John Kelley Professor of Psychology, Endicott College, Beverly, and Harvard Medical School, Boston, USA
Lumping and Splitting: Toward a Taxonomy of Placebo and Related Effects
The placebo effect is closely related to many other constructs, including most prominently, conditioning and expectancy, but also natural history, regression to the mean, priming, mindset, context effects, the meaning response, specific and non-specific clinical effects, placebo-related effects, the patient-clinician relationship, and the common factors in psychotherapy. How are these various constructs related to one another? To what degree do they overlap, and to what degree do they diverge? To form a better theoretical understanding of these constructs and to foster improved empirical research, is it better to lump these constructs together in some fashion? Or will progress best be served by maintaining the splits between the constructs? Or would it perhaps be most effective to employ some mixture of lumping and splitting? In this talk, I will address these and related questions with two major goals: (1) to delineate and clarify the relationship between these constructs; and (2) to suggest some possible re-alignments in the way in which we conceptualize the relationships among these constructs that might prove useful in fostering research on placebo and related effects. In addition, clarifying the interconnections between the placebo effect and other related constructs has the potential to spark innovative cross-fertilizations between related areas of research.
John M. Kelley, Ph.D. is Professor of Psychology at Endicott College and the Deputy Director of the Program in Placebo Studies and the Therapeutic Encounter at Harvard Medical School. In addition, he is a licensed psychologist in the Psychiatry Service at Massachusetts General Hospital, and he has a private practice in psychotherapy. His research interests include: (1) investigating the placebo effect in medical and psychiatric disorders, and (2) understanding how the patient-clinician relationship affects healthcare outcomes in medicine and psychiatry. Professor Kelley has served on ten US National Institutes of Health (NIH) research grants. His research has also been funded by the Robert Wood Johnson Foundation, the Arnold P. Gold Foundation, the David Judah Fund, the Josiah Macy, Jr. Foundation, and the Risk Management Foundation.