Chronic fatigue syndrome or myalgic encephalomyelitis remains a controversial illness category. This paper surveys the state of knowledge and attitudes about this illness and proposes that epistemic concerns about the testimonial credibility of patients can be articulated using Miranda Fricker’s concept of epistemic injustice. While there is consensus within mainstream medical guidelines that there is no known cause of CFS/ME, there is continued debate about how best to conceive of CFS/ME, including disagreement about how to interpret clinical studies of treatments. (...) Against this background, robust qualitative and quantitative research from a range of countries has found that many doctors display uncertainty about whether CFS/ME is real, which may result in delays in diagnosis and treatment for patients. Strikingly, qualitative research evinces that patients with CFS/ME often experience suspicion by health professionals, and many patients vocally oppose the effectiveness, and the conceptualization, of their illness as psychologically treatable. We address the intersection of these issues and healthcare ethics, and claim that this state of affairs can be explained as a case of epistemic injustice. We find evidence that healthcare consultations are fora where patients with CFS/ME may be particularly vulnerable to epistemic injustice. We argue that the marginalization of many patients is a professional failure that may lead to further ethical and practical consequences both for progressive research into CFS/ME, and for ethical care and delivery of current treatments among individuals suffering from this debilitating illness. (shrink)

In many countries, including patients are legally entitled to request copies of their clinical notes. However, this process remains time-consuming and burdensome, and it remains unclear how much of the medical record must be made available. Online access to notes offers a way to overcome these challenges and in around 10 countries worldwide, via secure web-based portals, many patients are now able to read at least some of the narrative reports written by clinicians. However, even in countries that have implemented (...) the practice many clinicians have resisted the idea remaining doubtful of the value of opening notes, and anticipating patients will be confused or anxious by what they read. Against this scepticism, a growing body of qualitative and quantitative research reveals that patients derive multiple benefits from reading their notes. We address the contrasting perceptions of this practice innovation, and claim that the divergent views of patients and clinicians can be explained as a case of epistemic injustice. Using a range of evidence, we argue that patients are vulnerable to epistemic injustice. Nonetheless, we conclude that the marginalisation of patients’ access to their health information exemplifies a form of epistemic exclusion, one with practical and ethical consequences including for patient safety. (shrink)

In many countries, including patients are legally entitled to request copies of their clinical notes. However, this process remains time-consuming and burdensome, and it remains unclear how much of the medical record must be made available. Online access to notes offers a way to overcome these challenges and in around 10 countries worldwide, via secure web-based portals, many patients are now able to read at least some of the narrative reports written by clinicians (‘open notes’). However, even in countries that (...) have implemented the practice many clinicians have resisted the idea remaining doubtful of the value of opening notes, and anticipating patients will be confused or anxious by what they read. Against this scepticism, a growing body of qualitative and quantitative research reveals that patients derive multiple benefits from reading their notes. We address the contrasting perceptions of this practice innovation, and claim that the divergent views of patients and clinicians can be explained as a case of epistemic injustice. Using a range of evidence, we argue that patients are vulnerable to (oftentimes, non-intentional) epistemic injustice. Nonetheless, we conclude that the marginalisation of patients’ access to their health information exemplifies a form of epistemic exclusion, one with practical and ethical consequences including for patient safety. (shrink)

Patients in around 20 countries worldwide are now offered online access to at least some of their medical records. Access includes test results, medication lists, referral information, and/or the very words written by clinicians (so-called ‘open notes’). In this paper, I discuss the possibility of one unintended negative consequence of patient access to their clinical notes—the potential to increase ‘nocebo effects’. A growing body of research shows that nocebo effects arise by engaging perceptual and cognitive processes that influence negative expectancies, (...) and as a consequence, adverse health effects. Studies show that increased awareness about the side effects of medications, the framing of information and the socioemotional context of care can increase the risk of nocebo effects. Connecting research into the nocebo effect with open notes provides preliminary support for the hypothesis that patient access to clinical notes might be a forum for facilitating unwanted nocebo effects. Furthermore, current findings indicate that we might expect to see systematic differences in how nocebo effects are experienced among different patient populations. The ethical implications of the tension between transparency and the potential for harm are discussed, with an emphasis on what open notes might mean for justice and equity in clinical care for a range of already marginalised patient populations. I argue that to resolve these challenges does not thereby justify ‘closed notes’, and conclude with suggestions for how health systems and clinicians might adapt to this innovation to reduce the risk of potential nocebo effects arising via this novel route. (shrink)

The doctor-patient relationship is built on an implicit covenant of trust, yet it was not until the post-World War Two era that respect for patient autonomy emerged as an article of mainstream medical ethics. Unlike their medical forebears, physicians today are expected to furnish patients with adequate information about diagnoses, prognoses and treatments. Against these dicta there has been ongoing debate over whether placebos pose a threat to patient autonomy. A key premise underlying medical ethics discussion is the notion that (...) the placebo effect necessitates patient deception. Indeed, the American Medical Association guidelines imply that placebo treatment necessary entails a form of deception. As a consequence of this assumption, the fulcrum of debate on the use of placebo treatment has hinged on whether that deception is ever justified. Recently performed experiments with open-label transparently prescribed placebos have begun to challenge the notion that deception is necessary in eliciting the placebo effect and such effects necessarily involve a binary distinction between autonomy and beneficence. In this article we focus on the content of disclosures in distinctive open-label, transparently disclosed placebo studies and inquire whether they might be said to invoke deception in clinical contexts, and if so, whether the deception is unethical. We find that open placebos may be said to involve equivocation over how placebos work. However, drawing on surveys of patient attitudes we suggest that this equivocation appears to be acceptable to patients. We conclude that open placebos fulfil current American Medical Association guidelines for placebo use, and propose future research directions for harnessing the placebo effect ethically. (shrink)

Increasing numbers of health organisations are offering some or all of their patients access to the visit notes housed in their electronic health records. In some countries, including Sweden and the USA, this innovation is advanced with patients using online portals to access their clinical records including the visit summaries written by clinicians. In many countries, patients can legally request copies of their records; however, open notes are different because this innovation offers patients rapid, real-time access via electronic devices. In (...) this brief report, we explore what open notes might mean for placebo use in clinical care. Survey research into patient access to their clinical notes shows that increased transparency enhances patients’ understanding about their medications and augments engagement with their care. We reflect on the consequences of access for placebo prescribing, particularly for the common practice of deceptive placebo use, in which patients are not aware they are being offered a placebo. In addition, we explore how open notes might facilitate placebo and nocebo effects among patients. Bridging placebo studies with medical ethics, we identify a range of empirical research gaps that now warrant further study. (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)

The use of ‘placebos’ in clinical practice is a source of continued controversy for physicians and medical ethicists. There is rarely any extensive discussion on what ‘placebos’ are and how they work. In this paper, drawing on Louhiala and Puustinen's work, the author proposes that the term ‘placebo effect’ be replaced in clinical contexts with the term ‘positive care effect’. Medical treatment always takes place in a ‘context of care’ that encompasses all the phenomena associated with medical intervention: it includes (...) the particular method of treatment, the interpersonal relationships between medical staff and the patient and other factors, including physicians' and patients' beliefs in the power of the treatment. Together, these phenomena can result in a full spectrum of therapeutic effects to the patient—from no effects, to small effects, to large effects. In cases where there are significant therapeutic benefits to the patient, ‘positive care effects’ may be spoken of. Since the ethical codes of the General Medical Council and the American Medical Association demand transparency with respect to patient treatment and insist on complete openness in ‘placebo’ usage, the author argues that, as a matter of conceptual rigour and consistency, if the term ‘placebo effect’ is replaced by ‘positive care effect’, these ethical codes appear to insist on transparency about all such beneficial components of treatment. Given that this appears to be a counterintuitive obligation, the author concludes the paper with some comments on the clinical consequences of this conceptual revision, including a brief discussion of how this important debate might develop. (shrink)

Compared with mainstream medicine and complementary and alternative therapies, the practice of psychotherapy has enjoyed a relative pass when it comes to ethical evaluation. Therefore, contributions to the, although slowly growing, body of literature on psychotherapy ethics are to be welcomed. In his paper ‘Psychotherapy, placebos, and informed consent’, Garson Leder takes issue with what he calls the ‘go open’ project in psychotherapy ethics—the idea that the so-called ‘common factors’ in therapy should be disclosed to prospective patients. Although Leder does (...) not give a detailed list, the common factors include therapist characteristics, patient characteristics, and the working alliance. He argues that the project advocating disclosure of these factors is flawed on two grounds: that information about common factors is not necessary for informed consent; and clarity about specific mechanisms of change in therapy is consistent with ‘many theory-specific forms of psychotherapy’. There are multiple serious problems with Leder’s critique of the recent literature, including how he represents the contours of the debate, which I list, and address in this response. (shrink)

Is it ever right to prescribe placebos to patients in clinical practice? The General Medical Council is ambivalent about the issue; the American Medical Association asserts that placebos can be administered only if the patient is (somehow) ‘informed’. The potential problem with placebos is that they may involve deception: indeed, if this is the case, an ethical tension arises over the patient's autonomy and the physician's requirement to be open and honest, and the notion that medical care should be the (...) primary concern. This paper examines the case of depression as an entry point for understanding the complexities of the prescription of placebos. Recent important meta-analyses of antidepressants claim that they are not significantly more effective in a clinical setting than placebos. Given that antidepressants have numerous adverse side effects and are hugely expensive, this provocative research has serious potential ethical and practical implications for patients and medical providers. Should placebos be prescribed in place of antidepressants? The case of depression highlights another important issue which medical ethical codes have hitherto overlooked: well-being is not synonymous with being realistic about oneself, one's circumstances and the future. While severely depressed individuals are unduly pessimistic about themselves and the world around them, treatment of depressed individuals can be deemed successful when patients have successfully attained those positive illusions that are indicative of psychological health. This is exactly what successful psychological treatments of depression seem to achieve. It is therefore possible that there may be a limited unavoidable role for deception in medicine. (shrink)

Major depressive disorder is not only the most widespread mental disorder in the world, it is a disorder on the rise. In cases of particularly severe forms of depression, when all other treatment options have failed, the use of electroconvulsive therapy (ECT) is a recommended treatment option for patients. ECT has been in use in psychiatric practice for over 70 years and is now undergoing something of a restricted renaissance following a sharp decline in its use in the 1970s. Despite (...) its success in treating severe depression there is continued debate as to the effectiveness of ECT: in some studies, it is argued that ECT is marginally more effective than sham ECT. In addition, there is still no clear explanation of how ECT works; among the range of hypotheses proposed it is claimed that ECT may work by harnessing placebo effects. In light of the uncertainties over the mechanism of action of ECT and given the risk of serious side effects that ECT may produce, I contend that the process of informed consent must include comprehensive accounts of these uncertainties. I examine the possible consequences of providing adequate information to potential ECT patients, including the consideration that ECT may still prove to be effective even if physicians are open about the possibility of it working as a placebo. I conclude that if we value patient autonomy as well as the professional reputation of medical practitioners, a fuller description of ECT must be provided to patients and their carers. (shrink)

Shamans, healers, and doctors have always known that patients may improve even if no real therapy is administered. In the Charmides, Plato noted that to soothe a headache, one needed "a kind of leaf, which required to be accompanied by a charm, and if a person would repeat the charm at the same time he used the cure, he would be made whole; but that without the charm would be of no avail". Similarly, more than two millennia later, Thomas Jefferson (...) observed, "One of the most successful physicians I have even known has assured me that he used more bread pills, drops of colored water, and powder of hickory ashes, than of all other medication put together"; Jefferson famously labeled this... (shrink)

A common observation in placebo studies is that definitional disagreement is rife. Philosopher and historian of science Robin Nunn recently argued that "Nobody who came and saw the placebo has conquered its definition". Nunn insists that "the placebo construct conceals more than it clarifies," and that we need to prepare for "a post-placebo paradigm". Pronouncements that disagreement is endemic are often the prologue for new definitions of placebo and "placebo effect": for example, in the opening of a recent philosophical paper (...) on the issue, Jeremy Howick observed that debates about placebos "rage," and that "there is currently no widely accepted definition of the 'placebo'".... (shrink)

I am grateful for the variety of feedback. Three themes struck me: first, commentators recognised the value of open notes but underlined the importance of exploring unintended consequences of the innovation particularly for already disadvantaged populations; second, they suggested nocebo effects might arise via additional routes not identified in my paper; third, they signalled the need for further empirical and ethical exploration of nocebo effects. Exploring all three issues and offering a commentary that was equal parts intriguing and perturbing, Chang (...) and Torous proposed nocebo effects and other harms might be ubiquitous in the digital health space. 1 For example, they hypothesised that the preoccupation with checking health tracking data including adverse readings or outcomes available via downloadable apps and wearable devices might induce nocebo effects. This supposition is worthy of further scrutiny. Chang and Torous also highlighted the lack of research into potentially disparate effects of digital... (shrink)

While a significant body of bioethical literature considers how the placebo effect might introduce a conflict between autonomy and beneficence, the link between justice and the placebo effect has been neglected. Here, we bring together disparate evidence from the field of placebo studies and research on health inequalities related to race and ethnicity, and argue that, collectively, this evidence may provide the basis for an unacknowledged route by which health disparities are exacerbated. This route is constituted by an uneven distribution (...) of placebo effects, resulting from differences in expressions of physician warmth and empathy, as well as support and patient engagement, across racial and ethnic lines. In a discussion of the ethical implications of this connection, we argue that this contribution to health disparities is a source of injustice, consider ways in which these disparities might be ameliorated and suggest that this conclusion is likely to extend to other realms of inequality as well. (shrink)

It is now an ethical dictum that patients should be informed by physicians about their diagnosis, prognosis and treatment options. In this paper, I ask: ‘How informed are the ‘informers’ in clinical practice?’ Physicians have a duty to be ‘well-informed’: patient well-being depends not just in conveying adequate information to patients, it also depends on physicians keeping up-to-date about: popular misunderstandings of illnesses and treatments; and the importance of patient psychology in affecting prognosis. Taking the case of depression as an (...) entry point, this paper argues that medical researchers and physicians need to pay serious attention to the explanations given to patients regarding their diagnosis. Studies on lay understanding of depression show that there is a common belief that depression is wholly caused by a ‘chemical imbalance’ that can be restored by chemically restorative antidepresssants, a claim that has entered ‘folk wisdom’. However, these beliefs oversimplify and misrepresent the current scientific understanding of the causes of depression: first, there is consensus in the scientific community that the causes of depression include social as well as psychological triggers ; second, there is significant dissensus in the scientific community over exactly what lower level, biological or biochemical processes are involved in causing depression; third, there is no established consensus about how antidepressants work at a biochemical level; fourth, there is evidence that patients are negatively affected if they believe their depression is wholly explained by of ‘biochemical imbalance’. I argue that the medical community has a duty, to provide patients with adequate information and to be aware of the negative health impact of prevalent oversimplifications—whatever their origins. (shrink)

Providing a concise definition of hope is challenging. Psychologists alone have proposed 26 theories of hope and 54 definitions thereof. The difficulty of finding a universal definition of hope was summed up by the philosopher Joseph Godfrey who admitted, "I'd rather have hope than be able to define it". Part of the problem is that the concept is the object of scrutiny across many different scholarly disciplines, each of which have their own, sometimes divergent, methodologies and interests in the concept. (...) Notwithstanding these idiosyncrasies, many of the respective disciplines, if not all, have the potential to improve the understanding of... (shrink)

I thank Julie Hersh for her thoughtful and valuable comments on the use of electroconvulsive therapy .1 Discussions with those who have experience of treatments is of the utmost importance when debating issues such as informed consent. I am therefore very pleased to be given this opportunity to respond. Hersh offers three main criticisms of my paper but I hope to show that the tenets of the paper are not undermined by her commentary.Hersh's first criticism stems from her personal experience: (...) she claims that, ‘The results of ECT for me were miraculous’. She argues that ECT ‘works’ and we have ‘70 years of remarkably positive experience’ to support this fact. In response, I agree that there are certainly patients who believe that ECT has been a highly effective intervention: but equally, there are others who have experienced intolerable side effects as a result.2 ECT is a controversial treatment precisely because of the serious long-term risk of memory loss.3 ,4 If we are to strive for the best healthcare possible, we cannot base our conclusions merely on positive cases: we need to consider all cases . Thus, I reject her conclusion that ECT is ‘remarkably positive’ for all patients: studies do not unequivocally support Hersh's fortunate experiences. In addition, I must also challenge the assumption that ECT ‘works’. Counterintuitive as …. (shrink)

Physical environmental factors – or ‘artifacts’ – are linked to healthcare outcomes in the field of social psychology. However, the role of artifacts remains rarely examined in the burgeoning discipline of placebo studies. In this paper, we argue that a careful consideration of artifacts – such as provider clothing and office décor – may carry significant potential in eliciting placebo effects in clinical settings. We discuss three potential mechanisms by which artifacts may enhance or diminish placebo (or nocebo) effects: classical (...) conditioning, response expectancy, and mindsets. We propose testable hypotheses and conclude by providing innovative research designs that might help to better advance this novel research agendum. (shrink)

Patient online record access (ORA) is spreading worldwide, and in some countries, including Sweden, and the USA, access is advanced with patients obtaining rapid access to their full records. In the UK context, from 31 October 2023 as part of the new NHS England general practitioner (GP) contract it will be mandatory for GPs to offer ORA to patients aged 16 and older. Patients report many benefits from reading their clinical records including feeling more empowered, better understanding and remembering their (...) treatment plan, and greater awareness about medications including possible adverse effects. However, a variety of indirect evidence suggests these benefits are unlikely to accrue without supplementation from internet-based resources. Using such routes to augment interpretation of the data and notes housed in electronic health records, however, comes with trade-offs in terms of exposing sensitive patient information to internet corporations. Furthermore, increased work burdens on clinicians, including the unique demands of ORA, combined with the easy availability and capability of a new generation of large language model (LLM)-powered chatbots, create a perfect collision course for exposing sensitive patient information to private tech companies. This paper surveys how ORA intersects with internet associated privacy risks and offers a variety of multilevel suggestions for how these risks might be better mitigated. (shrink)

In their thoughtful paper, Shen et al. (2024) discuss optimal solutions to address the challenge of returning individual research results from digital phenotyping in psychiatry. Their conclusion to...

Myalgic encephalomyelitis or chronic fatigue syndrome is a contested illness category. This paper investigates the common claim that patients with ME/CFS—and by extension, ME/CFS patient organizations —exhibit “militant” social and political tendencies. The paper opens with a history of the protracted scientific disagreement over ME/CFS. We observe that ME/CFS POs, medical doctors, and medical researchers exhibit clear differences in opinion over how to conceptualize this illness. However, we identify a common trope in the discourse over ME/CFS: the claim of “militant” (...) patient activism. Scrutinizing this charge, we find no compelling evidence that the vast majority of patients with ME/CFS, or the POs representing them, have adopted any such militant political policies or behaviours. Instead, we observe key strategic similarities between ME/CFS POs in the United Kingdom and the AIDs activist organizations of the mid-1980s in the United States which sought to engage scientists using the platform of public activism and via scientific publications. Finally, we explore the contours of disagreement between POs and the medical community by drawing on the concept of epistemic injustice. We find that widespread negative stereotyping of patients and the marginalization and exclusion of patient voices by medical authorities provides a better explanation for expressions of frustration among patients with ME/CFS. (shrink)

Tamara Browne proposes a provocative idea: She argues that philosophers, sociologists, and bioethicists should act as an independent editorial panel for future editions of the Diagnostic and Statistical Manual of Mental Disorders. Her paper depends on some well-versed claims in philosophy of psychiatry: She argues that psychiatric classifications are inherently value laden and philosophers, sociologists, and ethicists are best placed to discern the values are that embedded within scientific descriptions of mental disorders, and to speculate on the effects of any (...) such classifications on individuals and the populace at large as a result of these classifications.I agree with Browne that the DSM (and... (shrink)

A growing body of cross-cultural survey research shows high percentages of clinicians report using placebos in clinical settings. One motivation for clinicians using placebos is to help patients by capitalising on the placebo effect’s reported health benefits. This is not surprising, given that placebo studies are burgeoning, with increasing calls by researchers to ethically harness placebo effects among patients. These calls propose placebos/placebo effects offer clinically significant benefits to patients. In this paper, we argue many findings in this highly cited (...) and ‘hot’ field have not been independently replicated. Evaluating the ethicality of placebo use in clinical practice involves first understanding whether placebos are efficacious clinically. Therefore, it is crucial to consider placebo research in the context of the replication crisis and what can be learnt to advance evidence-based knowledge of placebos/placebo effects and their clinical relevance (or lack thereof). In doing so, our goal in this paper is to motivate both increased awareness of replication issues and to help pave the way for advances in scientific research in the field of placebo studies to better inform ethical evidence-based practice. We argue that, only by developing a rigorous evidence base can we better understand how, if at all, placebos/placebo effects can be harnessed ethically in clinical settings. (shrink)

Randomised placebo-controlled trials (RPCTs) are the gold standard for evaluating novel treatments. However, this design is rarely used in the context of orthopaedic interventions where participants are assigned to a real or placebo surgery. The present study examines attitudes towards RPCTs for orthopaedic surgery among 687 orthopaedic surgeons across the USA. When presented with a vignette describing an RPCT for orthopaedic surgery, 52.3% of participants viewed it as ‘completely’ or ‘mostly’ unethical. Participants were also asked to rank-order the value of (...) five different types of evidence supporting the efficacy of a surgery, ranging from RPCT to an anecdotal report. Responses regarding RPCTs were polarised with 26.4% viewing it as the least valuable (even less valuable than an anecdote) and 35.7.% viewing it as the most valuable. Where equipoise exists, if we want to subject orthopaedic surgeries to the highest standard of evidence (RPCTs) before they are implemented in clinical practice, it will be necessary to educate physicians on the value and ethics of placebo surgery control conditions. Otherwise, invasive procedures may be performed without any benefits beyond possible placebo effects. (shrink)

Over 200 years ago, doctors' most effective tools were typically not found in their medical bags. Indeed, most treatments in the history of medicine have, until relatively recently, caused more harm than good. Prior to the biomedical revolution in the late 19th century, doctors' most reliable and effective instruments of healing were their skills of communication with patients and an aptitude for a positive and supportive bedside manner. Bearing out this portrait of medicine, Thomas Jefferson, writing in 1807, noted that (...) "one of the most successful physicians I have ever known has assured me that he used more bread pills, drops of colored water, and powers of hickory ashes, than of all other medicines put together"... (shrink)

This paper aims to show that the classification by the American Psychiatric Association in the Diagnostic and Statistical Manual of Mental Disorders of a distinct listing of disorders known as Culture-Bound Syndromes is misguided. I argue that the list of CBS comprises either genuine disorders that should be included within the main body of the DSM; or ersatz-disorders that serve a practical role for psychiatrists dealing with patients from certain cultures but will one day be eliminated or assimilated by bona (...) fide DSM classifications. In support of these views I draw on claims from two key themes in the philosophy of science: the claim that all folk explanations for phenomena are thoroughly theoretical and therefore fallible; and the occurrence of theoretical elimination in the history of science. I contend that any ersatz-disorders located in the DSM that are judged to be radically false do not differ in kind from eliminated theories in the history of pre-science. (shrink)

Nunn's critique of the placebo concept is a radical and refreshing contribution to the debate. While there is much that can be contested in his analysis, his use of empirical and theoretical arguments to defend his conclusion - that the time has come to abandon the placebo construct altogether - presents an important challenge.