In the last forty years there have been many attempts to provide a general and useful definition of the concept of “mental disorder”. Most of these attempts have in common some general methodological precept: they rely on conceptual analysis, which aims at clarifying the uses of a concept – whether in ordinary language or a scientific vocabulary – in order to get to a clearer understanding of it. In this chapter we question the appropriateness and relevance of this method in its application to the domain of mental health.

In the first part of the chapter, we draw attention to the philosophical presuppositions that underlie some applications of conceptual analysis. As we shall see, certain authors have sought to use conceptual analysis in diverse ways; we argue that some uses have been misguided. This philosophical enquiry has proved to be important in the psychiatric context, since the main issue regarding classifications of mental disorders revolves around what should be included as a mental disorder (one of the most striking historical examples, discussed below, is homosexuality). How are such decisions taken and how should they be made? Who has the authority to decide what should fall under the concept of mental disorder, and based on what criteria? To what extent can the philosophy of language help solve such issues?