Prescribing Placebos: An Experimental Examination of the Role of Dose, Expectancies, and Adherence in Open-Label Placebo Effects

Preventing medication nonadherence: a framework for interventions to support early engagement with treatment

ABSTRACTMedication nonadherence is common and results in avoidable morbidity, mortality, and burdens on healthcare systems. This paper proposes a preventative approach to medication nonadherence. We consider existing evidence on the prevalence and determinants of nonadherence early in a patient's medication-taking journey, and map these to potential opportunities for intervention. Many patients stop taking a new medication soon after they are prescribed it, often not collecting the medication. Early patterns of nonadherence are linked to later nonadherence via processes such as habit formation and symptom experiences. Known predictors of nonadherence may be present before someone starts a new treatment, when patients experience disruption to their lives and identity due to illness. Healthcare professionals typically have contact with patients around this time. We argue that it may be possible to prevent medication nonadherence: at the population level; by optimising the prescription process; and through low- and high-intensity interventions for patients with identified early barriers. We give examples of specific interventions and tools that might be needed to operationalise this approach in practice and propose new directions for research to promote early engagement with medication to prevent nonadherence.

Working with patients' treatment expectations - what we can learn from homeopathy

The usual homeopathic remedy, "globules," does not contain any pharmacologically active ingredient. However, many patients and practitioners report beneficial effects of homeopathic treatment on various health outcomes. Experimental and clinical research of the last two decades analyzing the underlying mechanisms of the placebo effect could explain this phenomenon, with patients' treatment expectations as the predominant mechanism. Treatment expectations can be optimized through various factors, such as prior information, communication, and treatment context. This narrative review analyses how homeopathy successfully utilizes these factors. Subsequently, it is discussed what evidence-based medicine could learn from homeopathic practice to optimize treatment expectations (e.g., using an empathic, patient-centered communication style, deliberately selecting objects in practice rooms, or using clear treatment rituals and salient contextual stimuli) and thereby treatment effectiveness. Homeopathic remedy does not work beyond the placebo effect but is recommended or prescribed as an active treatment by those who believe in it. Thus, practitioners need to understand the manner in which homeopathy (as an example of inert treatment) works and are advised to reintegrate its underlying effective placebo mechanisms into evidence-based medicine. This promises to increase treatment efficacy, tolerability, satisfaction, and compliance with evidence-based treatments, and addresses the desires patients are trying to satisfy in homeopathy in an ethical, fully informed way that is grounded in evidence-based medicine.

Change in pain expectations but no open-label placebo analgesia: An experimental study using the heat pain paradigm

BACKGROUND

Open-label placebos (OLP) prescribed without deception and with a convincing rationale have been shown to evoke powerful treatment effects. Patients' treatment expectations seem to influence the magnitude of the effect.

OBJECTIVE

We examined if two different OLP rationales increased pain tolerance and reduced pain intensity and unpleasantness in a standardized heat pain experiment.

METHODS

Participants (N = 71) who self-reported reoccurring pain for at least the last 3 months were randomly assigned to one of three groups. We compared a personal-emotional and a scientific-matter-of-fact rationale with a control group (CG) that received the same placebo without any rationale. The rationale suggested a desensitizing effect on pain perception and improved pain coping of the placebo, whereas in the CG it was introduced as an ointment for measurement. The primary outcomes were pre-post changes in pain tolerance, expected and experienced pain intensity and unpleasantness.

RESULTS

Participants showed a decrease in expected pain intensity, but not expected pain unpleasantness for both rationales. There were no differences in pain tolerance and experienced pain intensity and unpleasantness.

CONCLUSIONS

Our study suggests that evoking positive treatment expectations is not sufficient to elicit an OLP response. Possibly, the magnitude of expectations change in this study was not powerful enough to evoke an OLP effect. Additionally, it is possible that OLP effects in pain are unrelated to positive treatment expectations. The failure of OLP in our study is in contrast to a number of previous studies examining the effects of OLP in experimental and clinical pain.

SIGNIFICANCE

This study provides evidence that positive treatment expectations are not sufficient to evoke an open-label placebo effect in a standardized heat pain experiment. We showed that two different rationales improved participants treatment expectations, but failed to evoke a placebo effect in comparison to a control group that received the same placebo, labelled as an ointment to improve measurement quality.

Choice over placebo administration enhances open-label placebo hypoalgesia

ABSTRACT

Many studies indicate that deceptively administered placebos can improve pain outcomes. However, the deception involved presents an ethical barrier to translation because it violates informed consent and patient autonomy. Open-label placebos (OLPs), inert treatments that are openly administered as placebos, have been proposed as an ethically acceptable alternative. Early studies have suggested that OLP can improve pain outcomes, but important questions remain as to how to maximise OLP hypoalgesia to improve treatment outcomes in pain patients. This study investigated whether providing choice over when to administer an OLP treatment has the capacity to enhance OLP hypoalgesia using an electrocutaneous pain paradigm. One hundred thirty-two healthy volunteers were randomised to 3 types of treatment: OLP with choice, OLP without choice, and no treatment (natural history). The OLP groups were further randomised such that half were tested with a consistent pain intensity and the other half were tested with variable pain intensity to mimic day-to-day variability in pain intensity in health settings. The results indicated that treatment provided with choice exhibited greater OLP hypoalgesia than that provided without choice and that greater expectancy mediated this effect. Of interest, there was no evidence for OLP hypoalgesia without choice relative to natural history. Furthermore, variability in pain intensity did not affect OLP hypoalgesia. The current findings present novel evidence that choice over treatment administration may be a cheap and effective strategy for boosting the efficacy of OLPs in the clinical care of pain.

Practitioner warmth and empathy attenuates the nocebo effect and enhances the placebo effect

Augmented patient-practitioner interactions that enhance therapeutic alliance can increase the placebo effect to sham treatment. Little is known, however, about the effect of these interactions on maladaptive health outcomes (i.e., the nocebo effect). Healthy participants (N = 84) were randomised to a 3-day course of Oxytocin nasal drops (actually, sham treatment) in conjunction with a high-warmth interaction (Oxy-HW: N = 28), a low-warmth interaction (Oxy-LW: N = 28) or to a no treatment control group (NT: N = 28). All participants were informed that the Oxytocin treatment could increase psychological well-being but was associated with several potential side effects. Treatment-related side effects, unwarned symptoms, and psychological well-being were measured at baseline and all post-treatment days. Side effect reporting was increased in the Oxy-LW condition compared to the other groups across all days. Conversely, increased psychological well-being was observed in the Oxy-HW condition, relative to the other conditions, but only on Day 1. Among those receiving treatment, positive and negative expectations, and treatment-related worry, did not vary by interaction-style, while psychological well-being and side effect reporting were inversely associated at the level of the individual. Results have important implications for practice, suggesting poorer quality interactions may not only reduce beneficial health outcomes but also exacerbate those that are maladaptive.

Effects of (non)deceptive placebos on reported sleep quality and food cue reactivity

A lack of sleep can increase appetite, particularly for high-calorie food. The current study tested the effects of an open-label placebo for improving sleep quality and reducing food cue reactivity. In open-label placebo interventions, placebo recipients are informed that they are receiving a placebo without a pharmacologically active substance. Participants (n = 150) were randomly allocated to one of three groups that received either an open-label placebo to improve sleep quality, a deceptive placebo ("melatonin"), or no placebo. The placebo was administered daily before bedtime for 1 week. Sleep quality and reactivity to high-calorie food cues (appetite, visual attention to food images) were assessed. The deceptive placebo (but not the open-label placebo) reduced reported sleep-onset latency. The open-label placebo decreased perceived sleep efficiency. The placebo interventions did not change food cue reactivity. This study demonstrated that open-label placebos do not present an alternative to deceptive placebos for improving sleep quality. The undesirable open-label placebo effects found warrant further exploration.

Boosting open-label placebo effects in acute induced pain in healthy adults (BOLPAP-study): study protocol of a randomized controlled trial

Introduction

Pain is a highly prevalent symptom in the hospital setting, but treatment options remain limited. Harnessing the placebo effect in an ethical manner could provide a new possibility to reduce pain in clinical practice. So called open-label placebos (OLP) have been shown to elicit significant effects in reducing acute pain. But, before implementation, more knowledge concerning the properties of OLPs is needed. This study aims to assess the duration of analgesic effects from OLP and to determine the possibility of boosting such effects.

Methods and analysis

This is the protocol of an ongoing (first patient enrolled in March 2023) single-site randomized trial investigating OLPs in two parts (i.e., substudies). In both parts, pain will be induced in healthy adults using an intradermal electrical stimulation model. Participants in Part 1 will have two study visits: An interventional visit with one OLP injection accompanied by an evidence-based treatment rationale and a control visit with no treatment. For Part 2, participants will be randomized into three groups: (1) A fixed-time "Booster" group including one single repetition of the OLP injection at a fixed time point, (2) an on-demand "Booster" group including one single repetition of the OLP injection on-demand, and (3) a control group who will receive just one OLP injection. Differences in pain ratings over time (using the Numeric Rating Scale) will be analyzed with several two-sample t-tests. The time point for a fixed-time "Booster" in Part 2 will be derived from Part 1 with additional statistical tools such as a broken-stick mixed-effect model.

Discussion

This study aims to further characterize the analgesic effects of OLPs. In doing so, it will provide valuable information needed for later implementation of OLPs in clinical practice, where they could play a role in multimodal analgesic concepts.

Ethics and dissemination

The "Ethikkommission Nordwest- und Zentralschweiz" (BASEC 2023-00296) approved the study protocol. Results of the analysis will be submitted for publication in a peer-reviewed journal.

Clinical Trial Registration

This study is registered at ClinicalTrials.gov (NCT05819476) and is listed in the Swiss National Registry at kofam.ch (SNCTP000005470).

No Magic Pill: A Systematic Review of the Pharmacological Treatments for Compulsive Sexual Behavior Disorder

Compulsive sexual behavior disorder (CSBD) is a burgeoning diagnostic construct. No systematic reviews of CSBD pharmacotherapy interventions have been conducted. We addressed this gap using a three-aim approach. We reviewed researchers' theoretical arguments for various pharmacotherapies, outcomes from pharmacotherapy trials, and the generalizability of the extant findings. Our review included k = 13 studies, with n = 141 participants. An opioid model of reward seeking was the most popular framework, though inconsistently specified. A serotonin model was also documented, though with few details. Naltrexone was the most prominently examined pharmacotherapy and the only medication that reliably demonstrated a therapeutic effect for some (but not all) indicators compared to placebo. Paroxetine and citalopram were also documented in placebo-controlled trials, though their incremental benefit compared to placebo is suspect. Several additional pharmacotherapies have been documented in case series contexts. Across studies, only one female participant was identified. All trials were conducted in developed nations, and race was rarely assessed. We conclude that the case for pharmacotherapy for CSBD is limited and should preferably not occur outside of clinical trial contexts. Naltrexone offers the best evidence for a potential research program, though new theoretically informed approaches are welcome. Finally, we call for additional pharmacotherapy research in women and non-White populations.

Open-label placebo treatment does not enhance cognitive abilities in healthy volunteers

The use of so-called 'smart drugs' such as modafinil to improve cognitive performance has recently attracted considerable attention. However, their side effects have limited user enthusiasm. Open-label placebo (OLP) treatment, i.e., inert treatments that are openly disclosed to individuals as having no active pharmacological ingredient, has been shown to improve various medical symptoms and conditions, including those related to cognitive performance. OLP treatment could therefore be an exciting alternative to pharmacological cognitive enhancers. Here, we used a randomized-controlled design to investigate the effect of a 21-day OLP treatment on several sub-domains of cognitive performance in N = 78 healthy volunteers. Subjective and objective measures of cognitive performance as well as different measures of well-being were obtained before and after the treatment period. Using a combination of classic Frequentist and Bayesian analysis approaches showed no additional benefit from OLP treatment in any of the subjective or objective measures of cognitive performance. Our study thus highlights possible limitations of OLP treatment in boosting cognitive performance in healthy volunteers. These findings are discussed in the light of expectancy-value considerations that may determine OLP efficacy.

The role of positive information provision in open-label placebo effects

Open label placebos (OLPs) appear generally efficacious among clinical samples, but the empirical evidence regarding their use in non-clinical and sub-clinical samples, as well as when administered independent of a convincing rationale, is mixed. Healthy participants (N = 102) were randomised to either a 6-day course of OLP pills with information provision (OLP-plus: N = 35), without information provision (OLP-only: N = 35), or no-treatment control group (N = 32). OLP pills were described as enhancing physical (symptoms and sleep) and psychological (positive and negative emotional) well-being. Well-being was assessed at baseline and on Day 6. Expectancies and adherence were measured. OLP administration interacted with baseline well-being. The OLP-plus group demonstrated increased well-being on all outcomes other than positive emotions, but only when they reported decreased baseline well-being. OLP-only and control groups did not differ. The OLP-plus group demonstrated elevated expectancies, that mediated the OLP effect on physical symptoms relative to control, but only when well-being was lower than average at baseline (i.e. moderated-mediation). Results demonstrate the importance of information provided with OLPs. The moderating effect of baseline outcomes may reconcile inconsistent results regarding clinical and non-clinical samples. Accounting for baseline symptoms in non-clinical and sub-clinical samples is likely to enhance our understanding of when OLPs are effective.

Non-Deceptive Placebos Can Promote Acts of Kindness: A Randomized Controlled Trial

Placebos have often been used to reduce emotional distress but rarely to increase positive feelings. The present study investigated whether a placebo can promote acts of kindness (AoKs) that are associated with emotional well-being. A total of 160 university students were asked to perform an AoK daily for one week. They evaluated their emotional state (feelings of pleasantness, arousal, satisfaction) directly before and after the AoKs. This was monitored via a smartphone app. One group performed each AoK after taking a non-deceptive placebo; the other group received no placebo. Before and after the one-week program, the participants completed three questionnaires that assessed satisfaction with life, positive/negative affect, and flourishing. The participants reported higher pleasantness directly after engaging in an AoK and more satisfaction with life after the program. The motivation to carry out AoKs decreased strongly over the week. However, placebo receivers completed more AoKs than the no-placebo group. The results indicate that placebo treatment can promote the performance of acts of kindness.

The roles of expectation, comparator, administration route, and population in open-label placebo effects: a network meta-analysis

Three meta-analyses have demonstrated the clinical potential of open-label placebos (OLPs). However, there is a need to synthesize the existing evidence through more complex analyses that would make it possible to answer questions beyond mere efficacy. Such analyses would serve to improve the understanding of why and under what circumstances OLPs work (e.g., depending on induced expectations or across different control groups). To answer these questions, we conducted the first network meta-analyses in the field of OLPs. Our analyses revealed that OLPs could be beneficial in comparison to no treatment in nonclinical (12 trials; 1015 participants) and clinical populations (25 trials; 2006 participants). Positive treatment expectations were found to be important for OLPs to work. Also, OLP effects can vary depending on the comparator used. While the kind of administration route had no substantial impact on the OLP effects, effects were found to be larger in clinical populations than in nonclinical populations. These results suggest that the expectation, comparator, administration route, and population should be considered when designing and interpreting OLP studies.

The impact of pharmaceutical form and simulated side effects in an open-label-placebo RCT for improving psychological distress in highly stressed students

Open-label placebo (OLP) may be utilized to reduce psychological distress. Yet, potential contextual effects have not been explored. We investigated the impact of pharmaceutical form and the simulation of side effects in a parallel group RCT (DRKS00030987). A sample of 177 highly stressed university students at risk of depression were randomly assigned by computer generated tables to a 1-week intervention with active or passive OLP nasal spray or passive OLP capsule or a no-treatment control group. After the intervention, groups differed significantly in depressive symptoms but not regarding other outcomes of psychological distress (stress, anxiety, sleep quality, somatization), well-being or treatment expectation. OLP groups benefitted significantly more compared to the no-treatment control group (d = .40), OLP nasal spray groups significantly more than the OLP capsule group (d = .40) and the active OLP group significantly more than the passive OLP groups (d = .42). Interestingly, before intervention, most participants, regardless of group assignment, believed that the OLP capsule would be most beneficial. The effectiveness of OLP treatments seems to be highly influenced by the symptom focus conveyed by the OLP rationale. Moreover, pharmaceutical form and simulation of side effects may modulate efficacy, while explicit treatment expectation seems to play a minor role.

Open-label placebos-a systematic review and meta-analysis of experimental studies with non-clinical samples

The use of open-label placebos (OLPs) has shown to be effective in clinical trials. We conducted a systematic review and meta-analysis to examine whether OLPs are effective in experimental studies with non-clinical populations. We searched five databases on April 15, 2021. We conducted separate analyses for self-reported and objective outcomes and examined whether the level of suggestiveness of the instructions influenced the efficacy of OLPs. Of the 3573 identified records, 20 studies comprising 1201 participants were included, of which 17 studies were eligible for meta-analysis. The studies investigated the effect of OLPs on well-being, pain, stress, arousal, wound healing, sadness, itchiness, test anxiety, and physiological recovery. We found a significant effect of OLPs for self-reported outcomes (k = 13; standardized mean difference (SMD) = 0.43; 95% CI = 0.28, 0.58; I² = 7.2%), but not for objective outcomes (k = 8; SMD =  - 0.02; 95% CI =  - 0.25, 0.21; I² = 43.6%). The level of suggestiveness of the instructions influenced the efficacy of OLPs for objective outcomes (p = 0.02), but not for self-reported outcomes. The risk of bias was moderate for most studies, and the overall quality of the evidence was rated low to very low. In conclusion, OLPs appear to be effective when examined in experimental studies. However, further research is needed to better understand the mechanisms underlying OLPs.

Placebo effects during the waiting period for psychotherapy in patients with depression

Patients with mental health problems typically have to wait for psychological therapies. This study aimed to investigate the effects of a placebo administered to patients with depression while they were waiting for cognitive-behavioral therapy. Sixty-seven patients were randomly assigned to a three-week waiting period with or without treatment with a take-home placebo for daily usage (herbal medicine to mobilize the body’s natural healing powers to be taken orally). Symptoms of depression (self-rated and clinician-rated) were assessed at the beginning and end of the waiting period. Moreover, each week the patients evaluated levels of energy, concentration, relaxation, well-being, and sleep quality. The placebo group showed a greater reduction in symptoms of depression (self-rated and clinician-rated) compared to the standard group. Moreover, placebo treatment was associated with improved overall well-being during the waiting period. In conclusion, placebo treatment can make the wait time for psychotherapy more tolerable for patients with depression.

Clinical trial registration: German Clinical Trials Register (DRKS00028118)

Open-Label Placebo Effects on Psychological and Physical Well-Being: A Conceptual Replication Study

Background

Contrary to traditional placebos, open-label placebos (OLP) abstain from deception, i.e., participants are openly informed to receive an inert substance. Studies in clinical and healthy samples evidence the efficacy of OLPs. This study aims to conceptually replicate and expand findings of a recent OLP study in healthy participants while implementing a within-subject design and daily instead of retrospective assessments. Additionally, the effect of a brand name on the medicine container is tested and possible predictors of the OLP effects are explored.

Method

Healthy participants (N = 75) received OLP and no placebo for 5 days each (randomized sequence) and answered daily questionnaires on sleep quality, bodily symptoms, mental well-being, and psychological distress. The medicine container of half the participants had a brand name, the remaining did not. Different personality traits and situational factors were assessed.

Results

Mental and physical well-being did not differ between OLP and control phase, i.e., overall, no OLP effect emerged. Contrast analysis indicated that an OLP effect emerged for sleep quality and psychological distress when no brand name was present. Further, an OLP effect emerged in persons with higher expectations for bodily symptoms (r = .23, p = .046) and psychological distress (r = .24, p = .037).

Conclusions

Methodological differences to the original study are discussed as an explanation for the failure to induce overall OLP effects. Future studies should continue to replicate previous findings and determine the exact conditions of successful implementation of OLP effects in healthy as well as clinical samples.

Deceptive and open-label placebo effects in experimentally induced guilt: a randomized controlled trial in healthy subjects

Placebos are known to yield significant effects in many conditions. We examined deceptive and open-label placebo effects on guilt, which is important for self-regulation and a symptom of mental disorders. Following an experimental induction of guilt, healthy subjects were randomized to deceptive placebo (DP; n = 35), open-label placebo (OLP; n = 35), or no treatment (NT; n = 39). The primary outcome was guilt responses assessed in area under the curve (AUC). Secondary outcomes were shame, guilt, and affect. We hypothesized that DP and OLP would reduce guilt compared to NT. Guilt responses were higher in the NT group than in the placebo groups (estimate = 2.03, 95% CI = 0.24-3.82, d = 0.53), whereas AUC guilt did not differ significantly between the placebo groups (estimate = -0.38, 95% CI = -2.52-1.76, d = -0.09). Placebos are efficacious in reducing acute guilt responses, regardless of the placebo administration (i.e., open vs. deceptive). Furthermore, we observed narrative-specific effects with significant changes of guilt but not shame, pride, or affect. These results indicate not only that guilt is amenable to placebos but also that placebos can be administered in an ethical and potentially emotion-specific manner.

Placebo: a brief updated review

Our aims were to provide updated information on placebo/nocebo effect and the potential use of placebo in clinical practice. This article can only provide a rough overview on the placebo and nocebo effect and is intended to serve as a starting point for the reader to go deeper into the corresponding literature. The placebo effect has been observed in multiple medical conditions, after oral administration, with manual therapies as well as with surgery and invasive procedures. The use of placebo in clinical trials is fundamental, although the ethics of its use is under discussion. The placebo may behave like a drug from the pharmacokinetic and pharmacodynamic point of view and can also be associated with adverse events (nocebo effect). Placebo can modify treatment by increasing or decreasing the effects of drugs. The factors associated with the occurrence of placebo effect are multiple, but in addition to those that depend on the placebo itself, the doctor-patient relationship would be the most important. As a result of findings that were published in the last two decades, the psycho-neurobiological basis of placebo is becoming better understood, although further studies are needed. In conclusion, the placebo effect in the clinic exhibits weak to moderate intensity. Placebo, in addition to its use in the clinical trial, should be considered another therapeutic remedy either as stand alone or in association with treatment, and could be useful in certain circumstances. The use of placebo should be regulated by the European health authorities through a guide in clinical practice that will improve patient care.

No open-label placebo effect in insomnia? Lessons learned from an experimental trial

BACKGROUND

Open-label placebo (OLP) treatment seems to be effective in several medical conditions but has not yet been investigated in insomnia. Furthermore, it needs to be evaluated whether providing a plausible treatment rationale is essential to obtain OLP effects.

METHODS

In two consecutive nights, the sleep of patients with primary insomnia (n = 45) was assessed via subjective and objective measures. Before the second night, they received a single OLP pill that was randomly provided either with a treatment rationale (OLP+) or without (OLP-). When (M)ANOVAs did not reveal differential effects between the two OLP groups, the OLP+ group was compared post-hoc to a formerly assessed no pill control sample (NPC; n = 23).

RESULTS

Neither the MANOVAs nor the ANOVAs revealed significant interaction effects of treatment group and assessment night. The OLP+ condition was superior neither to OLP- nor to NPC in improving the patients' sleep.

DISCUSSION

Our findings do neither confirm the general efficacy of OLP in primary insomnia nor differential effects depending on the treatment rationale. Possible explanations lie in the dosing scheme (i.e., single OLP application), the provision of the OLP rationale by video and the experimental instead of therapeutic character of our investigation. Trials with larger samples and longer-term OLP treatment in insomnia are needed. Providing the rationale face-to-face and in a clinical setting might be additionally beneficial.

Associations Between Interindividual Differences, Expectations and Placebo and Nocebo Effects in Itch

Introduction: Placebo and nocebo effects are positive and negative health outcomes that can be elicited by the psychosocial context. They can be mediated by expectations, and may emerge in somatic symptoms even when people are aware of these effects. Interindividual differences (e.g., in personality, affective states) could impact placebo and nocebo responding, but findings are inconsistent. Methods: The current work examined expectation as a mediator of the association between verbal placebo and nocebo suggestions (VSs) and histamine-induced itch across three experimental studies. Moreover, we examined whether interindividual differences (e.g., in optimism, neuroticism, behavioral activation system (BAS), body ignorance) modulated: (1) the direct association between VSs and itch (direct moderation), and (2) the indirect, expectation-mediated association between VSs and itch (moderated mediation). Positive VSs were compared to neutral instructions (Study 1; n = 92) or negative VSs (Studies 2+3; n = 203) in an open-label (i.e., explaining placebo and nocebo effects) or closed-label (concealed) context using PROCESS. First, mediation of VSs effects on itch by expectations was tested. Next, moderation by individual traits was explored using conditional process analyses. Results: The effects of VSs on itch were significantly mediated by expectation in Study 1 and in the open-label (but not closed-label) contexts of Studies 2 and 3. Ignorance of bodily signals marginally moderated the direct effects of VSs on itch when closed-label suggestions were given: at low levels of body ignorance, effects of positive and negative VSs were stronger. Moreover, moderated mediation was observed in the open-label groups of Studies 2 and 3: The expectation-mediated effects of VSs on itch were stronger when BAS drive was lower. Conclusion: Overall, the effects of VSs on itch were mediated by expectations in the open-label, but not the closed-label context. Moreover, the current work suggests that placebo and nocebo effects may be moderated by ignorance of bodily signals and the BAS. There was limited evidence that other interindividual differences modulated placebo and nocebo responding in itch.

Open-Label Placebo Treatment for Acute Postoperative Pain (OLP-POP Study): Study Protocol of a Randomized Controlled Trial

Introduction: Open-label placebos have been proposed as way of using long recognized analgesic placebo effects in an ethical manner. Recent evidence shows efficacy of open-label placebos for clinical conditions, but there is need for more research on open-label placebos in acute pain. In the treatment of acute postoperative pain, minimization of opioid related side effects remains one of the key challenges. Therefore, this study aims at investigating the potential of adding unconditioned open-label placebos to treatment as usual as a means of reducing opioid consumption and its related side effects in patients with acute postoperative pain. Methods and Analysis: This is the protocol of an ongoing single site randomized controlled trial. The first patient was enrolled in May 2020. In total, 70 patients suffering from acute postoperative pain following dorsal lumbar interbody fusion are randomized to either a treatment as usual group or an experimental intervention group. The treatment as usual group consists of participants receiving a patient-controlled morphine pump. On day 1 and 2 post-surgery, patients in the intervention group receive, in addition to treatment as usual, two open-label placebo injections per day along with an evidence-based treatment rationale explaining the mechanisms of placebos. The primary outcome is measured by means of self-administered morphine during day 1 and 2 post-surgery. Several other outcome measures including pain intensity and adverse events as well as potential predictors of placebo response are assessed. Analysis of covariance will be used to answer the primary research question and additional statistical techniques such as generalized linear mixed models will be applied to model the temporal course of morphine consumption. Discussion: This study will provide valuable insights into the efficacy of open-label placebos in acute pain and will potentially constitute an important step toward the implementation of open-label placebos in the clinical management of acute postoperative pain. In addition, it will shed light on a cost-efficient and patient-centered strategy to reduce opioid consumption and its related side effects, without any loss in pain management efficacy. Ethics and Dissemination: The "Ethikkommission Nordwest- und Zentralschweiz" (BASEC2020-00099) approved the study protocol. Results of the analysis will be submitted for publication in a peer-reviewed journal. Clinical Trial Registration: The study is registered at ClinicalTrials.gov (NCT04339023) and is listed in the Swiss national registry at kofam.ch (SNCTP000003720).

Lay perspectives of the open-label placebo rationale: a qualitative study of participants in an experimental trial

OBJECTIVES

To analyse participants' concepts about the open-label placebo (OLP) effect; to explore their views about the discussion points that are applied in conventional OLP trials and to examine their experiences of taking part in an OLP trial.

DESIGN

A qualitative study using thematic analysis of semistructured interviews that were nested within a randomised controlled trial investigating experimental OLP analgesia (registered at ClinicalTrials.gov: NCT02578420).

PARTICIPANTS

30 healthy adults who took part in the randomised controlled trial.

RESULTS

Participants mostly conceptualised placebo as something that is inert and requires deception in order to be effective. Interviewees used a broad definition of placebos, going beyond a conventional notion of sugar pills. In contrast to the conventional OLP rationale, participants seldom emphasised classical conditioning as a mechanism of placebo effects, stressing a variety of other well-established components through which placebos might be therapeutic, whereas the conventional OLP disclosures state that 'a positive attitude helps but is not necessary', participants in our study applied other attitudes, such as 'it's worth a try'. When asked about their experiences during the trial, the majority emphasised that the concept of OLP was completely novel to them. Participants were rather sceptical about the efficacy of the intervention.

CONCLUSION

Integrating lay perspectives into the scientific rationale of OLP treatments might enhance the plausibility and credibility of the rationale in ethical treatments.

TRIAL REGISTRATION NUMBER

NCT02578420.

Open-label placebo treatment to improve relaxation training effects in healthy psychology students: a randomized controlled trial

Placebos, that are administered with deception, can reduce stress and increase relaxation. The present study investigated an open-label placebo (OLP) to improve the effects of Progressive Muscle Relaxation (PMR) training. A total of 160 psychology students were randomly assigned to a 14-day PMR course with or without daily OLP treatment. The placebo was administered along with an explanation of placebo effects and the verbal suggestion that the OLP activates the body’s natural relaxation response. The relaxation instructions for home practice were delivered via a smartphone app, which was also used for the evaluation of the exercises. The participants of the OLP group completed more PMR exercises (M = 9.75) than the group without a placebo (M = 8.15). The two groups did not differ in reported exercise-related changes in relaxation level. On average, the OLP group rated the effects of the placebo as very low and was characterized by a higher drop-out rate compared to the group without OLP. Some participants experienced the OLP as negative. In conclusion, factors that influence the acceptance of OLP treatment require further investigation.

Open- and Closed-Label Placebo and Nocebo Suggestions About a Sham Transdermal Patch

OBJECTIVE

Placebo effects may occur when it is known that an inert substance is given (i.e., open-label placebo). It is not yet clear whether these effects are similar to concealed (i.e., closed-label) placebo effects for itch or whether nocebo effects can be induced under open-label conditions.

METHODS

Healthy volunteers (n = 112) were randomized to an open-label (I) or closed-label (II) positive suggestions group, or an open-label (III) or closed-label (IV) negative suggestions group. Participants were told, as cover story, that a transdermal caffeine patch would be applied that positively influences cognitive abilities and, as a side effect, positively or negatively (depending on group allocation) influences itch. Participants in the open-label groups were given a rationale explaining placebo and nocebo effect mechanisms. Itch (the primary outcome) was induced at baseline and postsuggestions by histamine iontophoresis.

RESULTS

Analyses of variance revealed significantly lower itch in the positive compared with the negative suggestions groups for both open- and closed-label contexts (all, p ≤ .008, Cohen d ≥ 0.47). Self-rated skin response was less severe after positive versus negative suggestions (all, p ≤ .017, Cohen d ≥ 0.33), but no effects on physical skin response were found (all, p ≥ .23, Cohen d ≤ 0.30).

CONCLUSIONS

Itch can be reduced by positive compared with negative suggestions under both open- and closed-label conditions. These findings indicate that open-label suggestions may potentially be a tool to use placebo effects for self-reported outcomes in clinical practice, for example, by explaining the role of expectancy in treatment. It needs to be investigated further under which circumstances an open-label rationale may impact placebo and nocebo effects.Trial Registration:www.trialregister.nl; NTR7174.

Placebos without deception reduce self-report and neural measures of emotional distress

Several recent studies suggest that placebos administered without deception (i.e., non-deceptive placebos) can help people manage a variety of highly distressing clinical disorders and nonclinical impairments. However, whether non-deceptive placebos represent genuine psychobiological effects is unknown. Here we address this issue by demonstrating across two experiments that during a highly arousing negative picture viewing task, non-deceptive placebos reduce both a self-report and neural measure of emotional distress, the late positive potential. These results show that non-deceptive placebo effects are not merely a product of response bias. Additionally, they provide insight into the neural time course of non-deceptive placebo effects on emotional distress and the psychological mechanisms that explain how they function.

There is controversy about whether placebos without deception cause real psychobiological benefits. Here, the authors show that the positive effects of placebos without deception are more than response bias by providing evidence they can reduce self-report and neural measures of emotional distress.

[Appearances are not deceptive: clinical evidence and new research approaches to open-label placebo]

The efficacy of placebo effects is proven in experimental, clinical and meta-analytical studies. However, harnessing placebo effects in clinical treatment contexts is hampered legally and ethically, since it has been considered necessary to conceal the inert nature of a placebo application. Interestingly, the results of recently published small, randomized trials suggest that patients can experience symptom relief after taking pills that they know lack any medication. In particular, these so-called open-label placebos (OLP) improved strongly fluctuating and individually distressing complaints such as gastrointestinal, neurological, psychosomatic and pain symptoms. Although the mechanisms are largely unknown, the open-label placebo application might be a promising way of fostering placebo effects in clinical settings. Initial study protocols already provide schedules for OLP use as an additional treatment in opioid use disorders. Likewise, the reduction of side effects, conversion effects or withdrawal symptoms through OLP applications in pharmacologically active treatments appear to serve as appropriate therapy goals. Further mechanistic studies are urgently needed to investigate the thus far only hypothetically proposed underlying mechanisms of OLP.

Deceptive but not open label placebos attenuate motion-induced nausea

OBJECTIVE

Nausea is a common complaint, known to respond to the placebo effect. Existing research has employed deception when administering placebos for nausea, limiting therapeutic translation on ethical grounds. We therefore examined the potential of non-deceptive open-label placebos (OLPs) to reduce nausea.

METHODS

Galvanic Vestibular Stimulation (GVS) and Virtual Reality (VR) were employed to model nausea in healthy volunteers across two experiments. In both experiments nausea was elicited with and without sham treatment (peppermint vapor and brain stimulation, respectively). In Exp. 1, participants (n = 61) were randomized to deceptive placebo, semi-open placebo, fully-open placebo, or control. In Exp. 2, participants (n = 93) were randomized to deceptive placebo, semi-open placebo, or control.

RESULTS

Exp. 1 found limited evidence for a placebo effect (F(1, 56) = 1.15, p = .29, η_p² =0.02), even following deceptive treatment (F(1, 56) = 1.92, p = .17, η_p²=0.03). In Exp. 2, deceptive placebo reduced nausea relative to control (F(1, 89) = 6.91, p = .010, η_p²=0.07) and OLP (F(1, 89) = 5.47, p = .022, η_p²=0.06). Pooled Bayesian analysis across experiments provided strong evidence that deceptive placebos reduce nausea relative to control (BF₁₀ = 30.91) and anecdotal evidence for the benefit of deceptive treatment over non-deceptive (BF₁₀ = 2.46) and no benefit of OLP over control (BF₁₀ = 0.63).

CONCLUSIONS

No positive evidence for OLP effects in nausea were observed. However, a deceptive effect in VR was observed. These findings raise questions regarding the efficacy of open-label intervention in nausea.

The Bell Tolls for Homeopathy: Time for Change in the Training and Practice of North American Naturopathic Physicians

North American naturopathic medicine is a distinct form of practice that is woven into the larger fabric of integrative medicine; in a number of US states and Canadian provinces, naturopathic doctors enjoy a wide scope of practice, including the ability to make diagnoses, order tests, use medical technology, write prescription drugs, and perform minor surgeries. However, the basic premise of naturopathic medicine and its guiding principles-considering the whole person and supporting healthy lifestyle behaviors-is the unifying approach in clinical practice. In the 1970s, homeopathy-considered in many circles to be a hypothesis-driven, fringe form of alternative medicine-became embedded into the training and practice of North American naturopathic doctors. Since the earliest days of its theory (circa 1800), homeopathy has escaped, and continues to escape, biological plausibility; however, the persistence of this modality (and the insistence by both its consumers and practitioners that it provides benefit) speaks to the role of expectations, beliefs, values, agency, context effects, and the placebo-at-large. It is our contention that the progression of professional naturopathic medicine in the 21st century requires a major transition in how it approaches the subject of homeopathy. We propose that students should be encouraged to critically analyze the tenets of homeopathy, its lesser known history, and the idea of homeopathy as a biomedicine that simply awaits untold chemicophysical mechanisms. Furthermore, the modality of homeopathy should be incorporated into the larger context of placebo studies, narrative medicine, ethics, and psychotherapeutic techniques.

Positive effects of acupressure bands combined with relaxation music/instructions on patients most at risk for chemotherapy-induced nausea

PURPOSE

Research by our group has shown that acupressure bands are efficacious in reducing chemotherapy-induced nausea (CIN) for breast cancer patients who expect nausea, and that their effectiveness in controlling CIN can largely be accounted for by patients' expectations of efficacy, i.e., a placebo effect. The present research examined if the effectiveness of acupressure bands could be enhanced by boosting patients' expectation of the bands' efficacy.

METHODS

Two hundred forty-two chemotherapy-naïve patients with breast cancer who expected nausea were randomized. Arms 1 and 2 received acupressure bands, plus a relaxation MP3 and written handout that were either expectancy-enhancing (arm 1) or expectancy-neutral (arm 2). Arm 3 was the control without bands or MP3 and received standard care. All participants received guideline-specified antiemetics.

RESULTS

Peak CIN for arms 1, 2, and 3 on a 1-7 scale was 3.52, 3.55, and 3.87, respectively (p = 0.46). Because no differences were observed between arms 1 and 2 (primary analysis), we combined these two arms (intervention) and compared them to controls for the following analyses. A significant interaction was found between intervention/control and receiving doxorubicin-based chemotherapy (yes/no) and pre-treatment anxiety (high/low). Intervention patients receiving doxorubicin had lower peak CIN than controls (3.62 vs. 4.38; p = 0.02). Similarly, intervention patients with high pre-treatment anxiety had a lower peak CIN than controls (3.62 vs. 4.62; p = 0.01).

CONCLUSIONS

In breast cancer patients undergoing chemotherapy and having high CIN expectation, acupressure bands combined with a relaxation recording were effective in reducing CIN for patients who received doxorubicin or had high anxiety.