The Role of Attention in Placebo and Nocebo Effects.

BACKGROUND: Although some existing models propose that attention may be crucially implicated in placebo/nocebo effects, empirical research on this aspect remains limited and scattered. PURPOSE: This systematic review aims to provide an inclusive overview of studies that have either directly manipulated or assessed attention within the context of placebo and nocebo procedures so to gain a synthetized picture of the role of this variable in placebo/nocebo effects. Importantly, only studies in which attention represented a mechanism or mediator of the placebo/nocebo response, and not a primary outcome, were included. METHODS: A systematic search was conducted across multiple databases, including PubMed, Scopus, PsycINFO, Web of Science, and Embase, to identify peer-reviewed studies. These studies were subjected to methodological evaluation and eligibility criteria for inclusion. RESULTS: We identified and classified 12 studies into three categories based on their focus: (i) those that directly assessed attention, (ii) those that directly manipulated participants' attention, and (iii) those that combined both a direct manipulation and assessment of attention. In all selected studies attention acted as a mechanism or mediator of the placebo/nocebo response, and was not considered a primary outcome of the placebo/nocebo manipulation. CONCLUSIONS: The synthesis of the included studies reveals that the role of attention in placebo and nocebo effects is still a topic of debate, marked by variations in how attention is conceptualized and measured. Results suggest that attention has significant clinical implications, particularly in optimizing therapeutic efficacy by directing patients' focus toward signs of healing and away from indicators of illness or distress. To advance our understanding, future research should explore these attentional mechanisms, in conjunction with neurophysiological correlates.

To date, empirical research on the role of attention in placebo/nocebo effects remains scarce and inconclusive. The aim of this systematic review is to offer an overview of studies that have either directly manipulated or assessed attention as a mechanism or mediator of placebo/nocebo responses. Peer-review studies were subjected to methodological evaluation and eligibility criteria, and 12 studies were selected and classified into 3 categories based on their focus: (i) those that directly assessed attention, (ii) those that directly manipulated participants' attention, and (iii) those that combined both a direct manipulation and assessment of attention. The synthesis of the included studies points to the nuanced methodological approaches to the study of the role of attention in placebo and nocebo effects, marked by variations in how this variable is conceptualized and measured. Overall, results support the idea that placebo/nocebo effects are not always a direct byproduct of expectations, with attention acting as an important factor to consider when exploring this relationship. Particularly, attention plays an important role in optimizing therapeutic efficacy by directing patients' focus toward signs of healing and away from indicators of illness or distress.

Manipulating placebo analgesia and nocebo hyperalgesia by changing brain excitability.

Harnessing placebo and nocebo effects has significant implications for research and medical practice. Placebo analgesia and nocebo hyperalgesia, the most well-studied placebo and nocebo effects, are thought to initiate from the dorsal lateral prefrontal cortex (DLPFC) and then trigger the brain's descending pain modulatory system and other pain regulation pathways. Combining repeated transcranial direct current stimulation (tDCS), an expectancy manipulation model, and functional MRI, we investigated the modulatory effects of anodal and cathodal tDCS at the right DLPFC on placebo analgesia and nocebo hyperalgesia using a randomized, double-blind and sham-controlled design. We found that compared with sham tDCS, active tDCS could 1) boost placebo and blunt nocebo effects and 2) modulate brain activity and connectivity associated with placebo analgesia and nocebo hyperalgesia. These results provide a basis for mechanistic manipulation of placebo and nocebo effects and may lead to improved clinical outcomes in medical practice.

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.

The influence of psychological traits and prior experience on treatment expectations.

BACKGROUND: Placebo and nocebo responses are modulated by the treatment expectations of participants and patients. However, interindividual differences predicting treatment expectations and placebo responses are unclear. In this large-scale pooled analysis, we aim to investigate the influence of psychological traits and prior experiences on treatment expectations. METHODS: This paper analyses data from six different placebo studies (total n = 748). In all studies, participants' sociodemographic information, treatment expectations and prior treatment experiences and traits relating to stress, somatization, depression and anxiety, the Big Five and behavioral inhibition and approach tendencies were assessed using the same established questionnaires. Correlation coefficients and structural equation models were calculated to investigate the relationship between trait variables and expectations. RESULTS: We found small positive correlations between side effect expectations and improvement expectations (r = 0.187), perceived stress (r = 0.154), somatization (r = 0.115), agitation (r = 0.108), anhedonia (r = 0.118), and dysthymia (r = 0.118). In the structural equation model previous experiences emerged as the strongest predictors of improvement (ß = 0.32, p = .005), worsening (ß = -0.24, p = .005) and side effect expectations (ß = 0.47, p = .005). Traits related to positive affect (ß = - 0.09; p = .007) and negative affect (ß = 0.04; p = .014) were associated with side effect expectations. DISCUSSION: This study is the first large analysis to investigate the relationship between traits, prior experiences and treatment expectations. Exploratory analyses indicate that experiences of symptom improvement are associated with improvement and worsening expectations, while previous negative experiences are only related to side effect expectations. Additionally, a proneness to experience negative affect may be a predictor for side effect expectation and thus mediate the occurrence of nocebo responses.

Can contagious itch be affected by positive and negative suggestions?

Contagious itch can be evoked by observing people scratching. Verbal suggestions about to-be-received itch can influence itch intensity, as shown by placebo research, but it is unknown whether this extends to contagious itch. The current study aimed to replicate prior findings that listening to scratching and rubbing sounds elicits contagious itch, and to investigate whether suggestions can modulate this process. Healthy participants (n = 140) received positive or negative suggestions about itch in response to the sounds (aimed to decrease or increase expected itch, respectively), or no specific suggestions as a control. Participants listened to a number of audio fragments with scratching and rubbing sounds. The amount of expected itch as well as itch sensation after each audio fragment were measured by self-report. Suggestions had no effect on the expected itch. Both rubbing and scratching sounds significantly elicited itch in all groups. Scratching sounds induced more itch than rubbing sounds exclusively in the control group. These findings indicate that short suggestions might be not effective enough to modify the expectations of people regarding contagious itch. Furthermore, suggestions modulate contagious itch to some degree, but not in the hypothesized direction. Potential similarities and differences in the neurobiological mechanisms of contagious itch and nocebo effects are discussed.

What Should Clinicians Tell Patients about Placebo and Nocebo Effects? Practical Considerations Based on Expert Consensus.

INTRODUCTION: Clinical and laboratory studies demonstrate that placebo and nocebo effects influence various symptoms and conditions after the administration of both inert and active treatments. OBJECTIVE: There is an increasing need for up-to-date recommendations on how to inform patients about placebo and nocebo effects in clinical practice and train clinicians how to disclose this information. METHODS: Based on previous clinical recommendations concerning placebo and nocebo effects, a 3-step, invitation-only Delphi study was conducted among an interdisciplinary group of internationally recognized experts. The study consisted of open- and closed-ended survey questions followed by a final expert meeting. The surveys were subdivided into 3 parts: (1) informing patients about placebo effects, (2) informing patients about nocebo effects, and (3) training clinicians how to communicate this information to the patients. RESULTS: There was consensus that communicating general information about placebo and nocebo effects to patients (e.g., explaining their role in treatment) could be beneficial, but that such information needs to be adjusted to match the specific clinical context (e.g., condition and treatment). Experts also agreed that training clinicians to communicate about placebo and nocebo effects should be a regular and integrated part of medical education that makes use of multiple formats, including face-to-face and online modalities. CONCLUSIONS: The current 3-step Delphi study provides consensus-based recommendations and practical considerations for disclosures about placebo and nocebo effects in clinical practice. Future research is needed on how to optimally tailor information to specific clinical conditions and patients' needs, and on developing standardized disclosure training modules for clinicians.

Danger! Negative memories ahead: the effect of warnings on reactions to and recall of negative memories.

A trigger warning is an alert that upcoming material containing distressing themes might "trigger" the details and emotion associated with a negative memory to come to mind. Warnings supposedly prevent or minimise this distress. But, do warnings really have this effect? To simulate the experience described above, here, we examined whether warning participants-by telling them that recalling a negative event would be distressing-would change characteristics associated with the immediate and delayed recall of a negative event (such as phenomenology e.g., vividness, sense of reliving), compared to participants who we did not warn. Generally, we found that time helps to heal the "emotional wounds" associated with negative memories: negative characteristics-such as emotion, vividness etc.-faded over time. However, the event's emotional impact (the frequency of experiences related to the event such as "I had trouble staying asleep"), subsided less over a two-week delay for participants who were warned in the first session. Our findings suggest that warning messages may prolong the negative characteristics associated with memories over time, rather than prepare people to recall a negative experience.

Positive Treatment Expectancies Reduce Clinical Pain and Perceived Limitations in Movement Ability Despite Increased Experimental Pain: A Randomized Controlled Trial on Sham Opioid Infusion in Patients with Chronic Back Pain.

BACKGROUND: Increasing evidence for the efficacy of analgesic placebo effects in laboratory studies with healthy persons raises the question whether placebos could be used to improve the treatment of pain patients. Expectancies play a central role in shaping analgesic placebo but also nocebo effects. OBJECTIVES: We investigated to what extent a sham opioid infusion (saline solution) produces sustained clinically relevant placebo and nocebo effects in chronic back pain patients. METHODS: Fifty-nine patients received the sham opioid infusion applied via a large drain dressing and were compared to 14 control patients without intervention (natural history, NH) while experimental pain stimuli were applied. All subjects were told that the infusion would decrease pain although in rare cases pain increase would be possible (induction of expectancy). In addition, conditioning was introduced where the participants either experienced a decrease in experimental pain (n = 17; placebo conditioning), an increase (n = 21; nocebo conditioning), or no change (n = 21, no conditioning). RESULTS: Compared to the NH group, all infusion groups showed positive treatment expectancies and significantly (p < 0.001) reduced clinical back pain (primary outcome) and pain-related disability (secondary outcome, assessed by self-reported functional capacity and perceived impairment of mobility). Even the nocebo conditioned group experiencing increased experimental pain developed positive treatment expectancies followed by reduced pain experience. Positive treatment expectancies and relief in clinical back pain were significantly positively correlated (r = 0.72, p < 0.01). CONCLUSIONS: These findings suggest that it may be beneficial to explicitly shape and integrate treatment expectancies into clinical pain management.

Assessing clinical and psychological features: who are patients showing a nocebo re-action during the drug challenge test?

Summary: The nocebo reaction, namely the undesirable effect of an inert substance (placebo), is a phenomenon rarely investigated in literature. A better knowledge of this reaction may help clinicians in the management of these patients in clinical practice. Patients with drug adverse reactions (ADR) undergoing the drug challenge test are an ideal model for studying the nocebo effect, and the study aims to investigate their clinical and psychological features. One hundred and twenty patients (Mage = 46.59, SD = 15.5; 82% female), of which 90 non responders and 30 with nocebo reactions (25%) were recruited, and completed a battery of psychological measures: State-Trait Anxiety Inventory X1-X2, Beck Depression Inventory II, Symptoms Checklist-90-R, Difficulties in Emotion Regulation Scale, Toronto Alexithymia Scale. Clinical features (individual characteristics and ADR clinical history) were collected by clinicians. The results show that older age (p = 0.002), low level of education (p = 0.039) and a depressive tendency (p = 0.030) appear to be potential risk factors for nocebo effects. Although none of the features related to the previous clinical history appear to represent a risk factor for the nocebo reactions (p minor 0.05), significant correlations between some of the clinical and psychological characteristics considered (p values from 0.005 to 0.042) help to better delineate the profile of these reactive patients. A specific training of the sanitary team about psychological aspects is recommendable.

Contextual factors triggering placebo and nocebo effects in nursing practice: Findings from a national cross-sectional study.

AIMS AND OBJECTIVES: To describe contextual factors (CFs) used by nurses to increase placebo and to prevent nocebo effects. BACKGROUND: Placebo effects have been studied in the nursing discipline, but nocebo effects still remain unexplored. Recently, a set of CFs functioning as triggers of placebo/nocebo effects has been described; however, its use in daily care has never been documented to date. DESIGN: A national cross-sectional survey, according to the Checklist for Reporting Results of Internet E-Surveys guidelines and STrengthening the Reporting of OBservational Studies in Epidemiology (STROBE), was performed in 2016. METHODS: A wide sample of Italian nurses belonging to four national associations was involved. A questionnaire based on CFs literature was developed and administered through the SurveyMonkey Software® exploring: (a) CFs definition, (b) beliefs, (c) case-by-case frequency of use, (d) circumstances of application, (e) clinical conditions where participants perceived their potential beneficial effects, (f) ethical implications and (g) communication issues with the patient. RESULTS: Out of 1,411 eligible nurses, 455 answered (32.2%) and 425 questionnaires (30.1%) were valid for the analysis. A total of 211 nurses (49.6%) defined the CFs as an intervention with a possible aspecific effect; participants believed in the CFs (2.91; 95%CI 2.88-2.94), using them >2 times/month, mainly in addition to a nursing intervention to optimise clinical outcomes (n = 79; 18.6%). Psychological and physiological therapeutic effects have been perceived mainly in chronic pain (n = 259; 60.9%) and insomnia (n = 243; 57.2%). According to participants, CFs have been reported as ethically acceptable when exerting beneficial psychological effects (n = 148; 34.8%); however, 103 (24.2%) of nurses did not communicate to the patient when CFs were used. CONCLUSIONS: Nurses are aware of CFs as elements to increase the placebo and prevent the nocebo effects in concomitance with evidence-based nursing interventions. RELEVANCE TO CLINICAL PRACTICE: The CFs valued by nurses and experienced as effective are mainly based upon the internal quality of the nurse and the quality of the relationship between the nurse and the patient. These qualities require a large personal investment; therefore, nurses should be supported in developing these qualities since their nursing graduation.

Placebo and nocebo responses in drug trials of epilepsy.

Placebo response can be defined as any therapeutic change on placebo, while the nocebo response is any ill effect during placebo exposure. Several meta-analytic approaches have investigated the extent of placebo response in randomized, placebo-controlled, clinical trials of focal epilepsies. Placebo response rates (proportion of patients with ≥50% improvement of seizures versus baseline) ranging from 9.9% up to 15.2% have been reported. Interestingly, a sham response of 15.8% has been noted in trials of transcranial magnetic stimulation. Recently, nocebo response rates of 60.3% and 3.9% were noted, which were defined as the proportion of patients with adverse events (AEs) and those withdrawing because of intolerable AEs, respectively. Factors which were found to influence placebo response were as follows: the year of publication (with more recent studies showing higher rates of placebo response), some clinical characteristics of recruited patients (lower placebo response rates with a history of 7 or more prior lifetime AEDs, a high baseline seizure frequency, prior epilepsy surgery, and higher age at diagnosis), trial design and statistical analysis, and whether studies have been conducted in children or adults. Furthermore, placebo and nocebo rates were correlated with respective seizure outcome and adverse events of the experimental AED. Several mechanisms of placebo and nocebo responses are discussed. Specifically, the role of positive or negative expectations of patients and of investigators may influence the placebo and the nocebo response. Finally, recommendations are given on how to address placebo and nocebo responses in clinical practice.

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

BACKGROUND: Nocebo effects are unavoidable in randomized clinical trials. We aimed to assess the magnitude of nocebo effects and explore the influencing factors in chronic constipation. METHODS: We searched the PubMed, Embase, and Cochrane Library databases up to July 2022. Randomized, placebo-controlled trials investigating interventions in chronic constipation were included. We conducted a random effects meta-analysis of the proportion of adverse events (AEs) in placebo-treated participants and evaluated the effect of trial characteristics on nocebo effects. KEY RESULTS: We identified 20,204 studies from the databases, of which 61 were included in the final analysis. The pooled placebo AE rate was 30.41%, and AE-related withdrawal rate was 1.53%. The most commonly reported AEs were headache (5.67%), diarrhea (4.45%), abdominal pain (3.98%), nasopharyngitis (3.39%), nausea (3.36%), and flatulence (2.95%). The placebo AE rate was lower in trials conducted in Asia compared to those in Europe, North America, and international trials. It was also lower in trials diagnosed by Rome III compared to clinician's opinion and Rome II. Additionally, the placebo AE rate was lower in single-center trials compared to multicenter trials, lower in 5-8 weeks therapy compared to 9-12 weeks therapy, lower in participants with FC compared to those with IBS-C and CC, lower in trials with 2 arms compared to 3 arms, and higher in trials with prokinetic drugs compared to secretagogues and laxatives. CONCLUSIONS & INFERENCES: The placebo AE rate was 30.41% in patients with chronic constipation. Based on our findings, we recommend that researchers take the nocebo effects into consideration when designing and conducting clinical trials and adopt specific measures to mitigate the negative influence of nocebo effects.

Placebo 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 role of self-reported and physiological stress in nocebo hyperalgesia.

Negative expectations can increase pain sensitivity, leading to nocebo hyperalgesia. However, the physiological and psychological factors that predispose individuals to this phenomenon are still not well understood. The present study examined whether stress induced by a social stressor affects nocebo hyperalgesia, and whether this effect is mediated by self-reported and physiological stress responses. We recruited 52 healthy participants (15 men) who were randomly assigned to either the Trier Social Stress Test (TSST) or a control condition (a friendly version of the TSST). Nocebo hyperalgesia was induced using negative suggestions combined with a validated pain conditioning paradigm. We assessed self-reported (anxiety and stress) and physiological (cortisol, alpha-amylase, heart rate, and skin conductance) responses to stress. Both groups exhibited significant nocebo hyperalgesia. The stress group showed higher levels of anxiety, self-reported stress, and cortisol levels compared to the control group while no significant differences were found in other physiological markers. The stress and control groups did not differ in the magnitude of nocebo hyperalgesia, but anxiety levels partially mediated the effects of the stress test on nocebo hyperalgesia. Our findings suggest that an external social stressor does not directly affect nocebo hyperalgesia, but that increased anxiety due to the stressor enhances its magnitude. Thus, it may be worthwhile to investigate whether reducing stress-related anxiety in clinical settings would help alleviate nocebo effects.

Role of Psychosomatic Symptoms in COVID-19 Vaccine Hesitancy.

Vaccination against COVID-19 is one of the highly effective preventative strategies to reduce morbidity and mortality associated with COVID-19 infection. The rapid approval of COVID-19 vaccination due to the raging pandemic, media coverage, anti-vaccination groups, and concerns about adverse effects associated with vaccination has given rise to COVID-19 vaccine hesitancy. Current evidence suggests that psychosomatic and nocebo-related adverse effects account for a significant proportion of common adverse effects following COVID-19 vaccination. The most common adverse effects are headache, fatigue, and myalgia, which are highly prone to nocebo effects. In our review article, we discuss the role of psychosomatic and nocebo effects in COVID-19 vaccination-related hesitancy, predictors of such effects, and strategies to reduce vaccine hesitancy. General education regarding psychosomatic and nocebo effects and specialized education for at-risk populations may reduce psychosomatic and nocebo-related adverse effects following COVID-19 vaccination, ultimately reducing hesitancy.

Do individual psychological characteristics predict induction and generalization of nocebo and placebo effects on pain and itch?

Background: Nocebo and placebo effects, i.e., adverse or beneficial treatment effects, respectively, putatively due to expectancies can modulate pain and itch. These effects can generalize within the pain or itch modality. Predicting the induction and generalization of these effects can be helpful in clinical practice. This study aims to investigate whether psychological characteristics related to the fear-avoidance model predict the induction and generalization of nocebo and placebo effects on pain and itch in young healthy participants. Methods: Data from two previous experiments were analyzed. In Experiment 1, we induced nocebo and placebo effects on heat pain and tested generalization to pressure pain and to cowhage-evoked itch (n = 33 in a nocebo group, n = 32 in a placebo group). In Experiment 2, we induced nocebo effects on cowhage-evoked itch and tested generalization to mechanical itch and to mechanical touch (n = 44). Potential predictors were anxiety- and stress symptoms, attention to pain/itch, and pain/itch catastrophizing. Multiple regression analyses were performed. Results: For nocebo effects, none of the individual psychological characteristics significantly predicted induction of nocebo effects nor their generalization. For placebo effects, only less stress symptoms, lower attention to pain, and higher pain catastrophizing weakly predicted a stronger generalization of placebo effects from heat pain to pressure pain. Conclusion: The tested psychological characteristics may not play an important role in the induction and generalization of nocebo and placebo effects in healthy individuals. However, firm conclusions cannot be drawn with the current sample. Future studies should validate findings in larger and more diverse samples.

Counterconditioning as Treatment to Reduce Nocebo Effects in Persistent Physical Symptoms: Treatment Protocol and Study Design.

Persistent physical symptoms have a high prevalence and a large impact for patients and society. To date, treatment effects for these symptoms are often limited. Nocebo effects (i.e., negative outcomes that are not attributable to active treatment components) have a substantial influence on treatment success and can be established via learning through classical conditioning. Therefore, interventions aimed at reducing nocebo effects by means of counterconditioning, in which an alternative association (inhibiting the previous association) is learned, could be a promising method for improving physical symptoms. In experimental studies, counterconditioning has been shown promising in reducing experimentally-induced nocebo effects on pain and itch. Application of counterconditioning procedures to reduce nocebo effects on clinical symptoms has yet to be researched. This paper provides a protocol of a 6-week counterconditioning intervention aimed at reducing nocebo effects and clinical pain in patients with fibromyalgia. A study in patients with fibromyalgia is proposed to examine the feasibility and potential effectiveness of this counterconditioning intervention as a novel treatment method for reducing nocebo effects and generalization to clinical pain symptoms. Results can help design an optimized treatment protocol for reducing nocebo effects, based on the experiences of participants and the first indications of treatment efficacy.

Sharing clinical notes, and placebo and nocebo effects: Can documentation affect patient health?

This paper connects findings from the field of placebo studies with research into patients' interactions with their clinician's visit notes, housed in their electronic health records. We propose specific hypotheses about how features of clinicians' written notes might trigger mechanisms of placebo and nocebo effects to elicit positive or adverse health effects among patients. Bridging placebo studies with (a) survey data assaying patient and clinician experiences with portals and (b) randomized controlled trials provides preliminary support for our hypotheses. We conclude with actionable proposals for testing our understanding of the health effects of access to visit notes.

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

Background: In neck pain treatment, many therapies are focused on etiology, while it is well-known that placebo analgesia is also present in these therapies. The specific efficacy for etiology may be underestimated by ignoring their actual placebo effect. In this study, a logistic regression analysis is used to explore the risk factors causing different placebo responses in patients with neck pain among two RCTs. The probability of the placebo effect is predicted based on these risk factors. Methods: Trial A and Trial B were similarly designed, randomized, double-/single-blind, placebo-controlled trials in patients treating neck pain with Qishe pill or Shi-style manipulation. Both studies set a placebo pill twice a day or traction for every other day as control. For further analyses on the placebo effect in neck pain management, logistic regression was used to assess subgroup-placebo interactions. The odds ratio assessed a significant influence on the placebo effect. Results: In this pooled analysis, the total number of patients recruited for these two studies was 284, of which 162 patients received placebo treatment (placebo drug or traction for every other day). No statistically significant differences are found at baseline between the participants with placebo effect and non-placebo effect in the gender, age, and disease duration except in VAS and NDI at the initial time. There are numerically more patients with placebo effect in the shorter disease duration subgroup (< 4 months [76%]), higher initial VAS subgroup (>60 mm [90%]), and worse initial NDI subgroup (>24 [72%]) compared with the gender and age subgroup. An ROC curve is established to assess the model-data fit, which shows an area under the curve of 0.755 and a 95% confidence interval of 0.677-0.830. Participants who show placebo effect after 2 weeks have significantly lower VAS scores after 4 weeks, while there is no significant difference in NDI improvement between the two groups after 4 weeks. Conclusion: Neck pain patients with shorter disease duration are more likely to overscore their pain severity, because of their less experience in pain perception, tolerance, and analgesia expectation.