International Journal of Law and Psychiatry
Depression and suicide are natural kinds: Implications for physician-assisted suicide
Introduction
What kind of thing is classified by the term ‘suicide’? Is it a medical condition? Or is suicide better understood as a social (or socially constructed) phenomenon? This article addresses these questions by focusing on the question of whether depression and suicide are natural kinds. I subsequently examine what bearing these issues regarding the naturalness of suicide have on the thorny issue of assisted suicide.
A high proportion of patients who request physician-assisted suicide are suffering from depression or present depressive symptoms (Levene & Parker, 2011). This circumstance raises important questions about how depression affects individuals' judgments about ending their lives, and in particular, whether depression hampers individuals' capacity to make competent decisions about assisted suicide. Moreover, the high prevalence of depression among individuals seeking physician-assisted suicide highlights the importance of issues regarding the specific ways in which depression can alter patients' decision-making process and the extent to which the kinds of depression that are a precursor to suicide are treatable.
The article proceeds as follows. In 2 Natural kinds in psychiatry, 3 Are depression and suicide natural kinds?, I examine questions concerning the naturalness of depression and suicide. In Section 2, I critically examine the views of Thomas Szasz and Ian Hacking who offer different reasons for rejecting the existence of natural kinds in psychiatry. I subsequently propose a positive theoretical account of natural kinds in psychiatry that maintains that some mental disorders are natural kinds insofar as members of a kind share the same biological causal structure. More specifically, natural kinds in psychiatry (e.g., schizophrenia, bipolar disorder) are stable objects of classification whose characteristic signs are determined by networks of stable biological mechanisms. Analyses of Szasz and Hacking fail to establish that these natural kinds (i.e., mechanistic property cluster kinds) do not exist. In Section 3, I argue that depression and suicide are natural kinds because they are classes of abnormal behavior associated with serotonin dysfunction in various brain structures (i.e., the amygdala, anterior cingulate, prefrontal cortex, and hippocampus). In Section 4, I consider the implications of this analysis for assisted suicide. My focus is on questions concerning the extent that depression hampers individuals' capacity to make sound decisions and the potential to treat more severe forms of depression.
Section snippets
Natural kinds in psychiatry
In philosophy of science, the distinction between natural kinds and artificial kinds refers to a distinction between kinds (or classes) of things that are discovered and invented respectively (see Bird & Tobin, 2010). Natural kinds are classes of naturally occurring objects, properties, or processes that exist independent of and are discovered by classifiers (e.g., electrons, gold, H20, fish). By contrast, artificial kinds are classes of objects that are imposed on nature and invented by
Are depression and suicide natural kinds?
In the following section, I argue that depression and suicide are natural kinds insofar as they are classes of (abnormal) behavior that are underwritten by stable neurobiological mechanisms. In articulating this argument, I presuppose a diathesis-stress model wherein individuals may inherit a neurobiological vulnerability to depression and suicide (Mann, Waternaux, Haas, & Malone, 1999). In this model, individuals who inherit a susceptibility (diathesis) to depression and suicide are more
Implications for physician-assisted suicide
Issues regarding the naturalness of depression and suicide are highly relevant for assisted suicide. In the context of physician-assisted suicide, the fact that depression is a natural kind is significant because it is precisely the natural (i.e., biological) basis of depression that allows physicians to make projectable inferences about patients who are considering assisted suicide. As discussed in the second section of this article, natural kind terms (e.g., ‘depression,’ ‘schizophrenia’) are
Conclusion
In this article, I argued that depression and suicide are natural kinds insofar as they are classes constituted by distinct neurobiological mechanisms, e.g., deficient serotonin activity due to insensitive 5-HT receptors. The significance of this argument is that the natural (biological) basis of these classes allows for projectable inferences to be made about members of a kind. In the context of assisted suicide, inferences concerning the decision-making competence of depressed patients
Acknowledgments
I am grateful to Kate Padgett-Walsh, Paul Thagard, Stephen Biggs, Inmaculada de Melo-Martín, and an anonymous referee of this journal for very helpful comments and suggestions on earlier drafts of this article. I would also like to express my gratitude to Ian Hacking, Christopher DiTeresi, and Bill Wimsatt for earlier discussions that helped to shape my views on natural kinds in psychiatry.
References (156)
- et al.
Mortality of patients with mood disorders: Follow-up over 34–48 years
Journal of Affective Disorders
(2002) - et al.
Cognitive function in major depression
Journal of Affective Disorders
(1992) - et al.
Lifetime rates of suicide attempts among subjects with bipolar and unipolar disorders relative to subjects with other axis I disorders
Biological Psychiatry
(1996) In defense of classification
Studies in History and Philosophy of Biological and Biomedical Sciences
(2001)- et al.
A meta-analysis of psychotherapy and medication in unipolar depression and dysthymia
Journal of Affective Disorders
(2008) - et al.
Origins of the desire for euthanasia and assisted suicide in people with HIV-1 or AIDS: A qualitative study
Lancet
(2001) - et al.
Deaths: Final data for 2001
National Vital Statistics Reports
(2003) - et al.
5-HIAA in the cerebrospinal fluid: A biochemical suicide predictor?
Archives of General Psychiatry
(1976) Diagnostic and statistical manual of mental disorders
(2000)- et al.
Physician-assisted suicide and euthanasia in Washington state: Patient requests and physician responses
Journal of the American Medical Association
(1996)
Discovering complexity: Decomposition and localization as strategies in scientific research
Hopelessness and suicidal behavior: An overview
Journal of the American Medical Association
Are psychiatric kinds ‘real’?
European Journal of Analytic Philosophy
Mood-lowering effect of tryptophan depletion: Enhanced susceptibility in young men at genetic risk for major affective disorders
Archives of General Psychiatry
Natural kinds
On the distinction between disease and illness
Philosophy and Public Affairs
What a theory of mental health should be
Journal for the Theory of Social Behaviour
Health as a theoretical concept
Philosophy of Science
A rebuttal on health
Observations, explanatory power, and simplicity: Toward a non-Humean account
How to be a moral realist
What realism implies and what it does not
Dialectica
Realism, approximate truth, and philosophical method
Realism, anti-foundationalism and the enthusiasm for natural kinds
Philosophical Studies
Homeostasis, species, and higher taxa
Realism, natural kinds, and philosophical methods
Interest in physician-assisted suicide among ambulatory HIV-infected patients
The American Journal of Psychiatry
Depression, hopelessness, and desire for hastened death in terminally ill patients with cancer
Journal of the American Medical Association
Suicidal behavior runs in families: A controlled family study of adolescent suicide victims
Archives of General Psychiatry
Risk factors for suicide in psychiatric outpatients: A 20-year prospective study
Journal of Consulting and Clinical Psychology
Further evaluation of urinary 1-hydroxycorticosteroids in suicidal patients
Archives of General Psychiatry
Foundations of physiological psychology
Desire for death in the terminally ill
The American Journal of Psychiatry
Suicide: The philosophical dimensions
Suicide
Classifying madness: A philosophical examination of the Diagnostic and Statistical Manual of Mental Disorders
Psychiatry and philosophy of science
Discovering mechanisms in neurobiology: The case of spatial memory
Are psychological and pharmacologic interventions equally effective in the treatment of adult depressive disorders? A meta-analysis of comparative studies
The Journal of Clinical Psychiatry
The return of Phineas Gage: Clues about the brain from the skull of a famous patient
Science
Health-care needs and distributive justice
Philosophy and Public Affairs
Just health care
Just health: Meeting health needs fairly
Depression: Perspectives from affective neuroscience
Annual Review of Psychology
Executive deficits in major depression
Acta Psychiatrica Scandinavica
Depression: The case for a monoamine deficiency
The Journal of Clinical Psychiatry
Serotonin function and the mechanism of antidepressant action: Reversal of antidepressant induced remission by rapid depletion of plasma tryptophan
Archives of General Psychiatry
Depression in primary care: Volume 2. Treatment of major depression
Predicating repetition of suicide attempt: A prospective study of 50 suicide attempters
Archives of Suicide Research
Natural kinds and biological taxa
Philosophical Review
Cited by (16)
Classification, kinds, taxonomic stability and conceptual change
2021, Aggression and Violent BehaviorCitation Excerpt :As Khalidi contends, “if classification is always relative to certain interests, we would expect some [categories] to reorganize some of the same entities in different ways without displacing existing ones” (Khalidi, 1998, p. 42). Philosophical understandings of the concept of natural kinds and debates about the usefulness of the very concept for understanding scientific classification and conceptual change are still evolving as philosophers of science expand the focus of their inquiry to a number of diverse and interdisciplinary areas of science (see e.g., Bolker, 2013; Brigandt, 2003, 2010, 2012; Bursten, 2016; Godman, 2013; Kendig, 2016a, 2016b; Ludwig, 2017; Ludwig, 2018; Muszynski & Malaterre, 2020; Ruphy, 2010; Slater, 2015; Slater, 2013; Tabb, 2019; Tsou, 2013; Zachar, 2000). Natural kinds realists have expressed optimism that just so long as the aims of classification in a given scientific domain are broadly epistemic, natural kinds in some form (e.g., HPC, MPC) will be in the offing (e.g., Boyd, 2019; Kendler et al., 2011; Khalidi, 2013), and there may be different epistemically admirable ways of conceptually carving up the world that cross-cut each other (e.g., Khalidi, 2013).
Exposure to terrorism-related information on SNSs and life dissatisfaction: The mediating role of depression and moderation effect of social support
2021, Technology in SocietyCitation Excerpt :Depression refers to “a depressive disorder that affects how a person thinks, feels or acts, that disrupts social or occupational functioning” [45]; p. 775). Depression affects and changes the feeling and function of human activities in their daily life [46]. It interferes negatively an individual's daily life activities, such as studying, eating, sleeping, and enjoying [47].
Should social pragmatic communication disorder be included in DSM-5? On uncertainties, pragmatic considerations, and the psychiatric kind debate
2023, European Journal for Philosophy of ScienceThe Many Faces of Realism about Natural Kinds
2023, Journal for General Philosophy of ScienceReactive natural kinds and varieties of dependence
2022, European Journal for Philosophy of ScienceDepression and Physician-Aid-in-Dying
2022, Journal of Medicine and Philosophy (United Kingdom)