Cultural psychiatry on Wakefield's procrustean bed

Jerome Wakefield has advanced an account of mental disorder that aims to provide a way to distinguish bona fide psychiatric disorders from "problems in living". He claims that it is possible to strip away the normative component of a disorder to leave a notion of dysfunction that is a "purely factual scientific concept". According to Wakefield's harmful dysfunction analysis, something is a mental disorder if, and only if, there is a deviation from natural function and that deviation is harmful. Natural function is construed as the function selected for by evolution. We offer four reasons for doubting that natural function can be determined by an application of evolutionary theory and, thus, for doubting the validity of the harmful dysfunction analysis.

First, the boundary between function and dysfunction is indeterminate. Although some traits or states show points of rarity or abrupt transitions, in many instances, psychological function and dysfunction manifest as a spectrum. Some people are more naturally anxious than others, for example. How far away from statistical normality does a function have to be to count as dysfunction? It is hard to see how to answer this question without appealing to a notion of deviation that is harmful or undesirable. And, indeed, notions of mental disorder in many cultures are closely tied to inappropriate or problematic social behavior, not to notions of internal (psychological or physiological) functioning (1,2). This way of understanding dysfunction, however, collapses the putatively factual component of the harmful dysfunction analysis into the normative one.

Second, natural function may not be actual function. The existence of many traits may be explained not by the increased fitness they confer but by evolutionary conservatism. A trait may be present in a species because it was present in the evolutionary ancestors of the species and was conserved because it was harmless or intrinsic to developmental pathways (3). Similarly, some physical and psychological human traits may best be explained by the fact that they conferred some adaptive advantage on an evolutionary ancestor of ours rather than on us. The natural function of a system, in Wakefield's sense, may have little to do with its current function.

Third, natural brain function may not be actual brain function. Neural plasticity makes a divergence between natural and actual function particularly likely in psychiatric disorder. In most human beings, for example, primary visual cortex functions to extract information about the external world from light. But in people who have lost their sight (and are naïve to Braille), primary visual cortex becomes responsive to tactile information (4). The function of primary visual cortex, it seems, has more to do with input than with selection pressures. Were a virus to render all human beings blind, the actual function of primary visual cortex would ipso facto be tactile, and disorders of primary visual cortex would have nothing to do with the function for which it was selected. While the example is extreme, it points up the fact that brain function depends significantly on environment.

Fourth, mental function and dysfunction are essentially dependent on culture. Could an early hominid have had attention deficit/hyperactivity disorder (ADHD)? That depends on the tasks for which attention is required. The ability to sit still for long hours in a classroom is a significant part of what we now count as normal attention. Since no such demand was placed on the early hominid child, he could have had normal attention even if his attention functions were, biologically speaking, identical to a child with ADHD. Note that this is not a case of the hominid child having a harmless dysfunction. To say that would be to beg the question of what a dysfunction is. Rather, the concept of normal mental function varies in part with the demands placed by culture on the mind. It cannot be determined by evolutionary theory alone.

As Wakefield notes, culture exerts profound effects on symptom experience and expression in ways that may make symptom-based diagnostic criteria difficult to apply (5). But culture may go well beyond this to influence the mechanisms of psychiatric disorders. For example, in Cambodia, dizziness can indicate a "wind" attack, a potentially serious illness (6). The orthostatic dizziness that sometimes follows standing up can therefore lead to panic in a Cambodian. A Canadian whose mental functions were identical might never suffer from panic attacks because he fails to have the relevant beliefs. What makes the Cambodian, but not the Canadian, disordered depends upon culture. Again, it would be misleading to claim that the Canadian has the same dysfunction as the Cambodian but that it is only harmful in Cambodia. The specific dysfunction depends essentially on task demands that, in turn, depend on culture.

Psychiatry is a young discipline. Wakefield is asking it to lie on a procrustean bed and lose the limbs that do not sit well with an evolutionary conception of dysfunction. But there is no reason why psychiatry should be shrunk to fit and no reason to restrict it at a time when we understand so little about mental disorder. We should rather enlarge its domain of theory and practice to understand developmental problems in both an evolutionary and a social context. In response to Wakefield's worry that without something like harmful dysfunction analysis we will have no way to critique diagnostic constructs and criteria, we suggest that an alternative "place to stand" is on an integrated conception of mental function that is responsive to a range of considerations, from evolutionary theory and neurobiology, through cultural context, to systematic analyses of the social functions of the diagnostic construct itself.