Towards an Ontology of Pain

We present an ontology of pain and of other pain-related phenomena, building on the definition of pain provided by the International Association for the Study of Pain (IASP). Our strategy is to identify an evolutionarily basic canonical pain phenomenon, involving unpleasant sensory and emotional experience based causally in localized tissue damage that is concordant with that experience. We then show how different variant cases of this canonical pain phenomenon can be distinguished, including pain that is elevated relative to peripheral trauma, pain that is caused neuropathically (thus with no necessary peripheral stimulus), and pain reports arising through deception either of self or of others. We describe how our approach can answer some of the objections raised against the IASP definition, and sketch how it can be used to support more sophisticated discrimination of different types of pain resulting in improved data analysis that can help in advancing pain research. 1 Background: The Physical Basis of Disease Increasingly, ontologies are being used to support the retrieval, integration and analysis of a variety of different kinds of biomedical data. Ontology-based technology has been successful especially in support of data-driven research in the basic biological sciences and in model organism studies, and efforts are now being made to extend these successes to the domain of human disease and diagnosis. The most successful ontologies, above all the Gene Ontology [Bodenreider 2008], rest on objective classifications of biological phenomena primarily at the molecular and cellular levels, and we face difficulties in applying the same approach where we are dealing with clinical data pertaining to pain and to other symptoms of human disease marked by the feature of subjectivity. The goal of this communication is to provide the beginnings of an ontological account of pain and of those phenomena closely related to pain that are commonly described as pain in patient reports. Because pain has subtly complex characteristics, we believe that its examination will have heuristic value for ontological accounts of symptoms (such as feelings of nausea, fatigue, depression) more generally.