Science of the Placebo: Toward an Interdisciplinary Research Agenda

Do placebos work? For many conditions, you bet they do! Maybe in some people most of the time; maybe even in all people some of the time. Those are among the conclusions that experts drew from a comprehensive review of placebo effects that took place at the National Institutes of Health. The meeting, designed to bring basic biomedical and behavioral scientists together with clinicians and clinical trial experts, developed an expanded concept of the placebo, explored a variety of explanatory mechanisms of why placebos work when they work, and discussed the pros and cons of using placebos in clinical trials. The experts went on to develop a research agenda to further progress in the field. The result is a new look at placebos, one that calls for careful consideration of the complex ethical issues involved in exploiting placebo effects, but sees their potential as therapeutic allies in clinical practice. The chapters serve as an essential practical and theoretical guide to practitioners, researchers, bioethicists, patients, and students who want a comprehensive review of the state of placebo science and placebo–controlled clinical trials. They include: The historical context and ethical perspectives Explanatory psychosocial and physiological mechanisms (for example, social and cultural meanings, classic conditioning, social learning, intervening psychophysiology) The need to distinguish placebo effects from biological and statistical artifacts Issues concerning the use of placebo groups in clinical trials: ethics, methodological issues, pros, cons, and alternatives Priorities for future research The publication of this book has important implications for clinical medicine, making it essential reading for clinical researchers, basic scientists and health care practitioners.

Contributors.

Foreword.

1 An Overview.

Section 1: Historical and Ethical Perspectives.

2 Seeing the Placebo Effect: Historical Legacies and Present Opportunities.

3 Ethical Issues in Use of Placebo in Medical Practice and Clinical Trials.

Section 2: Elucidating Placebo Effects: Explanatory Mechanisms.

4 Explanatory Mechanisms for Placebo Effects: Cultural Influences and the Meaning Response.

5 Explanatory Mechanisms for Placebo Effects: Cognition, Personality and Social Learning.

6 Explanatory Mechanisms for Placebo Effects: Pavlovian Conditioning.

7 Regression to the Mean or Placebo Effect?.

Section 3: Elucidating Placebo Effects: Intervening Psychophysiology.

8 Neuriendocrine Meidators of Placebo Effects on Immunity.

9 Endogenous Opioid and Non–Opioid Pathways as Mediators of Placebno Analgesia.

Section 4: Use of Placebo Groups in Clinical Trials–Methodological and Ethical Issues.

10 Placebo controlled Trials and Active Controlled Trials: Ethics and Inference.

11 When is it Appropriate to Use a Placebo Arm in a Trial?.

12 The Pros and Cons of Non–Inferiority (Equivalence) Trials.

13 Use of Placebo in Large–Scale, Pragmatic Trials.

14 Placebo Controls in Clinical Trials of New Therapies for Conditions for which there are Known Effective Treatments.

Section 5: Priorities for Future Research.

15 The Research and Ethical Agenda.

Section 6: Conclusions and Future Directions.

16 Conclusions and Future Directions.

Appendix.

Index.