Philosophy of Psychiatry: A New Sweeping Review for Psychiatric Clinicians

Stein et al. (2024) in World Psychiatry

Allow me to highlight a forum article, Philosophy of psychiatry: theoretical advances and clinical implications, in the June 2024 issue of World Psychiatry, with myself as the last author. It’s a review of a broad range of conceptual debates and developments aimed at psychiatric clinicians and educators, with a focus on issues such as the nature of disorder judgments, psychiatric classification, explanatory pluralism, and embodied cognition. The publication of this article is a mini-milestone for me as an academic psychiatrist, but it’s also encouraging to see a top psychiatric journal featuring work related to philosophy of psychiatry and devoting extensive discussion to it. The project was led by Dan Stein, and it was an honor working with this brilliant team of authors (many of whom I have the fortune to call good friends) that includes both rising stars as well as distinguished veterans: Kris Nielsen, Anna Hartford, Anne-Marie Gagné-Julien, Shane Glackin, Karl Friston, Mario Maj, Peter Zachar.¹ The article is accompanied by an editorial by Ken Kendler (someone I deeply admire) and commentaries by various prominent psychiatrists and philosophers (Miriam Solomon, Damiaan Denys, Steven E. Hyman, John Z. Sadler, Bill Fulford, Matthew R. Broome, Derek Bolton, and Manfred Spitzer).

The article and commentaries are open-access. Please check them out. If you work with psychiatric trainees, consider using them as a resource. (If you prefer, you can access the whole issue as a single pdf here.)

To give you a taste of the discussion, I am posting some excerpts from the article below. (For ease of reading, I’ve removed reference numbers from the text.)

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Psychiatric classification: tackling essentialism

“Once we have implicitly or explicitly identified a class of mental disorders, a set of psychopathological states, or a community of psychiatric conditions/mental health problems, we can further ask: How do we map the territory of psychopathology? How do we distinguish between conditions within the class of mental disorders? How do we demarcate disorder from normality?

Philosophy of psychiatry has been helpful in clarifying the metaphysical and methodological assumptions that guide the search for answers to these questions. One common metaphysical assumption in psychiatric classification has been essentialism. This is the notion that categories have essences, identity-determining properties that all members have in common and that distinguish them from members of other categories. Kinds with essences have been called natural kinds, meaning that they reflect the structure of the natural world. In the context of psychopathology, an essentialist view implies that psychiatric disease entities are discovered through scientific inquiry, similar to the identification of infectious disease entities in medicine, and thus a valid psychiatric classification “carves nature at its joints”, as Plato put it.

Philosophy of biology and of psychology have recently focused on how causal processes and mechanisms undergird observed phenomena. When these processes and mechanisms are well understood, professionals are often able to use them as the basis for classification. This is the case for infectious diseases, in which classification based on identification of the causative pathogen is possible. However, when the processes and mechanisms of an illness are particularly complex, dimensional or multifactorial, knowledge of etiology by itself does not necessarily offer an optimal classification, and we rely on additional considerations – on what we want the classification to accomplish – to draw boundaries and set thresholds. This applies to many areas of medicine, but is an issue that is more pervasive and pronounced in psychiatry.

From a somewhat simplified metaphysical perspective, we may think of a classification as demarcating natural kinds, practical kinds, or social kinds. If psychiatric classifications such as the DSM and the ICD were demarcating natural kinds, we would expect each diagnosis to correspond to an entity that exists in the structure of the world, independent of human interests. E. Kraepelin, for instance, believed in the existence of natural disease entities in psychiatry, and in addition held the view that pathological anatomy, etiology, and clinical symptomatology including course of illness, would all coincide in the case of such entities.

The assumption that there are natural disease entities in psychiatry was also adopted by the neo-Kraepelinians, and implicitly guided the development of the DSM-III. Furthermore, the Kraepelinian notion of convergence of validators was also accepted by Robins and Guze, who assumed that their proposed validators of clinical description, laboratory findings, course of illness, and family studies would all point towards the same disease entities. This set the agenda for a research program for the next several decades in which researchers sought to validate the DSM diagnostic constructs.

By the 1990s, however, there was growing recognition that different validators might not inevitably align to offer a single privileged classification, in a way that amounts to a psychiatric version of the periodic table of elements. Rather, different validators suggest alternative mappings of the space of psychopathology. For example, in the study of schizophrenia, shared family history suggests a broad mapping (schizophrenia spectrum), whereas poor outcome indicates a narrower mapping (schizophrenia). In such a scenario, empirical facts alone do not determine which validators we ought to use. Our choice of validators depends also on our assumptions and goals, which may differ from practitioner to practitioner and from context to context.

In contrast to the natural kind view is the skeptical view that the categories of psychiatric classifications are social kinds, almost entirely constructed by social processes (i.e., strong social constructionism). This view appeals to many critics of psychiatry, who point towards the obvious influence of sociocultural factors on the presentation of psychiatric conditions, and the inability of psychiatric research to identify diagnostically valid biomarkers. The social kind perspective is further supported by examples such as “hysteria” and “multiple personality disorder”, whose popularity among clinicians at various points in history has resembled the rise and fall of fashions. There is also increasing awareness that psychopathological phenomena are subject to “looping effects”, such that the very act of classification modifies the behavior of the individual classified, further supporting the social constructionist view⁹⁸.

However, this view in its strong articulation seems untenable, as it fails to take into account that scientific research has discovered relationships between neurobiological processes and psychiatric symptom clusters, albeit these relationships do not necessarily correspond to specific DSM or ICD categories. For instance, psychiatric research has identified hundreds of genetic variations that are associated with a range of psychiatric disorders, so that genetic influences on psychopathology often cut across DSM diagnostic boundaries. The relationship between genetic variants and psychopathology is therefore complex and transdiagnostic, but not absent or chaotic¹⁰¹.

The notion of practical kinds offers a different contrast to the essentialist perspective on natural kinds, and aligns with the soft naturalist view that psychiatric science is both a scientific and social process. There may be no “natural joints” in psychopathology, but there are scientific facts in the form of symptom patterns and co-variation that constrain any scientific attempts at nosology. Within these constraints, the boundaries that we draw will often reflect our pragmatic goals, and diagnostic thresholds will be influenced by both facts and values. Practical kinds are useful heuristic constructs that categorize the neurophysiological and psychological space in ways that serve our scientific and clinical goals. The pragmatic nature of psychiatric classification is also supported by considering the history of psychiatric nosology, which shows the contingent nature of our contemporary diagnostic constructs, and how our classifications would have looked quite different had certain key historical figures in psychiatry not existed or had they made different choices.

Distancing ourselves from essentialist assumptions about natural kinds in psychopathology allows us to appreciate the complexity of mental disorders, and makes it possible for us to map and model psychiatric phenomena using different approaches. For example, idiographic approaches focus on the uniqueness of the individual psychiatric patient – how his/her mental health problems arise from a specific combination of predisposing factors, developmental history, life experiences, behavioral adaptations, and psychological defense mechanisms. Such an approach utilizes broad principles of psychobiological functioning to formulate a narrative specific to a patient. The aim of classification, then, is to aid the development of a clinical formulation.

The failure to identify etiologically-based disease categories has also spurred psychometric efforts to model psychopathology. Psychometric analysis goes beyond manifest variables, which can be directly measured or observed, to mathematically model latent or hidden variables, which cannot be observed directly and only emerge through statistical analysis. This quantitative statistics research program is exemplified by the Hierarchical Taxonomy of Psychopathology (HiTOP) consortium. This attempts to combine signs and symptoms of psychopathology into homogeneous traits, to assemble such traits into empirically-derived syndromes, and then to group these syndromes into spectra (e.g., “internalizing” and “externalizing”)…

Another strand of philosophical inquiry has focused on the use of operational definitions employed by the DSM. In an effort to improve inter-rater reliability and to facilitate psychiatric research, the DSM from its third edition on has offered operationalized criteria for each disorder that specify details such as a list of (relatively specific) symptoms, number of symptoms that must be present, and the duration for which they must be present. How should the relationship between the criteria and the disorder be conceptualized? Lack of clarity in this regard leads to another form of confusion, in which operational criteria are thought to constitute the disorder itself.

Operational definitions are partial definitions that do not specify all the details of the phenomena being studied. They have an element of vagueness that becomes evident when new scientific questions force us to articulate concepts with greater precision. The DSM excluded non-specific symptoms (such as anxiety in depression) from operational criteria, but these symptoms as still part of the syndrome being described (e.g., depression). Moreover, the polythetic nature of DSM criteria allows for many different symptom configurations to meet disorder threshold, but these different symptom configurations are not seen to constitute different disorders. Instead, they are better understood as different ways in which we can identify a disorder.

K.S. Kendler has elaborated on the distinction between diagnostic criteria as indexical and constitutive. When diagnostic criteria are regarded as indexical, they are understood to be fallible ways to identify a disorder; when they are regarded as constitutive, the symptom criteria are the disorder. According to Kendler, the DSM criteria are intended to be indexical, and viewing them as constitutive is a conceptual error. Thus, for example, there are 227 ways to meet DSM criteria for major depression, but these are different ways of indexing major depression, not 227 types of major depression. There is no single and privileged correct operationalization; rather, different operational definitions can be refined and optimized for different purposes.

Taken together, an emerging contemporary view of psychiatric taxonomy incorporates the dimensionality of psychopathology (there are few discrete entities), insights from complex dynamic systems (relatively stable symptom patterns can emerge from irreducible interactions between multiple factors), and perspectives from embodied cognition (causal mechanisms traverse the brain, body and environment). Such a view of psychopathology does not render categorical diagnostic systems such as the DSM and the ICD invalid or useless, but it encourages us to give up an essentialist bias that has led us to reify them – to attribute them a correspondence to objective reality that they do not possess.”

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Questions in the naturalist-normativist debate

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Clinical applications of embodied/4E cognition

“Several conceptual frameworks grounded in the embodied/4E perspective have been applied to mental disorders as a whole. These frameworks view mental disorders as representing disruptions to sense-making, a view that is consistent with attempts to bridge the naturalist-normativist divide, with an emphasis on the adaptive fit between individual and context that aligns with soft naturalism. They also share a vision that embodied/4E cognition serves as an integrative framework for the conceptualization, study and treatment of these conditions, consistent with an emphasis on multi-disciplinary and pluralist approaches. Additionally, there have been several efforts to develop descriptive and explanatory models of particular mental disorders from an embodied/4E perspective.

A focus on embodied cognition leads to a view of mental disorders as constitutionally complex, involving biological, cognitive-emotional, environmental and sociocultural aspects. This perspective emphasizes both biology and agency, acknowledging biological scales of enquiry as relevant without reducing the explanatory importance of experience and choice. It also incorporates ideas of dynamical constitution and downward causality to break down the received mind-body divide, and aligns well with the notion of mental disorders as fuzzy mechanistic property clusters.

Through the notion of embedment, these frameworks emphasize the active and historical role of the physical and sociocultural environment. All organisms, particularly humans, are deeply historical and ecologically informed creatures. Shaped by our evolutionary, sociocultural and developmental pasts, we are understood to strive to adapt to the present context and predicted future. Applied to psychiatry, this allows integration with perspectives such as evolutionary psychiatry, cultural psychiatry, and developmental psychopathology.

In the embedded view, however, culture is not seen only as a historical force having influence across development, but also as a living context. In this “constitutional view”, culture is seen as a “shared world” or structure of knowledge, meaning and artifact, constituted by ongoing engagement. Such a shared world represents a historical context for the development of individuals and the way they make sense of the world, but also continues to play out in the moment-to-moment interaction of individuals, including in the clinical encounter. Embeddedness therefore pushes clinicians to actively consider the role of culture in the lives and histories of their patients, and in the clinician-patient interaction.

Via the notion of enactivism, these frameworks subscribe to a process orientation, with mental disorders not viewed as static problems/dysfunctions in the brain or psyche, but rather as constantly unfolding patterns of how we make sense of and engage with the world. Through interactions with their specific environment and its particular affordances, thinking beings create and discover meaning for themselves. Rather than stemming from some underlying “cognitive error” or “psychic disturbance”, mental disorders emerge within the circular relationships between patient and world – as a maladaptive pattern of sense-making.

This process orientation accords well with the focus of neuroscience and computational psychiatry on active inference, whereby predictive processing frameworks formally model how organisms develop probabilistic assessments of their environment so as to adapt optimally. Indeed, several authors have considered how best to integrate such frameworks with embodied/4E approaches, noting that the brain-mind, including interoceptive components, engages in embodied predictive processing in order to maintain enactive engagement with the environment. In their embodied/4E account, Friston and colleagues suggest the term enactive inference. Their framework bridges representational and non-representational approaches, providing a pluralistic, yet formal and mechanistic, account of a range of psychiatric conditions, often with a particular focus on interoception and bodily states.

In the clinical setting, given the central role of affordances and affectivity within the enactive view, a process orientation accords with psychotherapies that draw patients’ attention to early maladaptive schemas and current emotional dynamics in order to better learn to navigate them – an exercise in sense-making about sense-making. Further, from the enactive perspective, therapeutic interventions in psychiatry seek to improve the fit between the individual and his/her environment. This can in turn be achieved either by altering the sense-making and behavior of the individual, or by changing the world around him/her. This entails integration with notions of social psychiatry and environmentally focused mental health interventions.”

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I enjoyed all the commentaries, and I am grateful to all the commentators. I was particularly drawn to the article by Damiaan Denys, who articulated something important about how psychiatry is shaped by the forces of society:

“On closer inspection, we should even recognize that psychiatry, more than any other medical discipline, is being determined not by science but by society. All psychiatric symptoms are ultimately defined on the background of what is commonly agreed upon as normality. Normality is established not by science but by society. Normal is individual behavior that conforms to the most common behavior. Fluctuations in prevalence of mental disorder across culture and time are not caused by sophisticated adaptations of scientific criteria by experts, but pushed by societal waves. Autism and attention-deficit/hyperactivity disorder have become 100-fold more common due to changing perspectives on education and productivity. Long before misophonia became known in psychiatry and sporadically entered scientific articles, the disease term circulated globally on the Internet between interest groups. Often psychiatry is lagging behind social developments. Only in 1974 did homosexuality disappear as a disorder from the DSM-II, and only in 2019 did conditions related to sexual identity disappear as mental disorders from the ICD-11.

We should accept that psychiatry no longer shapes itself. The course and faith of psychiatry is not determined by psychiatrists or philosophers, but by socio-economic variations fueled by influencers on social media. The current and ongoing identity crisis in psychiatry is due to the yet-to-be-embedded realization that psychiatry as a scientific discipline has lost control of itself, sadly popularized by the universal theme of mental well-being…

Mental disorders are not spiking because more patients are developing psychiatric diseases, but because the ideal of individual autonomy has become the standard of normality across the globe. It is no coincidence that anxiety and depression are the most common mental disorders. They express our failure in attempting to fulfil the impossible demand of individual autonomy. We are more anxious not because our world has become more dangerous – on the contrary it has become safer – but because our desire for control is out of proportion. We are more depressed not because our lives are hopeless and meaningless – the opposite is actually true – but because we are confronted with too many choices, we are set up for unrealistically high expectations, and blame ourselves for any and all failures.”

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1. Karl Friston and I… co-authors on a paper together? Who would’ve thought?!