Providing open-label placebos remotely-A randomized controlled trial in allergic rhinitis

The effect of open-label placebo on allergic rhinitis symptoms: A systematic review and meta-analysis of randomized controlled trials

KEY POINTS

The evidence regarding the open-label placebo effect on allergic rhinitis symptoms remains uncertain. Open-label placebo significantly reduced the frequency of symptoms in allergic rhinitis patients with similar safety profiles; however, there was no effect on the severity of symptoms and impairment due to symptoms. The statistically significant impact on symptom frequency can be considered not clinically significant.

Placebo and the law of identification

Thousands of essays and studies have been published on placebo and nocebo. Yet, despite this plethora of information, we are not much closer to a comprehensive understanding of the fundamental mechanism producing placebo and nocebo effects than we were in 1946, when participants in the Cornell Conferences on Therapy speculated on the roles of authority, belief and expectancy. In this paper, we examine the weaknesses in current placebo and nocebo definitions and theories. We also propose a more concise and comprehensive definition and theory of placebo and nocebo by introducing the Law of Identification and the Generic Placebo Instruction (GPI). The latter being the placebo/nocebo information expressed or implied in virtually every clinical encounter and trial; the former (i.e., the Law of Identification), being what drives the GPI to actualization. Further, we demonstrate the explanatory power of this new theory and suggest clinical studies that test predictions arising from it - studies whose results, if positive, would translate universally into clinical practice.

Remotely administered non-deceptive placebos reduce COVID-related stress, anxiety, and depression

Research suggests that placebos administered without deception (i.e. non-deceptive placebos) may provide an effective and low-effort intervention to manage stress and improve mental health. However, whether non-deceptive placebos administered remotely online can manage distress for people at risk for developing high levels of affective symptoms remains unclear. Volunteers experiencing prolonged stress from the COVID-19 pandemic were recruited into a randomized controlled trial to examine the efficacy of a non-deceptive placebo intervention administered remotely online on affective outcomes. COVID-related stress, overall stress, anxiety, and depression were assessed at baseline, midpoint, and endpoint. Compared with the control group, participants in the non-deceptive placebo group reported significant reductions from baseline in all primary affective outcomes after 2 weeks. Additionally, participants in the non-deceptive placebo group found the intervention feasible, acceptable, and appropriate for the context. Non-deceptive placebos, even when administered remotely online, offer an alternative and effective way to help people manage prolonged stress. Future large-scale studies are needed to determine if non-deceptive placebos can be effective across different prolonged stress situations and for clinical populations.

Open-label placebos enhance test performance and reduce anxiety in learner drivers: a randomized controlled trial

Passing the driving school test can be very challenging, especially in big cities, where up to 52% of all students fail this test. Consequently, many learner drivers experience stress and anxiety. For some learner drivers these feelings can be extreme and negatively affect the performance in the driving test. Different strategies to face anxiety and stress are known, including, for example, psychological or pharmacological approaches and even placebo pills. Recent intriguing findings have also demonstrated that placebos without deception, so-called open-label placebos, successfully reduce anxiety. Here we aimed to test effects of this novel treatment for learner drivers. We investigated whether open-label placebos affect test performance and feelings of anxiety in learner drivers. Sixty-eight healthy participants (mean age 21.94 years, 26 females) were randomized into two groups. The open-label placebo group received placebo pills two weeks before the driving test (two pills each day). The control group received no treatment. Results revealed that the open-label placebo group experienced significantly less anxiety than the control group before the test (measured with the State-Trait-Anxiety-Inventory, STAI-S, and the German Test Anxiety Inventory, PAF). Moreover, in the open-label placebo group less learner drivers failed the driving test (29.41% vs. 52.95%). The results suggest that open-label placebos may provide an ethical unproblematic way to experience less anxiety and might also enhance the probability to pass the driving test. We discuss possible mechanisms of open-label placebos and limitations of our findings.

Development and Psychometric Evaluation of the Hope in Medicine Scale

Background

Hope is an integral, multi-dimensional part of seeking medical treatment. The aim of this study was to develop a self-report scale, the Hope in Medicine (HIM) scale, to measure different modes of hoping in relation to the course of symptoms, the effects of treatment, and supporting medical research.

Method

We examined the psychometric properties of the scale in a sample of 74 allergic rhinitis patients participating in a 2-week randomized-controlled trial comparing open-label placebos (OLP) with treatment as usual (TAU).

Results

The HIM scale had a Cronbach's α of .78. An exploratory factor analysis revealed four factors: realistic hope (i.e., hoping for specific positive outcomes such as improvement in symptoms), transcendent hope (i.e., non-directed hoping that things will turn out positively), utopian hope (i.e., hoping to contribute to greater knowledge), and technoscience hope (i.e., hoping for scientific breakthroughs). Speaking to the convergent validity of the scale, realistic hope was moderately related to treatment expectancies (r = .54); transcendent hope was related to optimism (r = .50), treatment expectancies (r = .37), self-efficacy (r = .36), and inversely correlated with pessimism (r = -.43). Hope subscales predicted neither course of symptoms nor impairment.

Conclusion

The HIM scale is a questionnaire with adequate internal consistency allowing to assess four modes of hoping. Preliminary results for its convergent validity are promising. Yet, further validation is needed.

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.

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.

A randomized controlled trial of effects of open-label placebo compared to double-blind placebo and treatment-as-usual on symptoms of allergic rhinitis

Placebo effects are known for numerous clinical symptoms. Until recently, deception of placebos was thought to be essential for placebo effects, but intriguing new studies suggest that even placebos without concealment (open-label placebos) may help patients with various clinical disorders. Most of those studies compared open-label placebo treatments with no treatment conditions (or treatment "as usual"). Given that open-label placebo studies obviously cannot be blinded, additional control studies are important to assess the efficacy of open-label placebos. The current study aimed to fil this gap by comparing open-label with conventional double-blind placebos and treatment as usual. Patients with seasonal allergic rhinitis were randomly divided in different groups. The first group received open-label placebos, the second double-blind placebos, and the third was treated as usual. After 4 weeks, results demonstrated that open-label placebos improved allergic symptoms more than treatment-as-usual and even more as double-blind placebos. In addition, we observed that allergic symptoms in general (and also the open-label placebo effects) were reduced by the Covid-19 pandemic. The results suggest that seasonal allergic symptoms may be relieved by open-label placebos. We discuss these results by addressing possible different mechanisms of open-label and conventionally concealed placebo treatments.

Imaginary pills and open-label placebos can reduce test anxiety by means of placebo mechanisms

Placebos have been shown to be beneficial for various conditions even if administered with full transparency. Hence, so-called open-label placebos (OLPs) offer a new way to harness placebo effects ethically. To take this concept one step further, this study aimed at evaluating placebo effects without the use of a physical placebo, i.e., by imagining taking a pill. Healthy students (N = 173) with self-reported test anxiety were either randomized to an imaginary pill (IP; n = 55), an OLP (n = 59) or a control group (CG; n = 59). Both intervention groups were instructed to take two pills daily for three weeks. Primary outcome was test anxiety, secondary outcomes were sleep quality, general well-being and test performance. Groups test anxiety differed at study-endpoint, F(2,169) = 11.50, p < .001. Test anxiety was lower in the intervention groups compared to the CG, t(169) = - 4.44, p < .001, d = - 0.71. The interventions did not differ significantly, i.e., both were similarly efficacious, t(169) = 0.61, p = .540, d = 0.11. The interaction between group and time in explaining test anxiety was significant, F(5,407.93) = 6.13, p < .001. OLPs and IPs reduced test anxiety in healthy participants compared to the CG. This finding opens the door for a novel and ethical method to harness placebo effects.

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.

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.

Correction: Providing open-label placebos remotely-A randomized controlled trial in allergic rhinitis

[This corrects the article DOI: 10.1371/journal.pone.0248367.].