Mental Disorders As Dispositions

Simon Keller (Victoria University of Wellington)

Mental disorders are diagnosed using checklists of symptoms, not by identifying conditions that explain symptoms. That is widely regarded as an embarrassment for psychiatry. Defenders of psychiatry often set out to find the entities that lie behind mental symptoms: perhaps cognitive dysfunctions or neural states.  Anti-psychiatrists often use diagnostic practices to argue that the very idea of mental disorder should be abandoned. Some theorists take an in-between approach, arguing that mental disorders just are networks of mutually reinforcing symptoms. This “Symptom Network Theory” is subject to several objections, but it can be improved if we conceive of mental disorders not as networks of symptoms, but rather as dispositions to display symptoms.

Applying David Lewis’s analysis of dispositions, which allows dispositions to be “finkish” or “masked”, a dispositional account of mental disorder can allow a person to display the symptoms of a disorder without having that disorder, or to have a disorder without displaying its symptoms. A dispositional theory can maintain the conceptual gap between mental disorders and their symptoms without denying the existence of mental disorder, and without relying on too ambitious an analogy with physical disorder.