¿Influye la comunicación con el paciente sobre la kinesiofobia? Una revisión sistemática / Does patient communication influence kinesiophobia? A systematic review

El objetivo de la presente revisión sistemática consistió en determinar el efecto de la comunicación en el ámbito sanitario sobre la kinesiofobia. Para ello, se realizó una búsqueda bibliográfica en siete bases de datos entre noviembre de 2022 y febrero de 2023. La revisión se efectuó acorde a la declaración Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) y para el análisis de la calidad metodológica se utilizaron: la escala Physiotherapy Evidence Database (PEDro), los criterios de Van Tulder y el análisis del riesgo de sesgo de la Colaboración Cochrane. Se incluyeron un total de 13 artículos que presentaron una calidad metodológica media de 7,1 sobre 10. Se obtuvieron resultados significativos para al menos una variable (kinesiofobia, discapacidad o nivel de actividad física) en 12 trabajos. Existe evidencia sólida de que la comunicación puede influir sobre la kinesiofobia del sujeto. Es más probable que esta influencia ocurra en un sentido negativo o discapacitante, pero también puede actuar en sentido positivo disminuyendo la misma. (AU)

The aim of the present systematic review was to determine the effect of communication in the health care setting on kinesiophobia. To this end, a literature search was conducted in seven databases between November 2022 and February 2023. The review was carried out following the PRISMA statement and for the analysis of methodological quality we used: PEDro Scale, Van Tulder criteria and risk of bias analysis of the Cochrane Collaboration. A total of 13 articles were included with a mean methodological quality of 7.1 out of 10. Significant results were obtained for at least one variable (kinesiophobia, disability or level of physical activity) in 12 articles. There is strong evidence that communication can influence a subject's kinesiophobia. This influence is most likely to be in a negative or disabling sense, but it can also act in a positive sense by decreasing it. (AU)

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.

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.

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.

Investigation of treatment continuity, usefulness, and nocebo effect in switching from the original etanercept to its biosimilar in patients with rheumatoid arthritis: A JET observational study in Japanese clinical practice.

OBJECTIVES: To assess the usefulness and onset of nocebo effects after switching from the original etanercept (ETN) to a biosimilar (BS) in routine clinical practice at rheumatology clinics in Japan (13 sites). METHODS: A total of 165 patients (87.0% women, age = 57.88 ± 15.07 years, and disease duration = 10.32 ± 7.71 years), whose low disease activity was maintained with the original ETN for ≥12 weeks, and who agreed to switch treatment to its BS, were included. The end-points were disease activity score 28 (DAS28)-C-reactive protein and DAS28-erythrocyte sedimentation rate. RESULTS: No significant difference was observed between the changes in DAS28-C-reactive protein and DAS28-erythrocyte sedimentation rate >12 weeks before switching and >12 weeks after switching (P = 0.132 and 0.334, respectively). The treatment continuation rate during the 52 weeks after switching to BS was 97.3%. During this period, BS was discontinued in only four patients, and no nocebo effects were suspected in these four patients. CONCLUSION: Switching from ETN to BS was effective even in routine clinical practice at rheumatology clinics in Japan, and no nocebo effects were observed. Sufficient explanations to patients by rheumatologists and the additional payment for drug costs between patients at hospital visits effectively improved the continuation rate without any nocebo effect.

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.

A novel paradigm examining the remote induction of nocebo effects online.

OBJECTIVE: Side effect information is routinely communicated online. However, limited experimental evidence exists regarding the role of this information in generating maladaptive health outcomes (i.e., the nocebo effect). A novel paradigm was developed to remotely induce the nocebo effect via provision of online side effect information. METHOD: Participants were given information regarding the positive effects of low frequency noise (LFN). A proportion were additionally warned of LFN-induced side effects. Study 1 (N = 423) investigated the source of information (listed vs. socially communicated side effects), while Study 2 (N = 560) investigated the role of positive and negative affects on attenuating and exacerbating the nocebo effect. Pooled analysis (N = 983) explored the effect of negative and positive expectations on both the nocebo effect and positive outcomes. RESULTS: Across studies, a significant nocebo effect in the warned side effects occurred after LFN exposure. This did not vary by source of information (Study 1) nor was it attenuated via the induction of positive affect (Study 2). Both studies demonstrated a reduction in positive outcomes among those receiving side effect information. Pooled analysis revealed that negative, but not positive, expectations mediated the nocebo effect. Positive and negative expectations interacted to predict positive outcomes. Holding negative expectations appeared to block positive health outcomes. Specifically, when negative expectations were above average, there was no effect of positive expectations on positive outcomes. CONCLUSIONS: Nocebo effects were remotely generated via minimal provision of side effect information. Pooled analysis revealed that future interventions should target positive and negative expectations to reduce side effects. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Diet, gym, supplements, or maybe it is all in your mind? A systematic review and meta-analysis of studies on placebo and nocebo effects in weight loss in adults.

INTRODUCTION: There is evidence that placebo and nocebo effects are significant for many conditions, but their impact on weight loss has not yet been well described. MATERIAL AND METHODS: A systematic review of studies indexed on PubMed, Cochrane, PsycINFO, PsycARTICLES, TripDatabase, and Embase was carried out. Studies (1) with at least two study groups - placebo and a corresponding control group; (2) published in English; and (3) focusing on adults participating in weight loss programs or on placebo/nocebo effects in weight loss were included. Synthesis and meta-analysis of the results of studies with comparable research plans were performed. RESULTS: Some preliminary trends suggesting placebo and nocebo effects in weight loss were found. Placebo effects manifested in trends towards a slightly greater reduction of Body Mass Index (BMI) and body fat ratio in the placebo compared with the control groups. On the other hand, in one study, it was found that the expectancy effects of taking oral weight-loss agents might be disadvantageous (i.e., because they elicit a nocebo effect on weight loss). CONCLUSION: The findings suggest a possibility that the nocebo effect may occur when an intervention has a medical context. In contrast, the placebo effect can be observed in cases where the intervention is of a different nature. However, considering the low number of studies analyzing the use of placebos in weight loss, new primary research is needed.

Placebo Hypoalgesia and Nocebo Hyperalgesia Induced by Observational Learning May Be Difficult to Disentangle in a Laboratory Setting.

Observational learning (OBL) (seeing pain/pain treatment in others) can evoke placebo hypoalgesia and nocebo hyperalgesia. Data that compare these effects and illuminates the role of expectations and empathy are scarce. Healthy participants (n = 105) were randomized to: 1) placebo OBL, 2) nocebo OBL, or 3) no-observation control group. OBL consisted of a model simulating pain relief or increase after a sham ointment was applied to one arm. Pain was evoked with thermal stimuli on both arms (ointment, contralateral) at baseline and postobservation. Expectations, pain ratings, and physiological data (eg, skin conductance level) were collected. A 3 × 2 × 2 (Group × Arm × Phase) mixed analyses of variance revealed a 3-way interaction that confirmed that OBL modulates pain: F(2, 93) = 6.08, P = .003, ηp2 = .12. Significant baseline-to-post-observation pain increases were shown in the nocebo OBL group, with a bigger increase for the arm with ointment (both P ≤ .007). In the placebo OBL group, pain was higher for the contralateral relative to the ointment arm (P < .001). Baseline-to-post-observation pain increase was significant for the contralateral arm (P < .001). Expectation mediated these effects. Skin conductance level decreased over time during ointment trials in the nocebo OBL group, suggesting reduced physiological arousal. The findings illustrate that OBL modulates pain through expectations. In the placebo OBL group, the pain did not decrease for the ointment but increased for the contralateral stimuli, which may reflect nocebo learning. Experimental OBL paradigms typically examine relative differences between ointment and contralateral cues. This can complicate disentangling placebo hypoalgesia and nocebo hyperalgesia in laboratory settings. Implications for existing theories are discussed. PERSPECTIVE: Data that systematically compare placebo hypoalgesia and nocebo hyperalgesia induced by OBL are scarce. The current work illustrates that these effects may be more difficult to disentangle than previously assumed, which could have implications for existing theories on OBL and placebo effects and their translation to clinical practice.

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.

Placebo and nocebo responses in painful diabetic neuropathy: systematic review and meta-analysis.

ABSTRACT: This preregistered (CRD42021223379) systematic review and meta-analysis aimed to characterize the placebo and nocebo responses in placebo-controlled randomized clinical trials (RCTs) on painful diabetic neuropathy (PDN), updating the previous literature by a decade. Four databases were searched for PDN trials published in the past 20 years, testing oral medications, adopting a parallel-group design. Magnitude of placebo or nocebo responses, Cochrane risk of bias, heterogeneity, and moderators were evaluated. Searches identified 21 studies (2425 placebo-treated patients). The overall mean pooled placebo response was -1.54 change in the pain intensity from baseline [95% confidence interval (CI): -1.52, -1.56, I 2 = 72], with a moderate effect size (Cohen d = 0.72). The pooled placebo 50% response rate was 25% [95% CI: 22, 29, I 2 = 50%]. The overall percentage of patients with adverse events (AEs) in the placebo arms was 53.3% [95% CI: 50.9, 55.7], with 5.1% [95% CI: 4.2, 6] of patients dropping out due to AEs. The year of study initiation was the only significant moderator of placebo response (regression coefficient = -0.06, [95% CI: -0.10, -0.02, P = 0.007]). More recent RCTs tended to be longer, bigger, and to include older patients (N = 21, rs = 0.455, P = 0.038, rs = 0.600, P = 0.004, rs = 0.472, P = 0.031, respectively). Our findings confirm the magnitude of placebo and nocebo responses, identify the year of study initiation as the only significant moderator of placebo response, draw attention to contextual factors such as confidence in PDN treatments, patients' previous negative experiences, intervention duration, and information provided to patients before enrollment.

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.

Reporting of auditory symptoms over time: (in)consistencies, expectations and the nocebo effect.

Objective: Consistent symptom reporting for conditions like tinnitus that do not have an associated sign is critical for evaluating severity and intervention effectiveness, and for interpreting research findings. There is little research examining reporting of tinnitus and hearing difficulty over time. We address this here by comparing reported hearing difficulty and tinnitus at two time-points.Design: A cross-sectional study comparing symptom reporting in March 2019 and August/September 2021 using data from two online surveys of the same cohort. Although each survey was designed to address a different question, both asked about symptoms of tinnitus and hearing difficulties and enabled this exploratory analysis.Study sample: 6881 members of the UK general public aged 18+ years.Results: Inconsistent reporting was evident - many participants who reported experiencing tinnitus and/or hearing difficulties in 2019, said in 2021 that they had never had such symptoms before. Additionally, reports of new tinnitus/hearing difficulties in 2021 were unexpectedly high, equating to 18-month incidence rates of 13.6% and 11.7%, respectively.Conclusions: Psychosocial factors, expectations and context impact symptom reporting. This should be considered when treating patients and interpreting research findings. Using real-time data collection methods could thus provide a better understanding of experiences of tinnitus and hearing.

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.

A new experimental rat model of nocebo-related nausea involving double mechanisms of observational learning and conditioning.

AIM: The nocebo effect, such as nausea and vomiting, is one of the major reasons patients discontinue therapy. The underlying mechanisms remain unknown due to a lack of reliable experimental models. The goal of this study was to develop a new animal model of nocebo-related nausea by combining observational learning and Pavlovian conditioning paradigms. METHODS: Male Sprague-Dawley rats with nitroglycerin-induced migraine were given 0.9% saline (a placebo) or LiCl (a nausea inducer) following headache relief, according to different paradigms. RESULTS: Both strategies provoked nocebo nausea responses, with the conditioning paradigm having a greater induction impact. The superposition of two mechanisms led to a further increase in nausea responses. A preliminary investigation of the underlying mechanism revealed clearly raised peripheral and central cholecystokinin (CCK) levels, as well as specific changes in the 5-hydroxytryptamine and cannabinoid systems. Brain networks related to emotion, cognition, and visceral sense expressed higher c-Fos-positive neurons, including the anterior cingulate cortex (ACC), insula, basolateral amygdala (BLA), thalamic paraventricular nucleus (PVT), hypothalamic paraventricular nucleus (PVN), nucleus tractus solitarius (NTS), periaqueductal gray (PAG), and dorsal raphe nucleus-dorsal part (DRD). We also found that nausea expectances in the model could last for at least 12 days. CONCLUSION: The present study provides a useful experimental model of nocebo nausea that might be used to develop potential molecular pathways and therapeutic strategies for nocebo.

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.

The nocebo effect across health outcomes: A systematic review and meta-analysis.

OBJECTIVE: The nocebo effect represents a growing concern in clinical settings. Nocebo effects occur when the treatment context generates negative expectancies that trigger the experience or worsening of negative symptoms beyond any effects attributable to the treatment itself. Despite being identified in a range of outcomes and conditions, from pain to Parkinson's disease, there has not been an attempt to systematically quantify the nocebo effects across health outcomes. The purpose of the present review was thus to systematically review and meta-analyze the nocebo literature to quantify the size of the nocebo effect across outcomes and examine which factors moderate the size of the nocebo effect, including process of induction, treatment type, or health outcome. METHOD: Systematic searches of PubMed, PychInfo, Medline, and Web of Science identified 130 (n = 8,219) independent eligible studies. To be included, studies had to include both a nocebo and control group/condition, which were compared to isolate the nocebo effect size. RESULTS: Overall, the magnitude of the nocebo effect was medium (g = 0.522) and highly heterogeneous. Two key moderators emerged: health outcome and process of induction. Here, the nocebo effect was medium for most somatic outcomes and affect, with no significant effect on worsening cognitive performance. Further, inducing nocebo effects through instruction in combination with conditioning produced larger nocebo effects. CONCLUSIONS: The present review suggests nocebo effects can be reliably induced across somatic health outcomes, and interventions that target the effect of instructions will be of critical importance to reducing the occurrence of nocebo effects. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Use of Authorized Concealment to Minimize Nocebo Side Effects: A Survey of US Public Attitudes.

INTRODUCTION: To minimize nocebo effects, it may be possible to employ authorized concealment, in which clinicians tell patients about the nocebo phenomenon and ask if they would prefer not to be informed about mild treatment side effects. OBJECTIVE: The objective of the study was to understand public evaluations of authorized concealment for reducing nocebo effects. METHODS: An online cross-sectional survey was completed by a demographically diverse US national community sample between June 2 and 6, 2023. Participants were 1,012 adults residing in 48 states, ages ranging from 18 to 94 (mean = 43.2), 65.4% regularly taking medication, and 66.6% reporting a chronic physical or mental health condition. After learning about nocebo effects, participants rated and estimated their likelihood of consenting to four potential methods for authorized concealment of mild side effects. The four methods were ranked for preference and ranked again with the options of (1) receiving all side-effect information and (2) having the opportunity to select among disclosure methods. RESULTS: A majority of participants (86.2%) positively endorsed at least one authorized concealment method and 88.2% estimated they would consent to at least one method. Authorized concealment in which individuals learned only the most common side effects or had side-effect information available online received more positive ratings and rankings. A final ranking yielded preferences for receiving all side-effect information (30.4%) and having the opportunity to select side-effect disclosure method (31.8%). CONCLUSIONS: Our study suggests that many in the public could be open to authorized concealment for mild side effects when it is explained in reference to nocebo effects.