Tidying up psychiatry
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This is a cross post with psychiatricethics.com
Psychiatry’s progress lags behind that of other areas of medicine: the last half-century has seen impressive gains in life expectancy and reductions in mortality for most infectious and cardiovascular diseases and some cancers, yet suicide rates—which are associated with depression—have steadily increased, and longevity for those with serious mental illness falls more than two decades short of the general population. (Colton and Manderscheid 2006; Insel 2013; WHO 2002, 2012). What can we do about this?
The Oxford Loebel Lectures and Research Programme (OLLRP) aim to address this problem by going back to theoretical basics. Despite relatively recent advances in psychiatry and related fields—such as the ‘psychopharmacology revolution’ of the 1950s, the ‘decade of the brain’ in the 1990s, and contemporary neuroscientific research initiatives like the Human Brain Project—psychiatrists remain, in an important sense, confused about mental illness. Medically-minded psychiatrists prioritise biological factors in understanding it, psychotherapists prioritise psychological factors, while eclectics—adherents of the so-called biopsychosocial model—favour an all-encompassing approach that recognises the relevance of biological, psychological, and social factors and tries to incorporate all of them.
Psychiatry, then, is theoretically fragmented. Evidence increasingly shows that biological, psychological, and social perspectives are all important. For example, progress has been made in understanding how the brain changes at the cellular molecular level when we learn and retain information (Kandel 2001); the relationship between genetic factors, life events, and psychiatric disorders (Nemeroff and Vale 2005); the neural basis of mental illnesses (Andreasen 1997); the effects of psychotherapy on the brain (Gabbard 2000); the neuroscience of free will (Haggard 2008); and the role of oxytocin in post-birth maternal depression and its subsequent negative effects on children’s mental health (Apter-Levy et al. 2013). Despite this, however, there is no widespread consensus in psychiatry about how best to combine biological, psychological, and social considerations into a coherent account of mental illness. Some have argued that, without a rationale for integrating them, merely acknowledging the relevance of biological, psychological, and social factors does little to advance progress in psychiatry: it is comparable to a list of ingredients, when what is really required is a recipe (McHugh and Slavney 1998; McLaren 1998; Ghaemi 2009, 2010). Philosophical analysis is required to identify the conceptual shortcomings of the biopsychosocial model and help psychiatrists meet these shortcomings.
So, what is the biopsychosocial model? The term ‘biopsychosocial’ was coined by Roy Grinker in a 1954 lecture (published only forty years later: Grinker 1994) but popularised by George Engel. Engel (1977) drew upon general systems theory—according to which the various ‘levels’ of conceptualising illness (biological, psychological, social) form a hierarchy with some laws and principles applying only within a level and others applying to the system as a whole—to envisage a holistic way of understanding and scientifically studying the mind.
By itself, however, Engel’s account does not tell us what a biopsychosocial psychiatry should look like. Is the claim that mental illness involves biological, psychological, and social factors an empirical, falsifiable hypothesis? A pre-theoretical commitment, as it seems to be for Engel? A reminder to consider the patient as a whole, rather than merely his or her disease (an approach reminiscent of William Osler’s medical humanism)? A reminder to be open-minded to the possibility that the aetiology of mental disorders may not be purely biological or purely psychosocial—a message that emerges from Kenneth Kendler’s work at the intersection of philosophy and psychiatry? And, in what sense is the biopsychosocial model a model: is it supposed to represent psychiatric illness the way that the double helix model represents DNA, and if so how? Or, is it more comparable to a Kuhnian paradigm: a set of theories, values, and assumptions shared by the practitioners of a science? Engel took the latter view, with his definition of a scientific model reflecting Thomas Kuhn’s conception of a paradigm.
If the biopsychosocial model is to be understood in Kuhnian terms, we might question whether it is desirable that psychiatry should adopt it. If adopting it would involve endorsing the empirical claim that mental disorder always involves biological, psychological, and social factors, then it is hardly desirable that all psychiatrists subscribe to it, since there is insufficient reason to believe it is true: we do not have evidence that all or even most mental disorders involve such an etiology. Perhaps the biopsychosocial model need not involve such a strong claim—but, in that case, it is difficult to see how it might constitute a Kuhnian paradigm of the sort envisaged by Engel. If, for example, endorsing the biopsychosocial model involves only making an Oslerian commitment to treat the patient as a whole, or being open-minded to the possibility that the causes of mental disorders are spread across biological, psychological, and social categories, then it is less a Kuhnian paradigm and more an expression of good manners, humanity, and common sense.
In any case, we might question the value of a unifying paradigm for psychiatry. We currently lack an understanding of the extent to which progress in psychiatry happens because of its theoretical fragmentation, and the extent to which progress happens in spite of this. Is there a sense in which psychiatry’s lack of a unifying paradigm is a strength, and a sense in which it is a weakness? Is it inevitable, or even necessary, that psychiatry should be theoretically heterogeneous? The suggestion that that a biopsychosocial approach to psychiatry requires a recipe presupposes an answer to these questions: it assumes that in order to be successful, a biopsychosocial model must make psychiatry more like a mature, Kuhnian science that is united by a single paradigm. Yet this assumption may turn out to be premature.
Another concern is raised by the division of contributors to mental illness into biological, psychological, and social categories. Are these the right categories to consider? And, what sort of categories are they, exactly? Philosophers of mind, for example, disagree about how psychological states should be conceived. Nobody who has written about the biopsychosocial model says much about what the social category should involve. And, why not ‘drill down’ further than biology in the hierarchy of levels—by including chemical and physical levels too?
Finally, the general systems theoretical conception of a hierarchy of levels is not without its problems. Whilst Engel introduced it as a way to encourage psychiatrists (and, indeed, those working in other areas of medicine too) to give due recognition to the role played in illness by the psychosocial, this hierarchical view itself encourages prioritisation of the biological by representing the biological as more basic than the psychological or the social. Yet it is far from clear that, for example, describing memory in biological terms is more basic than a psychological description. Indeed, what would such a claim even mean? To answer this, we need to understand how these categories relate to each other: do they reduce to each other, for example? And, if so, in what ways?
These are just some of the questions being addressed by the OLLRP in an effort to tidy up psychiatry. In October, Oxford will host the inaugural Loebel Lectures, to be delivered by Kenneth Kendler (details here). In his lectures, Kendler will consider both the empirical evidence for biopsychosocial interactions in mental illness, and the conceptual and explanatory relationships between them.
Colton, C.W. and Manderscheid, R.W. 2006: ‘Congruencies in increased mortality rates, years of potential life lost, and causes of death among public mental health clients in eight states’, Preventing Chronic Disease 3/2.
Engel, G. 1977: ‘The need for a new medical model: a challenge for biomedicine’, Science 196/4286: 129–36.
Ghaemi, S.N. 2009: ‘The rise and fall of the biopsychosocial model’, British Journal of Psychiatry 195:3–4.
—— 2010: The Rise and Fall of the Biopsychosocial Model: Reconciling Art and Science in Psychiatry (Baltimore, MD: Johns Hopkins University Press).
Insel, T. 2013: ‘The beginning of history illusion’, NIMH Director’s Blog, 9th January.
Kuhn, T. 1962: The Structure of Scientific Revolutions (Chicago: University of Chicago Press).
Leff, J., Kuipers, L., Berkowitz, R., Eberlein-Vries, R. and Sturgeon, D. 1982: ‘A controlled trial of social intervention in the families of schizophrenic patients’, British Journal of Psychiatry 141: 121–34.
Leff, J., Kuipers, L., Berkowitz, R. and Sturgeon, D. 1985: ‘A controlled trial of social intervention in the families of schizophrenic patients: two year follow-up’, British Journal of Psychiatry 146: 594–600.
McHugh, P.R. and Slavney, P.R. 1998: The Perspectives of Psychiatry (Baltimore, MD: Johns Hopkins University Press).
World Health Organization 2002: ‘Evolution 1950–2000 of global suicide rates (per 100,000)’.