- Do People Defy Generalizations?Examining the Case Against Evidence-Based Medicine in Psychiatry
Philosophy, psychiatry, action, content
Evidence-based medicine (EBM) in psychiatry presupposes that it is possible to track the causal efficacy of treatments for psychopathological conditions using scientific methods. One central aim of EBM is to ascertain the causally efficacious component of the treatment of a given condition. This is done by collecting data from randomized control trials, where this data are of groups rather than of individuals (Bolton, 2008).
EBM is felt by many to have significant limitations when applied in the field of psychiatric medicine, and these limitations are thought to arise owing to a particular fact about psychiatry, namely that the subject of psychiatry is the human person. For brevity, I will refer to this broad claim as the Unsuitability Intuition (UI), which can be stated as follows:
The UI is the intuition that EBM is somehow unsuitable for dealing with people.
The aims of this paper are twofold. First, I try to pinpoint the source(s) of anxiety about EBM, and therein to clarify the exact sense(s) in which EBM might be said to be unsuitable or problematic. Second, I evaluate the validity of these concerns, focusing on two broad interrelated questions: (1) Is it actually something about human persons that creates trouble for EBM in psychiatry, and if so, what is the nature of this trouble?; and (2) What assumptions about EBM are made such that EBM is problematic in light of the fact that the subject of psychiatry is the human person?
As an empirical point, EBM in psychiatry is applied to two methods of treatment: psychotropic drugs, and more recently, cognitive–behavioral therapies. Each of these throws up slightly different issues in light of the two questions just identified. To accommodate relevant differences, I structure this paper as follows. Bearing in mind that the overall aim of the paper is to scrutinize the intuition that EBM is somehow unsuitable for dealing with people, I begin by exploring one common suggestion as to what underpins this intuition: The problem we are confronted with, in applying EBM to people, is the problem of applying generalizations to particular instances (Wifstad 2008). To anticipate, I argue that this worry concerns a problem that, in fact, applies to the scientific method in general. That is, it is not a [End Page 167] problem arising specifically from the fact that the subject of psychiatry is the human person. So if this is the worry about EBM, then as it stands, it does not satisfactorily explain the intuition that EBM is somehow unsuitable for dealing with people.
Against this, the UI theorist might defend his intuition by attempting to specify the reasons why persons, unlike physical material, present a special challenge to the scientific method presupposed by EBM. One way of doing this is to point out that the determinants of human behavior cannot be captured by generalizations (and in particular, by causal generalizations). There are two ways of worrying about EBM here: On the first, the problem of EBM in psychiatry is a pragmatic worry that arises in view of the complexity of the determinants of human behavior and the limited capacity for observation. If this is the worry, though, it can be overcome to a greater or lesser extent within psychiatric practice. The second worry consists in the thought that humans pose a constitutive problem for EBM in psychiatry. However, I argue that this worry turns out to rest on assumptions about human behavior that are not unproblematic in themselves. Thus, UI is underpinned either by a pragmatic worry that can be overcome to some extent, or else it is underpinned by certain assumptions that are problematic, if not altogether wrong. This means that UI cannot be founded on a constitutive point about persons—at least, it does not seem to be, if it arises from a concern about applying generalizations to individual human beings.
But there is a very different type of worry that might underpin UI, one that does not issue from considerations about the relation between the general and the particular. UI theorists could be worried about specific...