Placebo Manipulations Reverse Pain Potentiation by Unpleasant Affective Stimuli

Mitigating the Nocebo Effect in Biosimilar Use and Switching: A Systematic Review

BACKGROUND

In the context of biosimilar use and switching, a patient's negative perception of a biosimilar might trigger a nocebo effect, where negative expectations unrelated to its pharmacologic action may lead to worsened symptoms, resulting in less perceived therapeutic benefit or worsened adverse events. Considering the crucial role biosimilars have in reducing health care costs and expanding access to safe biologics globally, it is essential to develop and implement effective strategies to mitigate the possible occurrence of such nocebo effects.

OBJECTIVE

The aim of this systematic literature review was two-fold: (i) to review strategies that have been applied and/or tested for minimising the nocebo effect in clinical practice, within and outside the context of biosimilar switching, and (ii) to propose recommendations on useful mitigation strategies to minimise the occurrence of the nocebo effect in the context of biosimilar switching.

METHODS

Biomedical databases PubMed and Embase were screened up until the end of April 2023 with a search string consisting of the following search terms "nocebo", "biosimilar", "mitigation", "strategy", and "prevention" and related synonyms. The search strategy was supplemented by snowballing of the included studies. The quality of the studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Systematic Reviews and Research Syntheses, the Scale for the Assessment of Narrative Review Articles, and the Mixed Methods Appraisal Tool.

RESULTS

Of the 1617 identified and screened records, 60 met the inclusion criteria. Among these, 10 (17%) were conducted within the context of biosimilar switching, 7 of which specifically tested strategies to mitigate the nocebo effect. Among the remaining 50 studies conducted outside the biosimilar switching context, 46 tested mitigation strategies. Across the included studies, 13 distinct mitigation strategies were identified, which can be employed within the context of biosimilar switching: (i) open non-verbal communication, (ii) positive framing, (iii) empathic communication, (iv) validating communication, (v) shared decision making, (vi) self-affirmation, (vii) education of patients and health care professionals about the nocebo effect, (viii) education of patients and health care professionals about biosimilars, (ix) soft-skills training for health care professionals, (x) personalised information, (xi) supporting information, (xii) multidisciplinary approach, (xiii) organisation of the switch.

CONCLUSION

This review has identified a set of strategies that have been tested to mitigate the nocebo effect, which can be applied by health care professionals in the context of biosimilar switching with the aim of mitigating the occurrence of a nocebo effect. We recommend implementing a combination of mitigation strategies for patients and health care professionals to utilise before, during, and after a switch. It should be noted that given the limited number of studies specifically testing nocebo mitigation strategies within the biosimilar switching context to date, it is not yet possible to draw definite conclusions about the effect size of each mitigation strategy individually or in combination.

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.

Exploring the Impact of Affinity and Unpleasantness on Conditioned Pain Modulation among Healthy Individuals

The variability of the Conditioned Pain Modulation (CPM) effect can be attributed to conditioning stimulus (CS) characteristics, such as intensity, duration, unpleasantness, or affinity. This study investigates the impact of affinity and unpleasantness variables on the CPM effect using two protocols (cold water and ischemia) in the same healthy individuals (n = 54). Additional variables were also examined for their potential influence on the CPM effect. The main results are as follows: (1) a higher level of affinity and a lower level of unpleasantness for the stimuli used resulted in a stronger CPM effect; (2) significant differences were observed in the extreme categories (high and low) of both variables, whereas the 'indifferent' group did not show a clear trend; (3) within-subject analysis demonstrated that affinity for the CS had a clear impact on the CPM effect; (4) no correlations were found between the CPM effect and the additional variables, except for the extraversion variable with the CPM effect of the ischemia protocol, and CS duration variable with CPM effect in the cold water protocol; and (5) only the affinity variable explained the CPM effect in both protocols in the multiple linear regression analysis. The affinity variable was found to influence the CPM effects significantly, indicating its important role in our perception and response to pain.

Predicting placebo analgesia in patients with chronic pain using natural language processing: a preliminary validation study

ABSTRACT

Patients with chronic pain show large placebo effects in clinical trials, and inert pills can lead to clinically meaningful analgesia that can last from days to weeks. Whether the placebo response can be predicted reliably, and how to best predict it, is still unknown. We have shown previously that placebo responders can be identified through the language content of patients because they speak about their life, and their pain, after a placebo treatment. In this study, we examine whether these language properties are present before placebo treatment and are thus predictive of placebo response and whether a placebo prediction model can also dissociate between placebo and drug responders. We report the fine-tuning of a language model built based on a longitudinal treatment study where patients with chronic back pain received a placebo (study 1) and its validation on an independent study where patients received a placebo or drug (study 2). A model built on language features from an exit interview from study 1 was able to predict, a priori, the placebo response of patients in study 2 (area under the curve = 0.71). Furthermore, the model predicted as placebo responders exhibited an average of 30% pain relief from an inert pill, compared with 3% for those predicted as nonresponders. The model was not able to predict who responded to naproxen nor spontaneous recovery in a no-treatment arm, suggesting specificity of the prediction to placebo. Taken together, our initial findings suggest that placebo response is predictable using ecological and quick measures such as language use.

Conditioned Pain Modulation Effectiveness: An Experimental Study Comparing Test Paradigms and Analyzing Potential Predictors in a Healthy Population

Conditioned pain modulation (CPM) is an endogenous pain inhibition phenomenon that can be summarized simply as one type of pain being able to inhibit another, which must be in a remote area in relation to the first pain. We aimed to compare the effectiveness of four CPM test paradigms as well as the association of the CPM effect with potential predictors in 72 healthy volunteers. Pressure pain from an algometer was used as the test stimulus, and pain provoked by cold water or ischemic pressure was used as the conditioning stimulus, applied either sequentially or in parallel. No significant differences were found between the test paradigms, although the cold-parallel test showed the most significant effect size (ηP² = 0.614). No association was found between the CPM effect and sociodemographic variables (age or sex), nor anxiety, depression, catastrophizing, previous history of pain or self-perceived pain tolerance. Nevertheless, a strong association was found between the CPM effect and individual affinity for the stimulus in participants who underwent the cold water test paradigm; this explained around 45% of the total CPM effect when the paradigm (cold water) coincided with personal affinity for the stimulus (“I prefer cold to heat”, “cold is not unpleasant”).