Placebo. Historie, biologi og effekt

Since 1950 or so, placebos and their effect have generated a considerable interest in certain medical communities, in particular among psychiatrists and the designers of clinical trials, yet the only significant external study of this phenomenon to appear has been Howard Brody's doctoral investigation, Placebos and the philosophy ofmedicine, published in 1980. In 1997, however, three book-length studies were produced: a collection of essays edited by Anne Harrington (The placebo effect: an interdisciplinary exploration, Harvard University Press); Arthur and Elaine Shapiro's The powerful placebo (Johns Hopkins University Press), and this multi-authored Danish contribution; testimony, perhaps, to the recent revival of interest in mind-body relationships, in the power of the mind to influence healing. The Harrington volume is philosophical in its approach, being intended "to push the envelope of thinking on placebo in ways that might help reshape how the problem is conceived and studied ... to ponder how to do better justice to the integrated ways in which sociocultural meanings and physiological mechanisms function fluidly within a single human being" (p. 9). It relates largely to current concerns over placebos, whereas the Shapiros elegantly and accessibly take a long-term historical perspective, from Cro-Magnon times (c. 20,000 BC) forward to the end of the twentieth century. The Shapiro emphasis is, essentially, on the centrality of the placebo effect in the success of medical intervention across the centuries; in the relations of the placebo to psychiatry and to clinical trials; in the laws which govern the nonspecific but very powerful therapeutic potential of the placebo effect. Arthur Shapiro himself, who died in 1995, may be considered the doyen of placebo studies: his contributions far outnumber other entries in his own bibliography, and provide crucial core literature for the independent Danish investigations. Three publications on this subject in one year might be considered at least one too many, but the Danes' study is by no means superfluous. It at once complements and extends the perspective offered by the other two books. Like the Shapiro volume, it is lucidly and accessibly written for a nonspecialist readership; unlike the Shapiro volume, it consciously takes three different approaches to its subject. In the first section, Asbj0rn Hr6bjartsson explores current issues surrounding the placebo effect. The placebo, he argues, provides a unique focus for examining the relationship between medical science, body, mind, and clinical treatment. In the first place he examines the diverse and often paradoxical uses of the placebo concept in medical literature (for example, that it is at once accepted as scientific good in clinical experiment yet utilized as an expression of doubt, or as an implication of pseudo-science, when used of complementary therapies), then he discusses selected definitions of the terms "placebo" and "placebo effect". The third section deals with the transformation of the placebo effect, from a part of everyday medicine before World War II, to a new central role in the randomized clinical trial after that War. It is an area dealt with more fully and reliably by the Shapiros, but it is good to be reminded, by the account of Johannes Fibiger's pioneering application of Louis' numerical method in his 1898 investigations in Copenhagen into the effectiveness of diphtheria anti-toxin (p. 33), that serious medical research is undertaken in countries other than the big four (Britain, America, France and Germany). Hr6bjartsson concludes by discussing how to measure the placebo effect, and its significance in clinical medicine. The central section of the book, by Lars Ole Andersen, deals with the placebo's historical