether relevant social stimuli, such as faces with different levels of intrinsic (based on physical resemblance to known individuals) and episodic (acquired through a previous experience) familiarity, may lead to hypoalgesia. We hypothesized that familiarity, whether intrinsic or acquired through experience, would increase pain threshold and decrease pain intensity. Sixty-seven participants underwent pain induction (the cold pressor test) viewing previously seen faces (Episodic Group) or new faces (Non-episodic Group) that differed in the level of intrinsic familiarity (high vs low). Pain threshold was measured in seconds, while pain intensity was measured on a rating scale of 0 to 10. The results did not show an effect of episodic familiarity. However, compared to low, high intrinsic familiar faces had an attenuating effect on pain intensity, even after controlling for pain expectation. These results suggest that physical features conveying a higher feeling of familiarity induce a top-down hypoalgesic modulation, in line with the idea that familiarity may signal safety and that the presence of familiar others reduce perceived threat-related distress. This study provides further evidence on the social modulation of pain and contributes to the literature on first impressions' influence on social behavior. PERSPECTIVE: Consistent with the idea that familiar others signal safety and reduce the sense of threat, facial features conveying familiarity induce a top-down hypoalgesic modulation. This knowledge may contribute to understanding differences in pain perception in experimental and clinical contexts.

Placebo treatment affects brain systems related to affective and cognitive processes, but not nociceptive pain

Placebo analgesia is a replicable and well-studied phenomenon, yet it remains unclear to what degree it includes modulation of nociceptive processes. Some studies find effects consistent with nociceptive effects, but meta-analyses show that these effects are often small. We analyzed placebo analgesia in a large fMRI study (N = 392), including placebo effects on brain responses to noxious stimuli. Placebo treatment caused robust analgesia in both conditioned thermal and unconditioned mechanical pain. Placebo did not decrease fMRI activity in nociceptive pain regions, including the Neurologic Pain Signature (NPS) and pre-registered spinothalamic pathway regions, with strong support from Bayes Factor analyses. However, placebo treatment affected activity in pre-registered analyses of a second neuromarker, the Stimulus Intensity Independent Pain Signature (SIIPS), and several associated a priori brain regions related to motivation and value, in both thermal and mechanical pain. Individual differences in behavioral analgesia were correlated with neural changes in both thermal and mechanical pain. Our results indicate that processes related to affective and cognitive aspects of pain primarily drive placebo analgesia.

Psychological distress, perceived stress and nocebo effect (multifood adverse reaction) in irritable bowel syndrome patients

BACKGROUND

Psychological distress and perceived stress may complicate the clinical presentation, course, and treatment of patients with functional gastrointestinal disorders. The correlation between psychological distress, perceived stress, and the nocebo effect (multifood adverse reaction) in patients with irritable bowel syndrome (IBS) was the main aim of the present study.

MATERIALS AND METHODS

In this cross-sectional correlation study, data on 4,763 Iranian adults, 748 of whom by purposive sampling were patients with IBS (65.1% female), working in 50 different health centers affiliated to the Isfahan University of Medical Sciences across Isfahan province were examined. For assessing dietary intake, a 106-item self-administered Dish-based Semi-Quantitative Food Frequency Questionnaire that was specifically designed and validated for Iranian adults was used. General Heath Questionnaire 12 and Stressful Life event Questionnaire were used to assess psychological distress and perceived stress. By using a modified Persian version of the Rome III questionnaire, IBS was assessed. Based on researcher-made definition of nocebo effect (multiitem food intolerance), 164 people had the nocebo phenomenon in IBS group.

RESULTS

Age, sex, education, marital status, antidepressant use, and specifically chronic underlying disease (odds ratio [OR]: 3.54, 95% confidence interval [CI]: 1.73-7.23) of general characteristics had a significant correlation (P <.05) with presenting nocebo responses in IBS patients. Psychological distress (OR: 1.415; 95% CI: 0.992-2.020; P = 0.056) had a significant correlation with nocebo effect and did not find significant correlation with perceived stress (OR: 0.999; 95% CI: 0.990-1.008; P = 0.865). Data were analyzed by Chi-square test, analysis of variance, and OR.

CONCLUSION

The present study showed that psychological distress with chronic underlying disease and antidepressant use are important elements in presenting multifood adverse reactions that we named here as the nocebo effect in IBS patients. Reducing psychological distress and managing chronic underlying diseases appear to be an effective factor in reducing the nocebo phenomenon in IBS patients. For managing the nocebo responses in IBS patients, these findings may help clinicians to improve their interventions. Further studies are required to confirm these findings.

Electrophysiological markers for anticipatory processing of nocebo-augmented pain

Nocebo effects on pain are widely thought to be driven by negative expectations. This suggests that anticipatory processing, or some other form of top-down cognitive activity prior to the experience of pain, takes place to form sensory-augmenting expectations. However, little is known about the neural markers of anticipatory processing for nocebo effects. In this event-related potential study on healthy participants (n = 42), we tested whether anticipatory processing for classically conditioned nocebo-augmented pain differed from pain without nocebo augmentation using stimulus preceding negativity (SPN), and Granger Causality (GC). SPN is a slow-wave ERP component thought to measure top-down processing, and GC is a multivariate time series analysis used to measure functional connectivity between brain regions. Fear of pain was assessed with the Fear of Pain Questionnaire-III and tested for correlation with SPN and GC metrics. We found evidence that both anticipatory processing measured with SPN and functional connectivity from frontal to temporoparietal brain regions measured with GC were increased for nocebo pain stimuli relative to control pain stimuli. Other GC node pairs did not yield significant effects, and a lag in the timing of nocebo pain stimuli limited interpretation of the results. No correlations with trait fear of pain measured after the conditioning procedure were detected, indicating that while differences in neural activity could be detected between the anticipation of nocebo and control pain trials, they likely were not related to fear. These results highlight the role that top-down processes play in augmenting sensory perception based on negative expectations before sensation occurs.

A Randomized Controlled Trial Examining the Effect of Topical Refrigerant Spray on the Perception of an Instantaneous Noxious Stimulus

Purpose

Topical refrigerant spray is commonly used with routine hand injections despite mixed evidence about its efficacy in reducing the pain experience. We hypothesize that the use of topical refrigerant spray decreases the pain experience of an instantaneous noxious stimulus.

Methods

Eighty adult volunteer participants were enrolled in the study. We constructed an instrument using the smooth end of a Kirschner wire mounted to the spring of a ballpoint pen to apply an instantaneous noxious stimulus to the long (middle) finger proximal nail fold. Participants completed two trials and were randomized to receive the topical refrigerant spray before either the first or second stimulus and on either the left or right side. Participants were asked to rate the pain of each experience using an 11-point Likert scale and indicate which condition they preferred, if any.

Results

The mean pain ratings for the spray and no-spray conditions were 2.0 and 4.3, respectively, giving a mean difference of -2.3 (P < .001, α = 0.05). Subgroup analysis showed no significant effect of sex or medical versus nonmedical occupation (P = .28 and .11 respectively) on the mean difference in pain rating between the two conditions. Participants who received the spray first had a higher mean difference in pain rating (2.7) than that in those who received it second (1.9). Fifty-nine participants preferred the spray, whereas 21 participants either preferred no spray or had no preference (P < .0001).

Conclusions

The use of topical refrigerant spray significantly decreased the perception of pain from an instantaneous noxious stimulus. A significant majority of participants also preferred the topical refrigerant spray condition. The use of topical refrigerant spray for painful procedures, such as needle insertions, may improve the overall patient experience.

Type of study/level of evidence

Therapeutic I.

Susceptibility to Nocebo Hyperalgesia, Dispositional Optimism, and Trait Anxiety as Predictors of Nocebo Hyperalgesia Reduction

OBJECTIVES

The current paper explores the psychological predictors of nocebo hyperalgesia and whether the reduction of nocebo hyperalgesia can be predicted by susceptibility to nocebo hyperalgesia and psychological characteristics.

METHODS

Nocebo effects on pressure pain were first experimentally induced in 83 healthy female participants through conditioning with open-label instructions about the pain-worsening function of a sham TENS device to assess susceptibility to nocebo hyperalgesia. Participants were then randomized to 1 out of 2 nocebo-reduction conditions (counterconditioning/extinction) or to continued nocebo-conditioning (control), each combined with open-label instructions about the new sham device function. Dispositional optimism, trait and state anxiety, pain catastrophizing, fear of pain, and body vigilance were assessed at baseline.

RESULTS

The results showed that lower optimism and higher trait anxiety were related to a stronger induction of nocebo hyperalgesia. Moreover, a stronger induction of nocebo hyperalgesia and higher trait anxiety predicted a larger nocebo reduction across interventions. Also, nocebo hyperalgesia and optimism moderated the effects of the nocebo-reduction interventions, whereby larger nocebo hyperalgesia and lower optimism were associated with a larger nocebo reduction after counterconditioning, compared with control, and also extinction for larger nocebo hyperalgesia.

DISCUSSION

Our findings suggest that open-label conditioning leads to stronger nocebo hyperalgesia when trait anxiety is high and dispositional optimism is low, while these psychological characteristics, along with larger nocebo hyperalgesia, also predict open-label counterconditioning to be an effective nocebo-reduction strategy. Susceptibility to nocebo hyperalgesia, trait anxiety, and dispositional optimism might be indicators of a flexible pain regulatory system.

Sixty Years After Orne's American Psychologist Article: A Conceptual Framework for Subjective Experiences Elicited by Demand Characteristics

Study participants form beliefs based on cues present in a testing situation (demand characteristics). These beliefs can alter study outcomes (demand effects). Neglecting demand effects can threaten the internal and external validity of studies (including their replication). While demand characteristics garnered much attention following Orne's introduction of this notion, consideration of their effects has become sparse in experimental reports. Moreover, the concept remains confusing. Here, we introduce a conceptual framework for subjective experiences elicited by demand characteristics. The model distinguishes between participants' awareness of the hypothesis, their motivation to comply with it, and the strategy they use to meet situational requirements. We stress that demand characteristics can give rise to genuine experiences. To illustrate, we apply the model to Evaluative Conditioning and the Rubber Hand Illusion. In the General Discussion, we discuss risks and opportunities associated with demand characteristics, and we explain that they remain highly relevant to current research.

The Effects of Expectations and Worries on the Experience of COVID-19 Symptoms

Introduction

The COVID-19 pandemic has been shown to have profound effects on both mental and physical health. Distress and widespread uncertainty about global events and personal risk are associated with increased worry and negative expectations that impact physical health. Thus, the current pandemic poses a possibility for the experience of nocebo effects.

Objective

To evaluate the likelihood of nocebo-induced COVID-19 symptoms in a US sample.

Methods

An online study on the mental health impact of COVID-19 asked participants to complete a set of biweekly surveys over a 6-month period between April 2020 and May 2021. We focus on responses from 3,027 individuals who reported never testing positive for COVID-19. We assessed the association between two types of worry and self-reported symptoms of COVID-19. We used multi-level models to examine variations across and within participants over time. We further investigated the effects of pre-existing health conditions and mental health status.

Results

There was a positive association between symptoms and both general (b= 2.56, p<0.01) and personal worry (b=2.77, p<0.01). However, worry reported at one timepoint was not specifically associated with symptoms reported two weeks later (p = 0.63, p=0.56). We also found that a greater number of prior clinical comorbidities and greater mental health burden were significant predictors of symptom reporting.

Conclusions

These results suggest that increased worries during the COVID-19 pandemic were associated with greater symptoms. Further studies investigating worry and symptoms in populations with confirmed negative COVID-19 tests or isolated populations will be needed to isolate the occurrence of true nocebo effects during the pandemic.

A randomized pharmacological fMRI trial investigating D-cycloserine and brain plasticity mechanisms in learned pain responses

Learning and negative outcome expectations can increase pain sensitivity, a phenomenon known as nocebo hyperalgesia. Here, we examined how a targeted pharmacological manipulation of learning would impact nocebo responses and their brain correlates. Participants received either a placebo (n = 27) or a single 80 mg dose of D-cycloserine (a partial NMDA receptor agonist; n = 23) and underwent fMRI. Behavioral conditioning and negative suggestions were used to induce nocebo responses. Participants underwent pre-conditioning outside the scanner. During scanning, we first delivered baseline pain stimulations, followed by nocebo acquisition and extinction phases. During acquisition, high intensity thermal pain was paired with supposed activation of sham electrical stimuli (nocebo trials), whereas moderate pain was administered with inactive electrical stimulation (control trials). Nocebo hyperalgesia was induced in both groups (p < 0.001). Nocebo magnitudes and brain activations did not show significant differences between D-cycloserine and placebo. In acquisition and extinction, there were significantly increased activations bilaterally in the amygdala, ACC, and insula, during nocebo compared to control trials. Nocebo acquisition trials also showed increased vlPFC activation. Increased opercular activation differentiated nocebo-augmented pain aggravation from baseline pain. These results support the involvement of integrative cognitive-emotional processes in nocebo hyperalgesia.

Young female participants show blunted placebo effects associated with blunted responses to a cue predicting a safe stimulus in the right dorsolateral prefrontal cortex

Discrimination of cues predicting non-nociceptive/nociceptive stimuli is essential for predicting whether a non-painful or painful stimulus will be administered and for eliciting placebo/nocebo (pain reduction/pain enhancement) effects. Dysfunction of the neural system involved in placebo effects has been implicated in the pathology of chronic pain, while female sex is one of the important risk factors for development of chronic pain in young adults. The dorsolateral prefrontal cortex (dl-PFC) is suggested to be involved in placebo effects and is sensitive to sex and age. In this study, to examine the neural mechanisms by which sex and age alter placebo and nocebo effects, we analyzed cerebral hemodynamic activities in the dl-PFC in different sex and age groups during a differential conditioning task. During the training session, two different sounds were followed by low- and high-intensity electrical shocks. In the following recording session, electrical shocks, the intensity of which was mismatched to the sounds, were occasionally administered to elicit placebo and nocebo effects. In young female participants, both placebo effects and hemodynamic responses to the conditioned sounds in the right dl-PFC were significantly lower than those in elderly female participants, while there were no age differences in male participants. The hemodynamic responses to the sound paired with the safe stimulus in the right dl-PFC were significantly correlated with placebo effects, except in the young female group. These results suggest that blunted placebo effects in the young female participants are ascribed to blunted responses to the sound associated with the safe stimulus in the right dl-PFC, and that sex- and age-related factors may alter the responsiveness of the right dl-PFC to associative cues predicting a safe stimulus.

Preventing adverse events of chemotherapy for gastrointestinal cancer by educating patients about the nocebo effect: a randomized-controlled trial

BACKGROUND

Adverse events of chemotherapy may be caused by pharmacodynamics or psychological factors such as negative expectations, which constitute nocebo effects. In a randomized controlled trial, we examined whether educating patients about the nocebo effect is efficacious in reducing the intensity of self-reported adverse events.

METHODS

In this proof-of-concept study, N = 100 outpatients (mean age: 60.2 years, 65% male, 54% UICC tumour stage IV) starting first-line, de novo chemotherapy for gastrointestinal cancers were randomized 1:1 to a nocebo education (n = 49) or an attention control group (n = 51). Our primary outcome was patient-rated intensity of four chemotherapy-specific and three non-specific adverse events (rated on 11-point Likert scales) at 10-days and 12-weeks after the first course of chemotherapy. Secondary outcomes included perceived control of adverse events and tendency to misattribute symptoms.

RESULTS

General linear models indicated that intensity of adverse events differed at 12-weeks after the first course of chemotherapy (mean difference: 4.04, 95% CI [0.72, 7.36], p = .02, d = 0.48), with lower levels in the nocebo education group. This was attributable to less non-specific adverse events (mean difference: 0.39, 95% CI [0.04, 0.73], p = .03, d = 0.44) and a trend towards less specific adverse events in the nocebo education group (mean difference: 0.36, 95% CI [- 0.02, 0.74], p = .07, d = 0.37). We found no difference in adverse events at 10-days follow-up, perceived control of adverse events, or tendency to misattribute non-specific symptoms to the chemotherapy.

CONCLUSIONS

This study provides first proof-of-concept evidence for the efficacy of a brief information session in preventing adverse events of chemotherapy. However, results regarding patient-reported outcomes cannot rule out response biases. Informing patients about the nocebo effect may be an innovative and clinically feasible intervention for reducing the burden of adverse events.

TRIAL REGISTRATION

Retrospectively registered on March 27, 2018 to the German Clinical Trial Register (ID: DRKS00009501).

Nocebo language in anaesthetic patient written information

Recent evidence suggests that how anaesthesia information is presented may influence patient treatment outcomes. We conducted an observational study of anaesthetic-based patient information leaflets across NHS Trusts in England for their nocebo terms vs. therapeutic terms, and how adverse effects were presented. In this study, 'nocebo' is wording that may predispose the patient to expect adverse events such as pain or nausea. Data were extracted and analysed for word frequency, weighted proportion and thematic analysis. In total, 42 patient information leaflets from 61 NHS Trusts were analysed. 'Pain' was the second most common word across the leaflets, median (IQR [range]) 0.82 (0.50-1.0 [0.12-1.47]) per 100 words, second only to 'anaesthesia'. In comparison, 'safe' was the most common positively valanced word which featured eight times less frequently than 'pain' 0.10 (0.07-0.18 [0.0-0.84]) and 'comfort' featured 16.5 times less than 'pain' 0.02 (0.0-0.05 [0.0-0.13]). Multiple examples of phrasing that could have potential nocebo effects included, 'you will need strong painkillers' suggesting 'strong pain' and the need for 'painkillers' rather than using therapeutic terms focusing on 'comfort', 'healing' and 'recovery'. Our results suggest a dominance of phrases with negative content in the presentation of anaesthesia information provided to patients. Clinicians need to be aware of inadvertent generation of nocebo-weighted vs. comfort-weighted communication with patients. Our study findings suggest an opportunity for more emphasis to be placed on therapeutic outcomes and effective mitigation strategies of anaesthesia risks to avoid potential unintended nocebo effects of anaesthesia information leaflets or websites.

Triggers of migraine: where do we stand?

PURPOSE OF REVIEW

In this review, we illustrate and discuss the recent findings regarding the epidemiology and pathophysiology of migraine triggers and their implications in clinical practice.

RECENT FINDINGS

Data from the literature suggest that individual triggers fail to provoke migraine attack in experimental settings. It is therefore possible that more triggers acting in combination are needed to induce an attack by promoting some degree of brain dysfunction and thus increasing the vulnerability to migraine. Caution is however needed, because some of the factors rated as triggers by the patients may actually be a component of the clinical picture of migraine attacks.

SUMMARY

Trigger factors of migraine are endogenous or exogenous elements associated with an increased likelihood of an attack in a short period of time and are reported by up to 75.9% of patients. Triggers must be differentiated from premonitory symptoms that precede the headache phase but do not have a causative role in attack provocation, being rather the very first manifestations of the attack. Identification of real triggers is an important step in the management of migraine. Vice versa, promoting an active avoiding behaviour toward factors whose role as triggers is not certain would be ineffective and even frustrating for patients.

Promoting Acceptance and Adherence to Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial

OBJECTIVE

People with chronic obstructive pulmonary disease (COPD) may suffer from anxiety, depression, low quality of life, and cognitive deficits that could play a role in their clinical conditions. These situations could be worsened during the adaptation process to a new treatment such as noninvasive ventilation (NIV), which is often rejected or inappropriately used. The study aimed to analyze the impact of a brief psychological support intervention on adherence to NIV among patients with COPD.

METHODS

A two-branch randomized controlled trial was conducted on 90 patients with COPD who had an indication for NIV. The experimental group received cognitive behavioral therapy support, including counseling, relaxation, and mindfulness-based exercises. Controls received standard care and watched educational videos. The course had been structured for four to eight meetings at the hospital, at home, and/or via telemedicine.

RESULTS

The psychological intervention was related to improvements in both adherence to NIV (F(304) = 19.054, p < .001) and quality of life (F(156) = 10.264, p = .002) after eight meetings from baseline compared with the control group. Results indicated a significant change in the quality of life also over time (F(71.480) = 8.114, p = .006).

CONCLUSIONS

The findings suggest that the psychological intervention is an appropriate treatment for acceptance of and adherence to NIV in COPD in clinical practice and highlight the importance of determining the underlying reasons for NIV use.Trial Registration:ClinicalTrials.gov identifier NCT02499653.

Unraveling Negative Expectations and Nocebo-Related Effects in Musculoskeletal Pain

This Perspective adapts the ViolEx Model, a framework validated in several clinical conditions, to better understand the role of expectations in the recovery and/or maintenance of musculoskeletal (MSK) pain. Here, particular attention is given to the condition in which dysfunctional expectations are maintained despite no longer being supported by confirmatory evidence (i.e., belief-lifting the arm leads to permanent tendon damage; evidence-after the patient lifts the arm no tendon damage occurs). While the ViolEx Model suggests that cognitive immunization strategies are responsible for the maintenance of dysfunctional expectations, we suggest that such phenomenon can also be understood from a Bayesian Brain perspective, according to which the level of precision of the priors (i.e., expectations) is the determinant factor accounting for the extent of priors' updating (i.e., we merge the two frameworks, suggesting that highly precise prior can lead to cognitive immunization responses). Importantly, this Perspective translates the theory behind these two frameworks into clinical suggestions. Precisely, it is argued that different strategies should be implemented when treating MSK pain patients, depending on the nature of their expectations (i.e., positive or negative and the level of their precision).

[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.

Cross-cultural adaptation of the Revised Neurophysiology of Pain Questionnaire into the Turkish language based on Rasch analysis

BACKGROUND

The Revised Neurophysiology of Pain Questionnaire (Revised-NPQ-Tr) is used to evaluate the chain in pain knowledge. No study has explored its validity and reliability for the Turkish language.

OBJECTIVES

: This study aims to determine the psychometric properties of the Turkish version of the Revised-NPQ-Tr in chronic spinal pain patients.

METHODS

A total of 182 chronic spinal pain patients were included in the study. The Revised-NPQ-Tr results were analyzed using Rasch analysis to measure the psychometric properties.

RESULTS

The Revised-NPQ-Tr indicates misfit to the Rasch model, as evidenced by the borderline significant p value (LR test = 27.626; df = 11; p = .004; Bonferroni-adjusted α = 0.004). Two items were differentially affected by educational status. Removal of poor-functioning items did not improve the psychometric properties of the questionnaire. The Revised-NPQ-Tr is unidimensional and there was no local dependence between items. The questionnaire exhibits known group validity. Test-retest reliability of the questionnaire was moderate [intraclass correlation coefficient (ICC) = 0.629]; however, the internal consistency of the questionnaire was found to be low (Cronbach's α = 0.330; person separation index = 0.373).

CONCLUSION

Although the internal validity of the Revised-NPQ-Tr version was acceptable, its reliability was found to be low. Consequently, the results of Revised-NPQ-Tr should be interpreted carefully in the clinic.

Hypohydration but not Menstrual Phase Influences Pain Perception in Healthy Women

Chronic pain is a pervasive health problem and is associated with tremendous socioeconomic costs. However, current pain treatments are often ineffective due, in part, to the multi-factorial nature of pain. Mild hypohydration was shown to increase experimental pain sensitivity in men, but whether this also occurs in women has not been examined. Fluctuations in ovarian hormones (i.e., 17ß-oestradiol and progesterone) throughout the menstrual cycle may influence a woman's pain sensitivity, as well as hydration levels, suggesting possible interactions between hypohydration and menstrual phase on pain. We investigated the effects of mild hypohydration (HYPO, 24 hr of fluid restriction) on ischaemic pain sensitivity in 14 eumenorrheic women during the early follicular (EF) and mid-luteal (ML) phases of their menstrual cycle. We also examined whether acute water ingestion could reverse the negative effects of hypohydration. Elevated serum osmolality, plasma copeptin, and urine specific gravity indicated mild hypohydration. Compared to euhydration, HYPO reduced pain tolerance (by 34 ± 46 s; P = 0.02, ηp2 = 0.37) and increased ratings of pain intensity (by 0.7 ± 0.7 cm; P = 0.004; ηp2 = 0.55) and unpleasantness (by 0.7 ± 0.9 cm; P = 0.02; ηp2 = 0.40); these results were not influenced by menstrual phase. Water ingestion reduced thirst perception (Visual Analogue Scale, by 2.3 ± 0.9 cm; P < 0.001, ηp2 = 0.88) but did not reduce pain sensitivity. Therefore, hypohydration increases pain sensitivity in women with no influence of menstrual phase.

Association of painful human immunodeficiency virus distal sensory polyneuropathy with aberrant expectation of pain relief: functional magnetic resonance imaging evidence

Mechanisms underlying chronic neuropathic pain associated with HIV-associated distal sensory polyneuropathy are poorly understood, yet 40% of those with distal neuropathy (or 20% of all people with HIV) suffer from this debilitating condition. Central pain processing mechanisms are thought to contribute to the development of HIV neuropathic pain, yet studies investigating central mechanisms for HIV neuropathic pain are few. Considering the motivational nature of pain, we aimed to examine the degree to which expectation of pain onset and expectation of pain offset are altered in sixty-one male patients with HIV-related distal sensory polyneuropathy with (N = 30) and without (N = 31) chronic neuropathic pain. By contrasting painful (foot) and non-painful (hand) sites between those with and without neuropathic pain, we could identify unique neural structures that showed altered activation during expectation of pain offset or relief. Our results showed no evidence for peripheral mechanisms evidenced by lack of significant between group differences in thermo-sensation, subjective pain response or epidermal nerve fibre density. Likewise, we found no significant differences between groups in subjective or brain mechanisms underlying the expectation of pain onset. Conversely, we found significant interaction within right anterior insula during expectation of pain offset in our study in that individuals in the pain group compared to the no-pain group exhibited increased anterior insula activation on the painful compared to the non-painful site. Our findings are consistent with abnormal processing of expectation of pain offset or abnormal pain relief-related mechanisms potentially due to increased emotional distress regarding the experience of chronic endogenous pain.

Pain coping skills training un-locks patient-centered pain care during the COVID- 19 lockdown

BACKGROUND

In 2020, the COVID-19 virus sparked a crisis constituting a nationwide public health emergency that rapidly altered the provision of healthcare services for all Americans. Infectious disease mitigation led to widespread lockdowns of perceived nonessential services, programs, and non-emergent healthcare interventions. This lockdown exacerbated the public health dyad of uncontrolled pain and the opioid epidemic, which was already in a crisis state. Current literature supports the management of uncontrolled pain with a biopsychosocial approach, empowering patients to explore self-care to enhance activities of daily living. Pain Coping Skills Training (PCST) delivers real-life strategies that improve quality of life and strengthen self-efficacy. Self-efficacy has been identified as a patient outcome measure that demonstrates improved patient-perceived function and quality of life despite pain intensity. Studies have shown that nurse practitioners (APRN) are well-positioned to provide PCST to chronic pain sufferers.

METHODS

A pretest-posttest design was utilized for this project to enhance pain self- efficacy through an APRN-led community-based intervention.

INTERVENTION

Community-dwelling adults treated in a specialty pain management practice were self-selected to participate in a 6-week telehealth delivered PCST Program. This APRN delivered program presented basic pain education and a broad range of evidence-based nonpharmacologic pain management self-care tools. The primary outcome was improved Pain Self-efficacy measured with the pain self-efficacy questionnaire (PSEQ), with secondary outcomes of improved perceived pain intensity and function measured with the pain, enjoyment, and general activity (PEG) scale tracked weekly.

RESULTS

Baseline PSEQ and weekly PEG scores were obtained and compared to scores after the program. Collateral data points included confidence in using complementary and alternative nonpharmacologic interventions, satisfaction with the program, and a qualitative patient statement regarding pre-and post-intervention participation.

CONCLUSIONS

This project concluded that a Nurse Practitioner delivered PCST program via telehealth technology could provide community-dwelling adults with an intervention that improves pain self-efficacy, enhances self-reported PEG measures, and meets the social distancing requirements that continue to impact patients during the COVID-19 pandemic.

Pre-Exposure, But Not Overshadowing, Inhibits Nocebo Hyperalgesia

Nocebo hyperalgesia is a pervasive problem that significantly adds to the burden of pain. Conditioning is a key mechanism of nocebo hyperalgesia and recent evidence indicates that, once established, nocebo hyperalgesia is resistant to extinction. This means that preventive strategies are critical. We therefore tested whether two novel strategies - overshadowing (Experiment 1) and pre-exposure (Experiment 2) - could inhibit conditioned nocebo hyperalgesia. Overshadowing involves introducing additional cues during conditioning that should compete with and overshadow learning about the target nocebo cue. Pre-exposure involves pre-exposing the target nocebo cue in the absence of pain, which should diminish its ability to become associated with pain later. In both studies, healthy volunteers (N = 141) received exposure to a series of electrocutaneous pain stimuli with and without a sham electrode 'activated', which they were led to believe was a genuine hyperalgesic treatment. Nocebo conditioning was achieved by pairing sham activation with high pain prior to testing at equivalent pain intensity. In both studies, standard nocebo conditioning led to clear nocebo hyperalgesia relative to natural history controls. In Experiment 1, there was no evidence that overshadowing attenuated nocebo hyperalgesia. Importantly, however, Experiment 2 found that pre-exposure successfully attenuated nocebo hyperalgesia with post hoc analysis suggesting that this effect was dose-dependent. These findings provide novel evidence that pre-exposure, but not overshadowing, could be a cheap and effective way for mitigating the substantial harm caused by conditioned nocebo hyperalgesia in clinical settings. PERSPECTIVE: Nocebo hyperalgesia causes substantial patient burden with few preventive options available. Our study found novel evidence that pre-exposing treatment cues without pain, but not overshadowing them with other cues, has the capacity to inhibit conditioned nocebo hyperalgesia. Pre-exposure may therefore be an effective preventive strategy to combat nocebo hyperalgesia.

Understanding Contextual Factors Effects and Their Implications for Italian Physiotherapists: Findings from a National Cross-Sectional Study

An online cross-sectional survey was conducted using Google Docs software. The aim was to understand the management of contextual factors and to identify which are most relevant and which clinicians underestimate. A total of 1250 physiotherapists were chosen from the database of the Manual Therapists group mailing list (GTM-IFOMPT MO) from July to August 2020. A total of 699 responses were received that were considered valid (56%). Participants (40.83%) identified contextual factors (CFs) as "any element, even involuntary, with which the patient interacts during treatment". Physiotherapists individually chose the representation of CF with the "therapeutic relationship" (82.9%), followed by "therapeutic setting" (75.8%). This choice differed between participants belonging to different age groups. Participants favor communication strategies (76.93%). More than half (57.88%) pay attention to patient involvement during the course of care; and in response to the patients' doubts about the use of treatments with limited scientific efficacy, they suggest different medical treatments. The patient's previous clinical experience is not considered significant and does not influence the choice of treatment. Subsequently, however, the participants reported that they stimulate the patients' positive expectations of the success of the clinical outcome (45.27%). Knowledge of contextual factors in physiotherapy appears limited and very heterogeneous. Future research could increase the focus on professional development.

Effects of ibuprofen administration timing on oral surgery pain: A randomized clinical trial

OBJECTIVE

This study aimed to compare the analgesic effect of ibuprofen 400 mg given 30 min before or immediately after third molars surgery under local anaesthesia.

MATERIALS AND METHODS

The single-centre, randomized, split-mouth, triple-blind, clinical trial involved 38 outpatients, for a total of 76 bilateral symmetrical fully bone impacted mandibular third molars. Each patient was undergone to separate surgical sessions for the right and left side, and ibuprofen was randomly administered 30 min before or immediately after the intervention. Study participants recorded pain intensity using Numerical Rating Scale-11, the timing of rescue therapy intake and overall tablets consumption over 3 days.

RESULTS

The overall pain intensity score was lower in the group receiving ibuprofen immediately after (3.13 ± 2.46) than before (3.58 ± 2.40) surgery, with statistically significant differences only on the second and third days. The mean time to the first using rescue therapy was longer in the postoperative (598.33 ± 422.62 min) than in the preoperative (406.25 ± 149.79 min) analgesic treatment group (p = .123). The number of supplemented ibuprofen tablets did not differ (p = .530) between both groups.

CONCLUSIONS

Within the limits of the present study, ibuprofen administration immediately after surgery seemed to be more effective than preoperative administration.

The contemporary management of neck pain in adults

Neck pain is a common condition with a high prevalence worldwide. Neck pain is associated with significant levels of disability and is widely considered an important public health problem. Neck pain is defined as pain perceived between the superior nuchal line and the spinous process of the first thoracic vertebra. In some types of neck conditions, the pain can be referred to the head, trunk and upper limbs. This article aims to provide an overview of the available evidence on prevalence, costs, diagnosis, prognosis, risk factors, prevention and management of patients with neck pain.

The Unintended Consequences of Adverse Event Information on Medicines' Risks and Label Content

Patients and prescribers need to be aware of adverse drug events to minimize the risk of their occurrence and the severity with which they appear. However, numerous studies show that being informed about adverse events can increase the possibility of suffering from them. Patients tend to overestimate the likelihood of experiencing the adverse events included in the label, and this can contribute to worsening the negative expectations which are at the root of the nocebo effect. In fact, patients can become anxious after reading the undesirable effects section of the leaflet and, in addition to suffering from the nocebo effect, might not take a drug they could benefit from due to the fear of experiencing adverse events. In addition, patients' attention can focus towards non-specific symptoms of daily living that can be misattributed to the drug and included in the labelling. This article proposes a number of suggestions to reduce the abovementioned unintended effects associated with labelling, namely, an increased focus on the excess risk of experiencing adverse events rather than crude incidence, using attribute framing to help patients to better understand the risk of experiencing adverse events, dividing the undesirable effect section of the leaflet into subsections according to the level of evidence supporting causal relationships and, finally, restricting the addition of non-specific adverse events that are also symptoms of daily living to only those where there is enough evidence to show they have been caused by the drug. More studies on how to minimize the nocebo effect induced by adverse event information should be performed, and these should be done in collaboration with health authorities, to reach a shared consensus on how to better present adverse event information in the label.

What Physiotherapists Specialized in Orthopedic Manual Therapy Know About Nocebo-Related Effects and Contextual Factors: Findings From a National Survey

Objective

The aim of this study was to investigate the knowledge of orthopedic manual therapists (OMTs) regarding context factors (CFs) capable of triggering nocebo effects during the treatment and how this knowledge is related to their socio-demographic features.

Design

A cross-sectional online survey.

Setting

National.

Main Outcome Measures

A 20 items questionnaire composed by open-ended and closed single-choice questions was administered to explore: (a) socio-demographic variables (10 questions); (b) the relation between different CFs and nocebo-related effects (2 questions); and (c) the knowledge of participants about nocebo-related effects and how they managed them in the clinical practice (8 questions).

Participants

1288 OMTs were recruited from the database of the Master in Rehabilitation of Musculoskeletal Disorders (MRDM) of the University of Genova from March to May 2019. Inclusion criteria were: (a) to possess a valid email account; (b) to understand and use as a native language the Italian; (c) to be graduated as OMTs; and (d) to be employed as physiotherapists specialized-OMTs during the survey.

Results

791 responses were received (61.4%); 473 of them were male (59.8%), with an average age of 31.0 ± 7.1 years. OMTs defined nocebo-related effects as the psychosocial context effects around therapy and patient with specific biological bases (72.2%). OMTs know that their clinical practice is pervaded by nocebo-related effects (42.5%), triggered by CFs. Participants communicated nocebo-related effects balancing the positive features of the therapy with the negative ones (50.9%), during the decision of the therapeutic plan (42.7%). They reported associative learning as the main mechanism involved in nocebo-related effects (28.8%). OMTs taught and trained patient’s strategies to manage nocebo-related effects (39.6%) through an evaluation and correction of patient’s anxieties, doubts and expectations (37.7%). OMTs most frequently considered themselves to have a “medium” education about nocebo-related effects (48.2%) and that their management should be taught during bachelor (78.6%).

Conclusion

OMTs believed that nocebo-related effects were present in their clinical practice and that they can be triggered by CFs.

Context matters: the psychoneurobiological determinants of placebo, nocebo and context-related effects in physiotherapy

Background

Placebo and nocebo effects embody psychoneurobiological phenomena where behavioural, neurophysiological, perceptive and cognitive changes occur during the therapeutic encounter in the healthcare context. Placebo effects are produced by a positive healthcare context; while nocebo effects are consequences of negative healthcare context. Historically, placebo, nocebo and context-related effects were considered as confounding elements for clinicians and researchers. In the last two decades this attitude started to change, and the understanding of the value of these effects has increased. Despite the growing interest, the knowledge and the awareness of using the healthcare context to trigger placebo and nocebo effects is currently limited and heterogeneous among physiotherapists, reducing their translational value in the physiotherapy field.

Objectives

To introduce the placebo, nocebo and context-related effects by: (1) presenting their psychological models; (2) describing their neurophysiological mechanisms; (3) underlining their impact for the physiotherapy profession; and (4) tracing lines for future researches.

Conclusion

Several psychological mechanisms are involved in placebo, nocebo and context-related effects; including expectation, learning processes (classical conditioning and observational learning), reinforced expectations, mindset and personality traits. The neurophysiological mechanisms mainly include the endogenous opioid, the endocannabinoid and the dopaminergic systems. Neuroimaging studies have identified different brain regions involved such as the dorsolateral prefrontal cortex, the rostral anterior cingulate cortex, the periaqueductal gray and the dorsal horn of spine. From a clinical perspective, the manipulation of the healthcare context with the best evidence-based therapy represents an opportunity to trigger placebo effects and to avoid nocebo effects respecting the ethical code of conduct. From a managerial perspective, stakeholders, organizations and governments should encourage the assessment of the healthcare context aimed to improve the quality of physiotherapy services. From an educational perspective, placebo and nocebo effects are professional topics that should be integrated in the university program of health and medical professions. From a research perspective, the control of placebo, nocebo and context-related effects offers to the scientific community the chance to better measure the impact of physiotherapy on different outcomes and in different conditions through primary studies.

Nocebo hyperalgesia can be induced by classical conditioning without involvement of expectancy

Influential theoretical accounts take the position that classical conditioning can induce placebo effects through conscious expectancies. In the current study two different conditioning procedures (hidden and open) were used to separate expectancy from conditioning in order to reveal the role of expectancy in the formation of nocebo hyperalgesia. Eighty-seven healthy females were randomly assigned to three groups (hidden conditioning, open conditioning, and control). Participants were selected according to the Fear of Pain Questionnaire scores and assigned to two subgroups: high and low level of fear of pain (trait). They received electrocutaneous pain stimuli preceded by either an orange or blue color. During the conditioning phase, one color was paired with pain stimuli of moderate intensity (control stimuli) and the other color was paired with pain stimuli of high intensity (nocebo stimuli) in both hidden and open conditioning groups. Only participants in the open conditioning group were informed about this association, however just before the testing phase the expectancy of hyperalgesia induced in this way was withdrawn. In the control group, both colors were followed by control pain stimuli. During the testing phase all participants received a series of stimuli of the same intensity, regardless of the preceding color. Participants rated pain intensity, expectancy of pain intensity and fear (state). We found that nocebo hyperalgesia was induced by hidden rather than open conditioning. The hidden conditioning procedure did not produce conscious expectancies related to pain. Nocebo hyperalgesia was induced in participants with low and high fear of pain and there was no difference in the magnitude of the nocebo effect between both groups. Nocebo hyperalgesia was not predicted by the fear of upcoming painful stimuli.

Psychological Therapy for Centralized Pain: An Integrative Assessment and Treatment Model

OBJECTIVE

Chronic pain is a significant health problem that is increasing in prevalence, and advances in treatment are needed.

METHODS

We briefly review the leading evidence-based psychological therapies for chronic pain-cognitive-behavioral and acceptance/mindfulness-based therapies-and examine several limitations and missing perspectives of these approaches. We review six lesser-known interventions that address these limitations, and we describe our integrative model for psychological assessment and treatment of centralized pain. We present a typical patient and describe how we apply this approach, along with challenges to its implementation and possible solutions to these challenges.

RESULTS

Greater pain treatment efficacy may be possible if clinicians: (a) distinguish patients with primarily centralized (i.e., somatoform or nociplastic) pain from those with primarily peripheral (nociceptive, inflammatory, or neuropathic) pain; (b) acknowledge the capacity of the brain not only to modulate pain but also generate as well as attenuate or eliminate centralized pain; (c) consider the powerful role that adverse life experiences and psychological conflicts play in centralized pain; and (d) integrate emotional processing and interpersonal changes into treatment. Our integrative treatment involves delivering a progression of interventions, as needed, to achieve pain reduction: tailored pain neuroscience education, cognitive and mindfulness skills to decrease the pain danger alarm mechanism, behavioral engagement in avoided painful and other feared activities, emotional awareness and expression to reverse emotional avoidance and overcome trauma or psychological conflict, and adaptive communication to decrease interpersonal stress.

CONCLUSIONS

This integrative assessment and treatment model has the potential to substantially reduce and sometimes eliminate centralized pain by changing the cognitive, behavioral, emotional, and interpersonal processes that trigger and maintain centralized pain.

Antidepressant-placebo differences for specific adverse events in major depressive disorder: A systematic review

BACKGROUND

Adverse events (AEs) are known to occur while patients are treated with placebos, part of the so-called nocebo effect. Yet evidence is limited regarding the likelihood that specific AEs occurring with antidepressant treatment are or are not due to nocebo effects.

METHODS

This study identified 56 placebo-controlled, randomized controlled trials (RCTs) of antidepressant monotherapy for adults with major depressive disorder that reported AE rates in sufficient detail for comparison. Poisson regression analyses compared rates of AEs according to antidepressant class weighted by study population to determine which separated from placebo. A "nocebo index" was also calculated (with 0 defined as the lowest rate and 1 or higher indicating the same or greater rate of an AE in the placebo group).

RESULTS

Numerous AEs did not differ statistically between antidepressant classes and placebo including worsening psychiatric symptoms, all forms of pain, weight gain and respiratory symptoms. Nevertheless, a number of AEs were significantly more common in antidepressants than placebos across multiple antidepressant classes. These were predominantly neurological, sexual and anticholinergic effects. Several AEs that separated statistically between antidepressants and placebos nevertheless had moderate nocebo indices (≥0.5). For example, dizziness in SSRIs separated significantly from placebo (OR 1.50, 95%CI 1.13-1.99) but had a nocebo index of 0.67.

LIMITATIONS

This study relied on multiple RCTs with subtle design differences.

CONCLUSIONS

This study identified several AEs that are likely the physiological result of antidepressants and many that likely represent nocebo effects. These results should inform clinical decision making and discussions with patients.

Pain and satisfaction: healthcare providers' facial appearance matters

Trait inferences based solely on facial appearance affect many social decisions. Here we tested whether the effects of such inferences extend to the perception of physical sensations. In an actual clinical setting, we show that healthcare providers' facial appearance is a strong predictor of pain experienced by patients during a medical procedure. The effect was specific to familiarity: facial features of healthcare providers that convey feelings of familiarity were associated with a decrease in patients' perception of pain. In addition, caring appearance of the healthcare providers was significantly related to patients' satisfaction with the care they received. Besides indicating that rapid, unreflective trait inferences from facial appearance may affect important healthcare outcomes, these findings contribute to the understanding of the mechanisms underlying social modulation of pain perception.

Advancing the understanding of placebo effects in psychological outcomes of exercise: Lessons learned and future directions

Despite the apparent strength of scientific evidence suggesting that psychological benefits result from both acute and chronic exercise, concerns remain regarding the extent to which these benefits are explained by placebo effects. Addressing these concerns is methodologically and at times conceptually challenging. However, developments in the conceptualisation and study of placebo effects from the fields of psychology, neuroscience, pharmacology, and human performance offer guidance for advancing the understanding of placebo effects in psychological responses to exercise. In clinical trials, expectations can be measured and experimentally manipulated to better understand the influence of placebo effects on treatment responses. Further, compelling evidence has shown that the contribution of placebo effects and their underlying neurobiological mechanisms to treatment effects can be measured without administering a traditional placebo (e.g. inert substance) by leveraging psychological factors such as expectations and conditioning. Hence, the purpose of this focused review is to integrate lessons such as these with the current body of literature on placebo effects in psychological responses to exercise and provide recommendations for future research directions.