Diseases, Functions, Values, and Psychiatric Classification

The philosophy of medicine and psychiatry has considered the defining of disease, illness, and disorder an important project for over three decades. Within this literature, accounts based on adaptive "functions" have been prominent, particularly in the DSM nosology. In response to this trend, Jerome Wakefield has presented a view of mental disorder as "harmful dysfunction." In this view, "harm" contributes the value-element to disorder concepts, while "dysfunction" implies a value-free foundation as long as the latter is grounded in evolutionary biology. In a critical review of Wakefield's and others' functionalist arguments for disorder concepts, we make four major points: (1) functionalists fail to define function and dysfunction independent of value terms; (2) Wakefield's (in particular) view of evolutionary biology neglects the goal-directed and evaluational nature of teleological concepts; (3) even if the grounding of the dysfunction concept is accepted as value-free, this particular effort yields no practical application for contemporary psychiatric nosology; and (4) Wakefield's project assumes an ethical subjectivism that cannot sustain its value-neutral aspirations. In conclusion, we discuss the implications of our critique for psychiatric classification. We recommend a shift away from the definition of value-free disorder concepts, instead emphasizing the analysis of the logical features and the value commitments in nosological categories.