Foundations for a realist ontology of mental disease

Abstract

While classifications of mental disorders have existed for over one hundred years, it still remains unspecified what terms such as 'mental disorder', 'disease' and 'illness' might actually denote. While ontologies have been called in aid to address this shortfall since the GALEN project of the early 1990s, most attempts thus far have sought to provide a formal description of the structure of some pre-existing terminology or classification, rather than of the corresponding structures and processes on the side of the patient.We here present a view of mental disease that is based on ontological realism and which follows the principles embodied in Basic Formal Ontology (BFO) and in the application of BFO in the Ontology of General Medical Science (OGMS). We analyzed statements about what counts as a mental disease provided (1) in the research agenda for the DSM-V, and (2) in Pies' model. The results were used to assess whether the representational units of BFO and OGMS were adequate as foundations for a formal representation of the entities in reality that these statements attempt to describe. We then analyzed the representational units specific to mental disease and provided corresponding definitions.Our key contributions lie in the identification of confusions and conflations in the existing terminology of mental disease and in providing what we believe is a framework for the sort of clear and unambiguous reference to entities on the side of the patient that is needed in order to avoid these confusions in the future.

Figure 1

Ontological relations involving disease and bearer of disease

Figure 2

Foundational entities for an ontology of mental disease. Shape coding: terms in squared boxes are from feeder ontologies such as BFO and OGMS; terms in rounded boxes are specific to the Ontology of Mental Disease. Color coding: L1 continuants (first order entities) are depicted in yellow, L2/L3 continuants (representations) in orange; processes are depicted in green, abbreviations for disjunctions are in light blue. Red, unlabeled arrows indicate subsumption; black arrows are labeled according to the relation they depict, the label being either under or right from the arrows. Some obvious relationships have been left out to keep the figure intelligible.