Effects of placebos without deception compared with no treatment: protocol for a systematic review and meta-analysis

Assessing the impact of the Royal Canadian Mounted Police (RCMP) protocol and Emotional Resilience Skills Training (ERST) among diverse public safety personnel

BACKGROUND

Public safety personnel (PSP; e.g., border services personnel, correctional workers, firefighters, paramedics, police, public safety communicators) are frequently exposed to potentially psychologically traumatic events. Such events contribute to substantial and growing challenges from posttraumatic stress injuries (PTSIs), including but not limited to posttraumatic stress disorder.

METHODS

The current protocol paper describes the PSP PTSI Study (i.e., design, measures, materials, hypotheses, planned analyses, expected implications, and limitations), which was originally designed to evaluate an evidence-informed, proactive system of mental health assessment and training among Royal Canadian Mounted Police for delivery among diverse PSP (i.e., firefighters, municipal police, paramedics, public safety communicators). Specifically, the PSP PTSI Study will: (1) adapt, implement, and assess the impact of a system for ongoing (i.e., annual, monthly, daily) evidence-based assessments; (2) evaluate associations between demographic variables and PTSI; (3) longitudinally assess individual differences associated with PTSI; and, (4) assess the impact of providing diverse PSP with a tailored version of the Emotional Resilience Skills Training originally developed for the Royal Canadian Mounted Police in mitigating PTSIs based on the Unified Protocol for the Transdiagnostic Treatment of Emotional Disorders. Participants are assessed pre- and post-training, and then at a follow-up 1-year after training. The assessments include clinical interviews, self-report surveys including brief daily and monthly assessments, and daily biometric data. The current protocol paper also describes participant recruitment and developments to date.

DISCUSSION

The PSP PTSI Study is an opportunity to implement, test, and improve a set of evidence-based tools and training as part of an evidence-informed solution to protect PSP mental health. The current protocol paper provides details to inform and support translation of the PSP PTSI Study results as well as informing and supporting replication efforts by other researchers.

TRIAL REGISTRATION

Hypotheses Registration: aspredicted.org, #90136. Registered 7 March 2022-Prospectively registered.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05530642. Registered 1 September 2022-Retrospectively registered. The subsequent PSP PTSI Study results are expected to benefit the mental health of all participants and, ultimately, all PSP.

The Royal Canadian Mounted Police (RCMP) Study: protocol for a prospective investigation of mental health risk and resilience factors

The Royal Canadian Mounted Police (RCMP), like all public safety personnel (PSP), are frequently exposed to potentially psychologically traumatic events that contribute to posttraumatic stress injuries (PTSI). Addressing PTSI is impeded by the limited available research. In this protocol paper, we describe the RCMP Study, part of the concerted efforts by the RCMP to reduce PTSI by improving access to evidence-based assessments, treatments and training as well as participant recruitment and RCMP Study developments to date. The RCMP Study has been designed to (1) develop, deploy and assess the impact of a system for ongoing annual, monthly and daily evidence-based assessments; (2) evaluate associations between demographic variables and PTSI; (3) longitudinally assess individual differences associated with PTSI; (4) augment the RCMP Cadet Training Program with skills to proactively mitigate PTSI; and (5) assess the impact of the augmented training condition (ATC) versus the standard training condition (STC). Participants in the STC (n = 480) and ATC (n = 480) are assessed before and after training and annually for 5 years on their deployment date; they also complete brief monthly and daily surveys. The RCMP Study results are expected to benefit the mental health of all participants, RCMP and PSP by reducing PTSI among all who serve.

Open-Label Placebo Interventions With Drinking Water and Their Influence on Perceived Physical and Mental Well-Being

In recent years, the postulation that deception is necessary for placebos to have an effect on pain relief or increased well-being has come into question. Latest studies have shown that an openly administered mock drug works just as well as a deceptively administered placebo on certain complaints. This open-label placebo effect has primarily been used in the area of pain treatment so far. This study is the first to examine the effect of such placebos on healthy individuals with the use of drinking water. In two experiments, participants were required to use certain specified water bottles for their daily drinking water consumption. At the beginning of Experiment 1, all participants (N = 68) received one bottle of water, which they were asked to refill themselves each day during a 2-week intervention period. In Experiment 2, participants (N = 75) received a new sealed water bottle every day. In both experiments, participants were randomly assigned to one of four groups: no treatment (control group CG), open-label placebo without rationale (OPR^–), open-label placebo with rationale (OPR⁺), and open-label placebo with additional rationale in a suggested relaxed state (group OPR⁺⁺). We conducted baseline and post-treatment measurements of the subjective perceived physical and mental well-being of the participants. In Experiment 1, only the OPR⁺⁺ group reported enhanced vitality at the post-treatment level compared to the other groups. In Experiment 2, post-treatment measurements showed improvements for the OPR⁺⁺ group in the Physical Performance Capability, Mental Performance Capability, Emotional Balance, Overall Recovery, Negative Emotional State, and Overall Stress categories compared to the other groups. Our results support the idea that placebos with an additional rationale in a suggestive relaxed state are more effective than with just a rationale in a normal state. Furthermore, our study shows the tendency that OLP⁺⁺ in the form of water with health claims may be more effective when the water is given in several sealed bottles separately than in one sealed but refillable bottle.

Placebos as a Source of Agency: Evidence and Implications

Bioethical discussions surrounding the use of placebos in clinical practice have long revolved around the moral permissibility of deceiving a patient if it is likely to benefit them. While these discussions have been insightful and productive, they reinforce the notion that placebo effects can only be induced through deception. This paper challenges this notion, looking beyond the paradigmatic clinical encounter involving deceptive placebos and towards many other routes that bring about placebo effects. After briefly describing the bioethical terrain surrounding the deceptive use of placebos in clinical practice, section 1 offers an examination of the various mechanisms known to contribute to placebo effects: classical conditioning, expectations, affective pathways, open-label placebo treatments, and additional factors that do not fall easily into a single category. The following section explores how each of these routes can be harnessed to bring about clinical benefits without the use of deception. This provides grounding for reconceiving of the placebo effect as a clinical tool that is not always in conflict with patient autonomy and can even be seen as a source of agency. In the final section, implications of the shift away from seeing placebos as necessarily deceptive are discussed. These include the necessity of looking beyond the clinical encounter and mainstream medicine as the primary sites of placebo responses, how important acknowledging the limits of placebo effects will be when we do so, as well as the difficulties of disentangling agency, responsibility, and blame within medicine.

Is the rationale more important than deception? A randomized controlled trial of open-label placebo analgesia

Research on open-label placebos questions whether deception is a necessary characteristic of placebo effects. Yet, comparisons between open-label and deceptive placebos (DPs) are lacking. We therefore assessed effects of open-label placebos and DPs in comparison with no treatment (NT) with a standardized experimental heat pain paradigm in a randomized controlled trial in healthy participants. Participants (N = 160) were randomly assigned to NT, open-label placebo without rationale (OPR-), open-label placebo with rationale (OPR), and DP. We conducted baseline and posttreatment measurements of heat pain threshold and tolerance. Apart from the NT, all groups received an application of a placebo cream. Primary outcomes were planned comparisons of heat pain tolerance and the corresponding intensity and unpleasantness ratings. Objective posttreatment pain tolerance did not differ among groups. However, for subjective heat pain ratings at the posttreatment tolerance level, groups with a rationale (OPR and DP) reported diminished heat pain intensity (t(146) = -2.15, P = 0.033, d = 0.43) and unpleasantness ratings (t(146) = -2.43, P = 0.016, d = 0.49) compared with the OPR-group. Interestingly, the OPR and the DP groups did not significantly differ in heat pain intensity (t(146) = -1.10, P = 0.272) or unpleasantness ratings (t(146) = -0.05, P = 0.961) at the posttreatment tolerance level. Our findings reveal that placebos with a plausible rationale are more effective than without a rationale. Even more, open-label placebos did not significantly differ in their effects from DPs. Therefore, we question the ubiquitously assumed necessity of concealment in placebo administration.

Increasing effort without noticing: A randomized controlled pilot study about the ergogenic placebo effect in endurance athletes and the role of supplement salience

Purpose

Previous research shows that endurance performance can be enhanced by placebo ergogenic aids. This study investigates the ergogenic placebo response, which we define as an increase in objective and physiological effort without an increase in subjective effort, in competitive cyclists. The primary objective of this study is to explore the role of supplement salience in the ergogenic placebo response, while the secondary aim is to assess whether believing to have taken an inactive placebo supplement attenuates the desired ergogenic effect.

Methods

We employed a double-blind placebo-controlled study design and compared a high salience (pudding) to a low salience (capsules) ergogenic placebo supplement and to a no treatment control group. Thirty-four male athletes (30.0 ± 5.7 years) performed two self-regulated time trials on an isokinetic cycling ergometer, one without intervention serving as a baseline and one with intervention according to group assignment. At both time trials, power output (objective effort), blood lactate (physiological effort) and the rating of perceived exertion (subjective effort) were measured.

Results

Receiving a high salience supplement can increase physiological and objective effort without a proportional rise in subjective effort, suggesting a decoupling of perceived exertion and endurance performance. Low salience and control group both showed no such ergogenic placebo response. Athletes’ belief concerning the true nature of the ergogenic aid (inactive placebo vs. ergogenic supplement) did not influence the ergogenic placebo response.

Conclusion

High salience placebo ergogenic aids can elicit enhanced performance without the athlete noticing (exertion), and deception of athletes seems unnecessary as even believing to have received an inactive placebo supplement maintains the ergogenic placebo response.

The Influence of Expectation on Nondeceptive Placebo and Nocebo Effects

Nondeceptive placebo has demonstrated its efficiency in clinical practice. Although the underlying mechanisms are still unclear, nondeceptive placebo effect and nondeceptive nocebo effect may be mediated by expectation. To examine the extent to which expectation influences these effects, the present study compared nondeceptive placebo and nocebo effects with different expectation levels. Seventy-two healthy female participants underwent a standard conditioning procedure to establish placebo and nocebo effects. Sequentially, participants were randomized to one of the four experimental groups—baseline (BL), no expectation intervention (NoEI), expectation increasing (EI), and expectation decreasing (ED) groups, to receive either no intervention or interventions through different verbal suggestions that modulated their expectation. Placebo and nocebo effects were established in all four groups after the conditioning phase. However, after disclosing the placebo and nocebo, the analgesic and the hyperalgesic effects only persisted in the EI group, when compared with the BL group. Our results provide evidence highlighting the critical role of increased expectation in nondeceptive placebo and nocebo effects. The finding suggests that open-label placebo or nocebo per se might be insufficient to induce strong analgesic or hyperalgesic response and sheds insights into administrating open-label placebo and avoiding open-label nocebo in clinical practice.

Effects of placebos without deception compared with no treatment: A systematic review and meta-analysis

OBJECTIVE

To investigate the clinical efficacy of open-label placebos compared with no treatment in a systematic review and meta-analysis.

METHODS

We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations (OvidSP), EMBASE (OvidSP), and clinical trials registers and screened reference lists. The search was run on 27^th April 2015. We included all randomized controlled trials of any medical condition with open-label placebo and no-treatment groups. Authors independently assessed records and extracted data. We excluded nonrandomized trials and nonclinical studies. Risk of bias was assessed using Cochrane criteria. We used random-effects model for meta-analysis.

RESULTS

We screened 348 publications, assessed 24 articles for eligibility and identified five trials (260 participants) that met inclusion criteria. The clinical conditions were: irritable bowel syndrome, depression, allergic rhinitis, back pain, and attention deficit hyperactivity disorder. The risk of bias was moderate. We found a positive effect for nondeceptive placebos (standardized mean difference 0.88, 95% CI 0.62 to 1.14, P < 0.00001, I² = 1%).

CONCLUSIONS

Open-label placebos appear to have positive clinical effects compared to no treatment. Caution is warranted when interpreting these results due to the limited number of trials identified, lack of blinding, and the fact that positive messages were included alongside open-label placebos. Larger definitive trials are now warranted to explore the potential patient benefit of open-label placebos, to investigate the relative contributions of positive suggestions, and ethical implications.

Contextually Aided Recovery (CARe): a scientific theory for innate healing

BACKGROUND

The chiropractic profession emerged when scientific explanations for causes of health and disease were still in infancy and the co-existence of notions such as innate healing and vitalism were perhaps admissible within such a historical context. Notwithstanding, within the scientific culture of the 21^st Century all healthcare paradigms require evidential support which in regard these early concepts are in large part, absent. Nevertheless, a large body of emerging scientific evidence supports the existence of innate healing phenomena that may explain a plethora of clinical outcomes observed during chiropractic care. However, in contrast to the notion that removing the putative subluxation constitutes the mechanism by which this healing is initiated, the evidentially supported explanation is one that invokes the impact of contextual factors inherent in the skilful care and authority of the healthcare provider. This perspective is presented here as the scientific model of Contextually Aided Recovery (CARe).

MAIN BODY

This paper contends that;Contextual effects are powerful and desirable and are triggered by contextual factors present in all therapeutic encounters including those encountered in chiropractic practice.These factors can elicit large clinical effects with substantive evidence supporting pain, immune and motor modulation.The compartmentalisation of specific and non-specific effects is a biologically and scientifically false dichotomy, erroneously invoked to de-legitimise treatment approaches that expertly construct contextual healing scenarios.The use of factors to construct contextual healing scenarios that maximise positive (placebo) and minimize negative (nocebo) effects is a skilful clinical art within the multimodal approach that describes modern chiropractic care and should be presented and defended as a legitimate component of orthodox healthcare Clinical improvement during chiropractic care, beyond any biologically specific treatment effects of manipulation and other modalities, may be largely understood considering contextual factors as described by a Contextually Aided Recovery (CARe) model.