Exploring the boundaries and ontology of Psychiatric Disorders (PDs) using the Homeostatic Property Cluster (HPC) model Marco Casali To cite this version: Marco Casali. Exploring the boundaries and ontology of Psychiatric Disorders (PDs) using the Home- ostatic Property Cluster (HPC) model. Lato Sensu, revue de la Société de philosophie des sciences, Société de philosophie des sciences, 2021, Théorie et données à l’heure des données massives. Actes du VIIe congrès de la Société de philosophie des sciences 8 (2), pp.15 - 31. 10.20416/LSRSPS.V8I2. hal-03214709 HAL Id: hal-03214709 https://hal.archives-ouvertes.fr/hal-03214709 Submitted on 2 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Vol 8 N°2 2021 DOI http://dx.doi.org/10.20416/LSRSPS.V8I2.3 Marco Casali EXPLORING THE BOUN- DARIES AND ONTOLOGY OF PSYCHIATRIC DISOR- DERS (PDS) USING THE HOMEOSTATIC PRO- PERTY CLUSTER (HPC) MODEL SOCIÉTÉ DE PHILOSOPHIE DES SCIENCES (SPS) École normale supérieure 45, rue d’Ulm 75005 Paris www.sps-philoscience.org Vol. 8 Marco Casali EXPLORING THE BOUNDARIES AND ONTOL- OGY OF PSYCHIATRIC DISORDERS (PDS) USING THE HOMEOSTATIC PROPERTY CLUSTER (HPC) MODEL In this article we show that, even though the classification and diagno- Sommaire sis of Psychiatric Disorders (PDs) are performed according to essential- ist terms, the psychiatric diagnoses currently employed, (i.e., clinical psychiatry) do not actually meet these criteria. Diagnosis is performed 1 – Introduction operationally. In this paper, we suggest a change of perspective. We re- 2 - Psychiatric practice: the continuous/discrete ject essentialism relating to PDs and argue for the Homeostatic Property problem and the operational synthesis Cluster (HPC) model, which allows a greater insight into the ontology of 3 - The operational synthesis is not an attempt PDs than the operational perspective. More specifically, we argue that the to further ontological exploration HPC model allows for a synthesis of continuous and discrete methods of understanding the boundaries between PDs. Finally, we specify in a more 3.1 - The positioning of our proposal within general manner, the kind of ontology we deal with when adopting the the existing literature in the philosophy of psychiatry HPC model, arguing that this model can be viewed as a mirror device, 4 - Our first proposal: linking the classical reflecting the ontological features of PDs. discrete/continuous debate with the HPC model 4.1. The HPC model of natural kinds 4.2 The extrapolation problem 4.3 The geometrical metaphor: the continuous and discrete synthesis within the HPC model Keywords : Psychiatric Disorders (PDs), Homeostatic Pro- 5. Our second proposal: the ontology perty Cluster (HPC), essentialism, operational synthesis, of HPC compared to PDs 6. Conclusions ontology. 1. Introduction the question of PDs’ boundaries synthesize discrete and con- tinuous systems. Within a spectrum of symptoms, they use This paper aims to propose a perspective that can improve a cut-point/cut-off to demarcate boundaries between disor- our ontological understanding of PDs. More specifically, the ders, and between the state of health and disordered health. aim of the present work is to address the two following points. We show that this synthesis is operational, namely, psychi- The first links two debates that are usually kept separate re- atrists define the boundaries of PDs according to the way in garding some practical and philosophical aspects of PDs. The which they are measured. On the other hand, regardless of second explores a novel ontology for PDs. their position on how PDs are framed, scholars of the sec- ond debate at least agree that the HPC model is ontological- This first point proposes linking two debates that are usually ly embedded. Indeed, this model was developed for the first considered distinct: 1) the debate within practical psychiatry time by Boyd (1988) while attempting to resolve ambiguities about the boundaries of PDs (e.g. are PDs discrete or continu- in the definition of species as natural kinds. In recent years, ous entities?; Bjelland et al. 2009; Broman-Fulks et al. 2010; the HPC model has been proposed as a tool for classifying Haslam 2003; Kasanin 1994; Keshavan et al. 2011; Muthén PDs. Our proposal underlines how the synthesis of discrete 2006; Ruscio, Haslam and Ruscio 2006; Shear et al. 2007; and continuous systems, used in clinical practice, is differ- Widiger and Samuel 2005); 2) and the philosophical debate ent from the synthesis (that we will propose) when working around how PDs are framed in the HPC model (Borsboom within the HPC model of natural kinds. Indeed, if in clini- 2008; Borsboom and Cramer 2013; Fried 2015; Kendler 2012 cal practice this synthesis is operational, we propose that in and Kendler, Zachar and Craver 2011). the HPC model, the synthesis is ontologically embedded. We propose a visualization of the synthesis between discrete and On the one hand, practical psychiatrists attempting to resolve continuous systems within the HPC model as substantiation. 15 N° 2 2021 Vol. 8 EXPLORING THE BOUNDARIES AND ONTO- LOGY OF PSYCHIATRIC DISORDERS (PDS) USING THE HOMEOSTATIC PROPERTY CLUSTER (HPC) MODEL Therefore, in this article, we aim to shift from an operational debate relating to PDs’ boundaries (i.e., discrete/continuous synthesis to a new, theoretical one. By “theoretical” we mean systems of classification) with the HPC model could be a pos- a synthesis that is in some sense embedded in ontology. Con- itive way of reframing that debate. In the final section, we ar- sidering a realist position, we believe that ontology could be gue for our second proposal, namely, in which sense can we useful in understanding, explaining and classifying PDs. infer more in relation to the ontology of PDs, using the HPC model. The second points explores this ontology. What does ontol- ogy mean for PDs in the context of the HPC framework? In the fields of philosophy of psychology, philosophy of psychi- atry and philosophy of mind, PDs are often conceived as on- 2. Psychiatric practice: the tologically “strange objects”. In the literature, there is some continuous/discrete prob- awareness that when dealing with PDs, naïve ideas of real- ism fail (Jablensky 2012, 2016; Kendell and Jablensky 2003; lem and the operational Kendler, Zachar and Craver 2011; Murphy 2015; Rodrigues and Banzato 2015; Schaffner 2012). Therefore, the majority synthesis of the debate in relation to PDs in terms of philosophy of psy- In mainstream psychiatric thought, PDs are most frequent- chiatry/psychology and mind could be summed up with the ly considered from an essentialist perspective (Adriaens and question: to what definition of reality do we have recourse De Block 2013; Deacon 2013; Haslam 2000; Wade and Hal- when we talk about PDs? This is difficult to answer because ligan 2004; Whitaker 2001, 2010). In general, an essential- essentialism, pragmatism (e.g., operational solutions) and ist thinker conceives PDs as having necessary and sufficient anti-psychiatrist positions1 are just around the corner. In re- properties. Most of the time, these properties are identified in lation to our specific topic, the question could be rephrased the brain as brain damage (e.g., brain lesions) or brain mod- as follows: what kind of ontology do we have when we frame ification (e.g., the famous example of the spirochete bacteri- PDs within the HPC model? To avoid falling into the afore- um, see Deacon (2013); Fried (2015); Kendler et al. (2011)).2 mentioned positions, we propose an exploration that at- One of the most historically important essentialist thinkers, tempts to define this kind of ontology. Emil Kraepelin (1856-1926), (for an overview see Jablensky (2012)), searched for lesions in his patients’ brains, in order Instead of continuing to follow etiological evidence, we wish to enucleate “disease entities” (Aragona 2015, p. 35).3 to shift attention to the robustness of clusters of symptoms. In broad terms, by “robustness” we mean clusters of symp- However, in clinical practice, psychiatrists do not actual- toms that repeat themselves several times among different ly embrace this perspective as it is affected by a number of patients. Our proposition is that the HPC model allows us to criticalities4. Among them, and one of the most controversial focus on this robustness. This alternative way of framing the questions at the heart of practical psychiatry, is whether PDs ontology of PDs is detached from traditional – and unsuc- are continuous or discrete entities. In this context, clinicians cessful – etiological evidence-seeking. are not essentialists. On the contrary, their solution is to syn- thetize discrete and continuous ideas about PDs in a practical The paper is organized as follows. In the second section we fashion, to make room for practical concerns (e.g., clinical describe the operational synthesis between the discrete and classification)5. To be exact: in a scenario in which there is a continuous perspectives of PDs in practical psychiatry. In the scale of continuous of symptoms/signs, clinicians operation- third section, we explore the reasons why that synthesis is not ally introduce cut-points/cut-offs that enable PDs to be un- ontologically informative. In the fourth section, we argue for derstood as discrete entities6. This discreetness is a necessary our first proposal, namely, the fact that linking the classical feature of clinical practice. This solution, that we will call op- 1.