The Placebo Effect: Can Psychoanalytic Theory Help Explain the Phenomenon?

Introduction

In the late 1970s and early 1980s, Adolf Grünbaum's (1977; 1981; 1982) critique of psychoanalysis as a science was hotly contested (Edelson 1984). Although not claiming that psychoanalysis was ineffective, Grünbaum held that its successes were attributable to suggestion and the placebo effect—that is, to nonspecific treatment measures—rather than to the causal effect of psychoanalytic treatment. Grünbaum's basic challenge to psychoanalysis as a scientific discipline held that (1) psychoanalysis as a treatment was centrally predicated upon overcoming repression such that patient and analyst would agree on the contents uncovered—the so-called "tally argument"; and (2) that the data generated in the process of psychoanalysis could not be probative as these were (a) contaminated by suggestion, and (b) not subject to scientific test as the data were enumeratively inductive (i.e., here is another example bearing out X hypothesis) rather than eliminatively inductive (i.e., this result shows that X hypothesis cannot be correct, but Y hypothesis still stands).

There are two different sorts of answers to Grünbaum. As to his first claim, few contemporary psychoanalytic theorists hold that the central task in psychoanalysis is overcoming repression such that patient and analyst agree upon the reconstructed contents. To the extent that this aim is not central to psychoanalysis, the attempt to use the tally argument against psychoanalysis rests on a faulty premise. Regarding the second claim, although in my view Grünbaum is correct that data presuming the assumptions (or hypotheses) under test cannot provide evidence for those assumptions, it is quite possible to conduct research on the assumptions of psychoanalysis with data outside the psychoanalytic situation, data that can be probative regarding these assumptions.¹

And yet, twenty years after these debates, Grünbaum's critique has stimulated much that is of interest. For example, the question of the role of the placebo effect in psychoanalysis can hardly be said to be resolved. But here there is the larger puzzle: the role of the placebo effect in psychoanalysis is unresolved because the nature of the placebo effect—its psychological mechanisms—is itself unresolved. Thus, the purpose of this paper: I shall argue that, regardless of the role placebos play in successful psychoanalyses, psychoanalytic theory can help explain the psychological operations underlying placebo effects.

General Findings and Explanations

In a typical type of testing for new drugs or procedures, double blind studies are conducted such that one group of randomly assigned subjects gets the active agent under test; another group gets an older reliable active agent; and a third group gets a placebo drug, with neither subjects nor experimenters knowing which group gets which treatment. In the best studies, not only does the placebo treatment have side-effects like those of the active drug (so-called "active-placebos"), but there is a fourth group in the study whose members are monitored but get no treatment at all.² This is important because improvement may be due to (a) regression to the mean of intensity of symptoms, and (b) the natural course of a symptom over time, rather than owing to the active agent or the placebo.

Findings over many decades, in hundreds of experiments, on many types of ailments have shown that around one-third of subjects receiving placebo treatments show some improvement (Hrobjartsson and Gotzche 2001, 1594). And over these decades several different hypotheses concerning the mechanisms for the placebo response have been proposed (Shapiro and Morris 1978; Kirsch 2004; and Stewart-Williams and Podd 2004).

One of the first explanations proposed was that those who did well on placebos had more suggestible personalities (Beecher 1955). Although this is a plausible hypothesis, several subsequent studies (reviewed in Shapiro and Morris 1978, 374–76) demonstrated that placebo effects varied quite independently of personality types, with suggestible subjects showing no increased placebo effect overall.

Conscious expectancy has also been offered as an explanation. There have been many experiments showing that conscious expectation regarding an improvement with treatment does have a pronounced effect on outcome (see Stewart-Williams and Podd 2004 for references...