Much research in the philosophy of psychiatry has been devoted to the characterization of the normal and the pathological. In this article, we identify and deconstruct two postulates that have held sway in the philosophy of psychiatry. The first postulate concerns the belief that clinicians would benefit from conceiving of psychiatric disorders as stable entities with clear boundaries. By relying on a symptom-based approach, we support a conception of psychiatric disorders whose symptoms are the products of many activated mechanisms in (...) mutual interactions. The second postulate concerns the way in which the philosophy of psychiatry has approached the question of harm. We posit that clinicians perceive harms primarily through networks of clinical manifestations. The identification and deconstruction of these two postulates leads us to propose a practical definition of a psychiatric disorder that is useful for the clinician, while adopting a principle of prudential conservatism that does not exclude other theoretical definitions of psychiatric disorder that are useful as an epistemic hub. Thus, we propose the following definition of a psychiatric disorder that is relevant to clinical practice: “a set of clinical manifestations belonging to the prototypical central core of psychiatry, organized in a causal network, involving at least one harm, and whose set of harms exceeds the traditional threshold of significance for a given psychiatric disorder, directly related to an activated mechanism. Such a network composed of clinical manifestations is frozen in a state that is unable to allow the deactivation of these manifestations spontaneously without a therapeutic intervention”. (shrink)

This thesis is a philosophical examination of the explanatory roles of diagnoses in psychiatry. In medicine, diagnoses normally serve as causal explanations of patients’ symptoms. Given that psychiatry is a discipline whose practice is shaped by medical traditions, it is often implied that its diagnoses also serve such explanatory functions. This is evident in clinical texts that portray psychiatric diagnoses as referring to diseases that cause symptoms. However, there are problems which cast doubt on whether such portrayals are justified. I (...) address these problems and examine whether psychiatric diagnoses provide explanations of symptoms. The first problem is conceptual. In diagnostic manuals, psychiatric diagnoses are defined by their symptoms. This suggests that invoking them as explanations of the symptoms amounts to circularity. I argue that this can be resolved with an appropriate conceptual framework that captures the complex semantic values of diagnostic terms and their different uses in clinical discourse. I put forward such a framework based on two-dimensional semantics. The second problem is ontological. Empirical research suggests that diagnostic categories in psychiatry do not correspond to invariant causal types, but are associated with variable combinations of diverse causes that interact across biological, psychological, and social levels. Given this heterogeneity, I argue that psychiatric diagnoses fall short of paradigmatic cases of causal explanation, but that some can still provide other sorts of useful causal explanatory information. The original contribution of this thesis is the illumination of the conceptual relations between diagnoses and symptoms. This philosophical work is important, because it can be brought to valuable application in modifying psychiatric practice. (shrink)

A large part of our exploration of the world consists in categorizing or classifying the objects and processes we encounter, both in scientific and everyday contexts. There are various, perhaps innumerable, ways to sort objects into different kinds or categories, but it is commonly assumed that, among the countless possible types of classifications, one group is privileged. Philosophy refers to such categories as natural kinds. Standard examples of such kinds include fundamental physical particles, chemical elements, and biological species. The term (...) natural does not imply that natural kinds ought to categorize only naturally occurring stuff or objects. Candidates for natural kinds can include man-made substances, such as synthetic elements, that can be created in a laboratory. The naturalness in question is not the naturalness of the entities being classified, but that of the groupings themselves. Groupings that are artificial or arbitrary are not natural; they are invented or imposed on nature. Natural kinds, on the other hand, are not invented, and many assume that scientific investigations should discover them. (shrink)