As it emerged from philosophical analyses and cognitive research, most concepts exhibit typicality effects, and resist to the efforts of defining them in terms of necessary and sufficient conditions. This holds also in the case of many medical concepts. This is a problem for the design of computer science ontologies, since knowledge representation formalisms commonly adopted in this field (such as, in the first place, the Web Ontology Language - OWL) do not allow for the representation of concepts in terms (...) of typical traits. The need of representing concepts in terms of typical traits concerns almost every domain of real world knowledge, including medical domains. In particular, in this article we take into account the domain of mental disorders, starting from the DSM-5 descriptions of some specific disorders. We favour a hybrid approach to concept representation, in which ontology oriented formalisms are combined to a geometric representation of knowledge based on conceptual space. As a preliminary step to apply our proposal to mental disorder concepts, we started to develop an OWL ontology of the schizophrenia spectrum, which is as close as possible to the DSM-5 descriptions. (shrink)

As it emerged from philosophical analyses and cognitive research, most concepts exhibit typicality effects, and resist to the efforts of defining them in terms of necessary and sufficient conditions. This holds also in the case of many medical concepts. This is a problem for the design of computer science ontologies, since knowledge representation formalisms commonly adopted in this field do not allow for the representation of concepts in terms of typical traits. However, the need of representing concepts in terms of (...) typical traits concerns almost every domain of real world knowledge, including medical domains. In particular, in this article we take into account the domain of mental disorders, starting from the DSM-5 descriptions of some specific mental disorders. On this respect, we favor a hybrid approach to the representation of psychiatric concepts, in which ontology oriented formalisms are combined to a geometric representation of knowledge based on conceptual spaces. (shrink)

Recently, concerns have been raised about the phenomenon of ‘overdiagnosis’, the diagnosis of a condition that is not causing harm, and will not come to cause harm. Along with practical, ethical, and scientific questions, overdiagnosis raises questions about our concept of disease. In this paper, we analyse overdiagnosis as an epistemic problem and show how it challenges many existing accounts of disease. In particular, it raises ques- tions about conceptual links drawn between disease and dysfunction, harm, and risk. We argue (...) that ‘disease’ should be considered a vague concept with a non-classical structure. On this view, overdiagnosed cases are ‘borderline’ cases of disease, falling in the zone between cases that are clearly disease, and cases that are clearly not disease. We then develop a pre ́cising definition of disease designed to provide practical help in preventing and limiting overdiagnosis. We argue that for this purpose, we can define disease as dysfunction that has a significant risk of causing severe harm to the patient. (shrink)

In this paper, we examine recent critiques of the debate about defining disease, which claim that its use of conceptual analysis embeds the problematic assumption that the concept is classically structured. These critiques suggest, instead, developing plural stipulative definitions. Although we substantially agree with these critiques, we resist their implication that no general definition of “disease” is possible. We offer an alternative, inductive argument that disease cannot be classically defined and that the best explanation for this is that the concept (...) is structured as a cluster. We further argue that we do not need to reject the possibility of defining the general concept “disease” to legitimate developing stipulative definitions of disease that are relative to particular purposes. A cluster definition of disease is compatible with contextually motivated definitions, which may be considered précisifications of the more general cluster concept. (shrink)

Biological dysfunction is regarded, in many accounts, as necessary and perhaps sufficient for disease. But although disease is conceptualized as all-or-nothing, biological functions often differ by degree. A tension is created by attempting to use a continuous variable as the basis for a categorical definition, raising questions about how we are to pinpoint the boundary between health and disease. This is the line-drawing problem. In this paper, we show how the line-drawing problem arises within “dysfunction-requiring” accounts of disease, such as (...) those of Christopher Boorse and Jerome Wakefield. We then provide several detailed examples to establish that biological dysfunction cannot provide a boundary. We examine potential ways of resolving the line-drawing problem, either by dropping one of the claims that generates it, or by appealing to additional criteria. We argue that two of these options are plausible, and that each of these can be applied with regard to different diseases. (shrink)

It is commonly thought that mental disorder is a valid concept only in so far as it is an extension of or continuous with the concept of physical disorder. A valid extension has to meet two criteria: determination and coherence. Essentialists meet these criteria through necessary and sufficient conditions for being a disorder. Two Wittgensteinian alternatives to essentialism are considered and assessed against the two criteria. These are the family resemblance approach and the secondary sense approach. Where the focus is (...) solely on the characteristics or attributes of things, both these approaches seem to fail to meet the criteria for valid extension. However, this focus on attributes is mistaken. The criteria for valid extension are met in the case of family resemblance by the pattern of characteristics associated with a concept, and by the limits of intelligibility of applying a concept. Secondary sense, though it may have some claims to be a good account of the relation between physical and mental disorder, cannot claim to meet the two criteria of valid extension. (shrink)

Overdiagnosis and disease are related concepts. Widened conceptions of disease increase overdiagnosis and vice versa. This is partly because there is a close and complex relationship between disease and overdiagnosis. In order to address the problems with overdiagnosis, we may benefit from a closer understanding this relationship. Accordingly, the objective of this article is to elucidate the relationship between disease and overdiagnosis. To do so, the article starts with scrutinizing how overdiagnosis can explain the expansion of the concept of disease. (...) Then it investigates how definitions of disease address various challenges of overdiagnosis. The article specifically investigates recent attempts to clarify the relationship between the concepts of disease and overdiagnosis. Several shortcomings are identified and lead to a closer analysis of overdiagnosis in the diagnostic process. Contrary to recent contributions to the field, it is argued that cases of overdiagnosis are not cases of disease. They are non-verified labelling of disease. It is revealed how overdiagnosis establishes an unwarranted link between indicative phenomena, such as polyps or cell changes, and harm, and thereby generates a link to disease. One implication of this study is that we should stop attributing disease language to indicative phenomena. That is, we should stop calling it “cancer screening” when we are actually searching for polyps. Another implications is that we should strive for scientific progress in differentiating phenomena that are of negative value to us from those that are not. In overdiagnosis we diagnose something that is not disease: it is over-diagnosis. (shrink)

Health and disease are core concepts in health care and have attracted substantial interest and controversy. In recent and interesting contributions to the debate it has been argued that the challenges with the concept of disease can be resolved by a prototype concept of disease. As a robin is a more prototypical of a bird than a penguin, some diseases are more prototypical than others. If disease is a prototype concept, it would change nosology, but also health care and the (...) study of health and disease. However, the statement that “disease is a prototype concept” forms an empirically testable hypothesis. Therefore, this study aims to test the hypothesis that health professionals have a prototype concept of disease. Two hundred twenty-three health care professionals in Norway were invited to participate in a survey where they were asked to rank a wide range of diseases according to how typical they considered them to be as diseases. Results were analysed with descriptive statistics. The response rate was 90%. Lung cancer, leukemia, colon cancer, myocardial infarction, and AIDS are the diseases ranged to be most typical, while homosexuality, pregnancy, drapetomania, dissidence, and nostalgia are considered to be the least typical diseases. The results also show that the answers to how typical various diseases are vary greatly, even amongst a relatively homogenous group of health professionals. This study falsifies the hypothesis that disease is a prototype concept for health professionals. This has implications for the debate on core concepts for health care. If health professionals do not have a prototype concept of disease, it is unlikely that there is a prototype concept of disease in general. Consequently, nosologies should not be based on prototypes. (shrink)

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)

The nosological diagnosis is a particular type of nontheoretical diagnosis consisting of identifying the disease that afflicts the patient without explaining the underlying etiopathological mechanisms. Its origins are within the essentialist point of view on the nature of diseases, which dates back at least to 18th-century taxonomy studies. In this article, we propose a model of nosological diagnosis as a two-phase process composed of the categorization of inductive inferences and argumentations by analogy. In the inductive phase, disease entities are identified (...) by means of typicality-based categorization processes, and meaningful clinical samples are learned ; in the subsequent phase, those samples are used as the bases of argumentations by analogy to obtain a diagnosis for a given patient. This model extends the prototype resemblance theory of disease including also the exemplar theory proposed in cognitive science and, moreover, it frames the clinical activity of nosological diagnosis and how it can be explained within the theory of argumentation. According to it, diagnosis based on the recognition of a typical syndrome is explained in terms of the prototype theory of categorization and the antisymmetrical argumentation by analogy, while diagnosis based on a comparison with a previous clinical case is explained by the exemplar theory of categorization and by the symmetrical argumentation by analogy. (shrink)

In the present paper, we shall discuss the notion of prototype and show its benefits. First, we shall argue that the prototypes of common-sense concepts are necessary for making prompt and reliable categorisations and inferences. However, the features constituting the prototype of a particular concept are neither necessary nor sufficient conditions for determining category membership; in this sense, the prototype might lead to conclusions regarded as wrong from a theoretical perspective. That being said, the prototype remains essential to handling most (...) ordinary situations and helps us to perform important cognitive tasks. To exemplify this point, we shall focus on disease concepts. Our analysis concludes that the prototypical conception of disease is needed to make important inferences from a practical and clinical point of view. Moreover, it can still be compatible with a classical definition of disease, given in terms of necessary and sufficient conditions. In the first section, we shall compare the notion of stereotype, as it has been introduced in philosophy of language by Hilary Putnam, with the notion of prototype, as it has been developed in the cognitive sciences. In the second section, we shall discuss the general role of prototypical information in cognition and stress its centrality. In the third section, we shall apply our previous discussion to the specific case of medical concepts, before briefly summarising our conclusions in section four. (shrink)

Come è emerso dall’analisi filosofica e dalla ricerca nelle scienze cogni- tive, la maggior parte dei concetti, tra cui molti concetti medici, esibisce degli “effetti prototipici” e non riesce ad essere definita nei termini di condizioni necessarie e sufficienti. Questo aspetto rappresenta un problema per la pro- gettazione di ontologie in informatica, poiché i formalismi adottati per la rap- presentazione della conoscenza (a partire da OWL – Web Ontology Langua- ge) non sono in grado di rendere conto dei concetti nei (...) termini dei loro tratti prototipici. Nel presente articolo ci concentriamo sulla classe dei disordini mentali facendo riferimento alle descrizioni che ne vengono date nel DSM-5. L’idea è quella di proporre un approccio ibrido, in cui i formalismi delle ontologie sono combinati a una rappresentazione geometrica della conoscenza basata sugli spazi concettuali. (shrink)