Semiotics and the placebo effect

Despite substantial progress in elucidating its neurobiological mechanisms, theoretical understanding of the placebo effect is poorly developed. Application of the semiotic theory developed by the American philosopher Charles Peirce offers a promising account of placebo effects as involving the apprehension and response to signs. The semiotic approach dovetails with the various psychological mechanisms invoked to account for placebo effects, such as conditioning and expectation, and bridges the biological and cultural dimensions of this fascinating phenomenon.     

William James, faith, and the placebo effect

Long considered a fact of medicine and of clinical investigation, the placebo effect has recently been challenged. The thought of the great American psychologist and philosopher William James, particularly his understanding of the practical value of faith, helps to illuminate the nature of the placebo effect and the implications of this puzzling phenomenon for understanding healing and the practice of medicine.     

A conditioned response model of the placebo effect

A model of the placebo response as a conditioned response(CR) is presented and predictions from this model are listed. Through association with active ingredients(UCS), neutral(CS) places, persons, procedures, and things can come to acquire the ability to reduce pain, anxiety, and depressive responses. One major counterintuitive prediction from the model is that therapists who routinely use active ingredients(UCS) or powerful drugs will get stronger placebo effects than those who routinely use inert ingredients(CS) or weak drugs. Developmentally, placebo responding appears to involve two successive conditioning stages, which may involve first the left and later the right hemisphere in right-handed subjects. The relationship between placebo responding and hypnotizability is discussed.This paper was first presented at the San Diego Biomedical Symposium (invited paper), San Diego, California, November 1977. Later it was presented at a symposium on Non-Specific Effects in Biofeedback, Biofeedback Society of America, Albuquerque, New Mexico, February 1978. It has been published in abbreviated form inProceedings of the San Diego Biomedical Symposium, New York: Academic Press, 1977. I would like to thank G. E. Schwartz for encouraging me to repackage this model for left brain (critical analytic) consumers, and particularly for his encouragement and critical comments during the review process.     

Understanding the placebo effect from an evolutionary perspective

A placebo is a treatment which is not effective through its direct action on the body, but works because of its effect on the patient's beliefs. From an evolutionary perspective, it is initially puzzling why, if people are capable of recovering, they need a placebo to do so. Based on an argument put forward by Humphrey [Great expectations: the evolutionary psychology of faith-healing and the placebo effect. In: Humphrey, N (2002). The mind made flesh. Oxford University Press, Oxford. 255–285], we present simple mathematical models of the placebo effect that involve a trade-off between the costs and benefits of allocating resources to a current problem. These models show why the effect occurs and how its magnitude and timing can depend on different factors. We identify a particular aspect of belief which may govern the effect and conclude that a deeper understanding of why the placebo effect exists may allow it to be invoked more easily in the future.     

The placebo effect: how the subconscious fits in

The placebo effect is very well known, being replicated in many scientific studies. At the same time, its exact mechanisms still remain unknown. Quite a few hypothetical explanations for the placebo effect have been suggested, including faith, belief, hope, classical conditioning, conscious/subconscious expectation, endorphins, and the meaning response. This article argues that all these explanations may boil down to autosuggestion, in the sense of "communication with the subconscious." An important implication of this is that the placebo effect can in principle be used effectively without the placebo itself, through a direct use of autosuggestion. The benefits of such a strategy are clear: fewer side effects from medications, huge cost savings, no deception of patients, relief of burden on the physician's time, and healing in domains where medication or other therapies are problematic.     

Harnessing the placebo effect: the need for translational research

Laboratory research recently has greatly enhanced the understanding of placebo and nocebo effects by identifying specific neuromodulators and brain areas associated with them. However, little progress has been made in translating this knowledge into improved patient care. Here, we discuss the limitations in our knowledge about placebo (and nocebo) effects and the need for translational research with the aim of guiding physicians in maximizing placebo effects and minimizing nocebo effects in their routine clinical practice. We suggest some strategies for how, when and why interventions to promote beneficial placebo responses might be administered in the clinical setting.     

Predicting potential placebo effect in drug treated subjects

Non-specific responses to treatment (commonly known as placebo response) are pervasive when treating mental illness. Subjects treated with an active drug may respond in part due to non-specific aspects of the treatment, i.e, those not related to the chemical effect of the drug. To determine the extent a subject responds due to the chemical effect of a drug, one must disentangle the specific drug effect from the non-specific placebo effect. This paper presents a unique statistical model that allows for the separate prediction of a specific effect and non-specific effects in drug treated subjects. Data from a clinical trial comparing fluoxetine to a placebo for treating depression is used to illustrate this methodology.     

Biofeedback and applied psychophysiology at the crossroads

Biofeedback and applied psychophysiology, as tools, as objects of scientific inquiry, and as clinical interventions, have progressed from speculative experiment to data-based research, from trial clinical intervention to efficacy studies and accountability. These are multidisciplinary approaches, crossing the boundary between traditional professions such as medicine, psychology, physical therapy, occupational therapy, and other health care related fields. Along the way we as an Association, our members both scientists and practitioners, have encountered the many hurdles and stumbling blocks that stand in the way of developing new technologies. How we deal with these obstacles shapes us as a group and shapes the perceptions of others who view us. An attempt will be made to place the current development of the field within the context of the rapidly changing health care environment, and to address the challenges, and sometimes conflicting demands, of experimental science and clinical practice.     

Biofeedback efficacy studies

Biofeedback, a field still in its infancy, has developed treatments that have been used with clinical success in the treatment of a number of disorders. Many have expressed their public concern that biofeedback has not lived up to its early promise and that it has not developed treatments that are, in fact, efficacious. A number of factors, which are inherent in biofeedback research, confound the results of clinical efficacy studies of biofeedback treatments. Researchers interested in the efficacy of biofeedback must address several issues: (1) Rejecting the null hypothesis is not equal to proving the null hypothesis (without the use of power analysis); (2) control for nonspecific effects is not equal to a double-blind experimental design; (3) ignorance of a mechanism of action is not equal to a lack of clinical efficacy; (4) the administration of training is not equal to the subject's learning to criterion; (5) untrained therapists are not equal to trained therapists; (6) statistical significance is not equal to clinical significance; and (7) the laboratory setting is not equal to the clinical setting.     

The Raynaud's Treatment Study: Biofeedback Protocols and Acquisition of Temperature Biofeedback Skills

The Raynaud's Treatment Study (RTS) compared temperature biofeedback training and a behavioral control procedure (frontalis EMG biofeedback) with nifedipine-XL and a medication placebo for treatment of primary Raynaud's phenomenon (RP) in a large (N = 313) multicenter trial. The present study describes the RTS biofeedback protocols and presents data on the acquisition of digital skin temperature and frontalis EMG responses in the RTS. The findings point to substantial problems with acquisition of physiological self-regulation skills in the RTS. Only 34.6% of the Temperature Biofeedback group (N = 81) and 55.4% of the EMG Biofeedback group (N = 74) successfully learned the desired physiological response. In contrast, 67.4% of a Normal Temperature Biofeedback group (N = 46) learned hand warming. Multivariate analysis found that coping strategies, anxiety, gender, and clinic site predicted acquisition of hand-warming skills whereas variables related to RP disease severity did not. Physiological data showed vasoconstriction in response to the onset of biofeedback and also found that performance in the initial sessions was critical for successful acquisition. These findings indicate that attention to the emotional and cognitive aspects of biofeedback training, and a degree of success in the initial biofeedback sessions, are important for acquisition.     

Biofeedback therapy in the colon and rectal practice

In coloproctology, biofeedback has been used for more than 20 years to treat patients with fecal incontinence, constipation, and rectal pain. It can be performed in a number of conditions with minimal risk and discomfort. However, it does require the presence of some degree of sphincter contraction and rectal sensitivity. Biofeedback can be time-consuming and demands motivation. The purpose of this paper is to review the indications, methodology, and results of anorectal biofeedback in the treatment of these disorders. Mean success rates for biofeedback range from 72.3% for fecal incontinence of diverse etiology, 68.5% for constipation attributable to paradoxical puborectalis syndrome, and 41.2% for idiopathic rectal pain. However, criteria to define success vary tremendously among researchers and there is a tendency to indicate biofeedback in a myriad of conditions when other therapeutic options, including surgery, fail or are inappropriate. These factors make comparison of the results difficult and reinforce the need for randomized controlled trials and studies assessing long-term follow-up. In summary, biofeedback is a simple, cost-effective, and morbidity-free technique and remains an attractive option, especially considering the complexity of the functional disorders of the colon, rectum, anus, and pelvic floor.