The placebo effect is now generally defined widely as an individual’s response to the psychosocial context of a clinical treatment, as distinct from the treatment’s characteristic physiological effects. Some researchers, however, argue that such a wide definition leads to confusion and misleading implications. In response, they propose a narrow definition restricted to the therapeutic effects of deliberate placebo treatments. Within the framework of modern medicine, such a scope currently leaves one viable placebo treatment paradigm: the non-deceptive and non-concealed administration of (...) ‘placebo pills’, or open label placebo (OLP) treatment. In this paper I consider how the placebo effect occurs in OLP. I argue that a traditional belief-based account of OLP is paradoxical. Instead, I propose an account based on the non-doxastic attitude of pretence, understood within a fictionalist framework. (shrink)

Nursing knowledge stems from a dynamic interplay between population‐based scientific knowledge (the general) and specific clinical cases (the particular). We compared the ‘cascade model of knowledge translation’, also known as ‘classical biomedical model’ in clinical practice (in which knowledge gained at population level may be applied directly to a specific clinical context), with an emergentist model of knowledge translation. The structure and dynamics of nursing knowledge are outlined, adopting the distinction between epistemic and non‐epistemic values. Then, a (moderately) emergentist approach (...) to nursing knowledge is proposed, based on the assumption of a two‐way flow from the general to the particular and vice versa. The case of the ‘placebo effect’ is analysed as an example of emergentist knowledge. The placebo effect is usually considered difficult to be explained within the classical biomedical model, and we underscore its importance in shaping nursing knowledge. In fact, nurses are primarily responsible for administering placebo in the clinical setting and have an essential role in promoting the placebo effect and reducing the nocebo effect. The beliefs responsible for the placebo effect are as follows: (1) interactive, because they depend on the relationship between patients and health care professionals; (2) situated, because they occur in a given clinical context related to certain rituals; and (3) grounded on higher order beliefs concerning what an individual thinks about the beliefs of others. It is essential to know the clinical context and to understand other people's beliefs to make sense of the placebo effect. The placebo effect only works when the (higher order) beliefs of doctors, nurses and patients interact in a given setting. Finally, we argue for a close relationship between placebo effect and nursing knowledge. (shrink)

In 2009, the UK House of Commons Science and Technology Committee conducted an ‘evidence check’ on homeopathy to evaluate evidence for its effectiveness. In common with the wider literature critical of homeopathy, the STC report seems to endorse many of the strong claims that are made about its implausibility. In contrast with the critical literature, however, the STC report explicitly does not place any weight on implausibility in its evaluation. I use the contrasting positions of the STC and the wider (...) critical literature to examine the ‘implausibility arguments’ against homeopathy and the place of such arguments within evidence-based medicine. I argue that the STC report undervalues its strong claims about the mechanistic plausibility of homeopathy because it relies on a misunderstanding about the role of mechanistic evidence within EBM. This is not a conclusion for a revision of the role mechanistic evidence plays within EBM, however. It is a conclusion about the inconsistency of the STC report’s position towards implausibility arguments, given the evidential claims they endorse and the atypical situation that homeopathy presents. It provides a further example of the general point that mechanistic reasoning should not be seen as providing categorically lower quality evidence. (shrink)

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 received one bottle of water, which they were asked to refill themselves each day during a 2-week intervention period. In Experiment 2, participants received a new sealed water bottle every day. In both experiments, participants were randomly assigned to one of four groups: no treatment, open-label placebo without rationale, open-label placebo with rationale, and open-label placebo with additional rationale in a suggested relaxed state. 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. (shrink)

Placebos are commonly defined as ineffective treatments. They are treatments that lack a known mechanism linking their properties to the properties of the condition on which treatment aims to intervene. Given this, the fact that placebos can have substantial therapeutic effects looks puzzling. The puzzle, we argue, arises from the relationship placebos present between culturally meaningful entities, our intentional relationship to the environment and bodily effects. How can a mere attitude toward a treatment result in appropriate bodily changes? We argue (...) that an ‘enactive’ conception of cognition accommodates and renders intelligible the phenomenon of placebo effects. Enactivism depicts an organism’s adaptive bodily processes, its intentional directedness, and the meaningful properties of its environment as co-emergent aspects of a single dynamic system. In doing so it provides an account of the interrelations between mind, body and world that demystifies placebo effects. (shrink)

Despite a wealth of findings that psychotherapy is an effective psychological intervention the principal mechanisms of psychotherapy change are still in debate. It has been suggested that all forms of psychotherapy provide a context which enables clients to transform the meaning of their experiences and symptoms in such a way as to help clients to feel better, and function more adaptively. However, psychotherapy is not the only healthcare intervention that has been associated with ‘meaning’: the reason why placebo have effects (...) has also been proposed to be a ‘meaning response’. Thus, it has been argued that the meaning of treatments has a central impact on beneficial (and by extension, negative) health-related responses. In light of the strong empirical support of a contextual understanding of psychotherapy and its effects, the aim of this conceptual analysis is to examine the role of meaning and its transformation in psychotherapy – in general – and within three different, commonly-used psychotherapy modalities. (shrink)

In the biomedical, behavioural and social sciences, the leading method used to estimate causal effects is commonly randomised controlled trials (RCTs) that are generally viewed as both the source and justification of the most valid evidence. In studying the foundation and theory behind RCTs, the existing literature analyses important single issues and biases in isolation that influence causal outcomes in trials (such as randomisation, statistical probabilities and placebos). The common account of biased causal inference is described in a general way (...) in terms of probabilistic imbalances between trial groups. This paper expands the common account of causal bias by distinguishing between the range of biases arising between trial groups but also within one of the groups or across the entire sample during trial design, implementation and analysis. This is done by providing concrete examples from highly influential RCT studies. In going beyond the existing RCT literature, the paper provides a broader, practice-based account of causal bias that specifies the between-group, within-group and across-group biases that affect the estimated causal results of trials – impacting both the effect size and statistical significance. Within this expanded framework, we can better identify the range of different types of biases we face in practice and address the central question about the overall validity of the RCT method and its causal claims. A study can face several smaller biases (related simultaneously to a smaller sample, smaller estimated effect, greater unblinding etc.) that generally add up to greater aggregate bias. Though difficult to measure precisely, it is important to assess and provide information in studies on how much different sources of bias, combined, can explain the estimated causal effect. The RCT method is thereby often the best we have to inform our policy decisions – and the evidence is strengthened when combined with multiple studies and other methods. Yet there is room for continually improving trials and identifying ways to reduce biases they face and to increase their overall validity. Implications are discussed. (shrink)

Arguments that medical decision making should rely on a variety of evidence often begin from the claim that meta-analysis has been shown to be problematic. In this paper, I first examine Stegenga’s argument that meta-analysis requires multiple decisions and thus fails to provide an objective ground for medical decision making. Next, I examine three arguments from social epistemologists that contend that meta-analyses are systematically biased in ways not appreciated by standard epistemology. In most cases I show that critiques of meta-analysis (...) fail to account for the full range of meta-analytic procedures. In the remainder of cases, I argue that the critiques identify problems that do not uniquely cut against meta-analysis. I close by suggesting one reason why it may be pragmatically rational to violate the principle of total evidence and by outlining the criteria for a successful argument against meta-analysis. A set of criteria I contend remain unmet. (shrink)

Nocebo effects occur when an individual experiences undesirable physiological reactions caused by doxastic states that are not a treatment’s core or characteristic features.1 As Scott Gelfand2 points out, there are numerous studies that have shown that the disclosure of a treatment’s side effects to a patient increases the risk of the side effects. From an ethical point of view, nocebo effects caused by the disclosures of side effects present a challenging problem. On the one hand, clinicians’ duty to inform patients (...) of the consequences (including possible side effects) of their treatments is critical in ensuring that patients’ autonomy is respected. Patients cannot act autonomously if relevant information is withheld from them (without their consent, perhaps). On the other hand, clinicians also ought to minimize harm to patients. (shrink)

Philosophical Investigations, Volume 45, Issue 4, Page 414-429, October 2022.

This paper offers a critical analysis of several accounts of the placebo effect that have been put forward. While the placebo effect is most often thought of as a control in research and as a deceptive tool in practice, a growing body of research suggests that it ought to be thought of as a powerful phenomenon in its own right. Several accounts that aim to draw boundaries around the placebo effect are evaluated in relation to current evidence and it is (...) argued that none of them adequately capture the variability and potency of the phenomenon. Two accounts, however, that point towards the underlying mechanisms of the placebo effect, are shown to offer promise in terms of developing a more comprehensive account of the placebo effect. (shrink)

Side effects are ubiquitous in medicine and they often play a role in treatment decisions for patients and clinicians alike. Philosophers and health researchers often use side effects to illustrate issues with contemporary medical research and practice. However, technical definitions of ‘side effect’ differ among health authorities. Thus, determining the side effects of an intervention can differ depending on whose definition we assume. Here I review some of the common definitions of side effect and highlight their issues. In response, I (...) offer an account of side effects as jointly (i) unintended and (ii) effects due to the causal capacities or invariances of an intervention. I discuss (i) by examining the intentions or reasons behind therapeutic interventions, and I discuss (ii) by appealing to a manipulationist model of causation. The analysis here highlights that side effects are conceptually distinct from related outcomes like adverse events, adverse drug reactions, and placebo effects. The analysis also allows for reflection on the utility of ‘side effect’ as a technical term in medical research and practice. (shrink)

Nocebo effects occur when an individual experiences undesirable physiological reactions caused by doxastic states that are not a treatment’s core or characteristic features.1 As Scott Gelfand2 points out, there are numerous studies that have shown that the disclosure of a treatment’s side effects to a patient increases the risk of the side effects. From an ethical point of view, nocebo effects caused by the disclosures of side effects present a challenging problem. On the one hand, clinicians’ duty to inform patients (...) of the consequences (including possible side effects) of their treatments is critical in ensuring that patients’ autonomy is respected. Patients cannot act autonomously if relevant information is withheld from them (without their consent, perhaps). On the other hand, clinicians also ought to minimize harm to patients. (shrink)

This article presents and defends an integrated view of the placebo effect, termed “affective-meaning-making” model, which draws from theoretical reflection, clinical outcomes, and neurophysiological findings. We consider the theoretical limitations of those proposals associated with the “meaning view” on the placebo effect which leave the general aspects of meaning unspecified, fail to analyze fully the role of emotions and affect, and establish no clear connection between the theoretical, physiological, and psychological aspects of the effect. We point out that a promising (...) way to overcome these limitations is given by grounding the placebo effect on Peirce’s theory of meaning, in which the role of the meaning constitution and change is placed in logical and objective structures. We also show the connection between our theoretical proposal and the appraisal theory and integrate it with emotion regulation. (shrink)

In the field of placebo studies residual disagreement about the terminology ‘placebo’ and ‘placebo effect’ still persists. We differentiate between the conceptualization of placebos in clinical trials; and placebo effects understood as a psychobiological phenomenon. With respect to the latter, we argue that a scientific ‘placebo paradigm’ has emerged, indicating that—at least among placebo scientists—there exists relatively stable consensus about how to conceive of placebo effects. We claim that existence of a placebo paradigm does not protect concepts from revision; nonetheless, (...) we argue that scientific progress is dependent on, and guided by relative conceptual stability. Therefore, to mount persuasive arguments for conceptual revision in respect of ‘placebo effects’ we argue, critics either need to defend the claim that a placebo paradigm is not underway, or that there are major scientific failings in respect of it. With these considerations in mind we examine three alternative proposals for conceptual reform: Grünbaum/Howick’s relativity models of placebo concepts; Moerman/Brody’s meaning response; and Nunn/Turner’s proposal for conceptual eliminativism. We derive two conclusions from this evaluation. First, we conclude that no convincing arguments have so far been presented for conceptual overhaul of ‘placebo effects.’ Notwithstanding this analysis, we conclude that refinement of this concept is likely. Second, we agree with Turner and Nunn that the term ‘placebo’ in the context of randomized controlled trials remains a source of confusion for many researchers, risking the design and scientific integrity of clinical findings. Therefore, in these contexts, replacing the term ‘placebo’ with ‘control’ is justified. (shrink)