Thursday, 14 January 2016

Loebel Lectures 2015: Steven Hyman

In this post Reinier Schuur (University of Birmingham) reports from the Loebel Lectures in Psychiatry and Philosophy held on the 3rd, 4th, and 5th of November 2015. The lectures were delivered by Professor Steven E. Hyman, former director of the NIMH (National Institute of Mental Health), and currently at the Stanley Center for Psychiatric research, at the Broad Institute of MIT and Harvard. 

Steven Hyman gave his lectures on ‘The theoretical challenge of modern psychiatry: no easy cure’, which dealt with the future of psychiatry and the potential ‘collision’ between patient’s lived experience and our neurobiological understanding of mental disorders. A small conference was also held on the 5th of November on Hyman’s lectures, where several philosophers of psychiatry spoke, such as Derek Bolton, Tim Thornton, Jonathan Glover, and Julian Savulescu.

The title of the first lecture by Hyman was ‘The problem of modern psychiatry: the collision of neurobiological materialism with the experience of being human’. Hyman argues that there are two perspectives of the patient in psychiatry. The first is of the patient as subject, which concerns the patient’s lived experience of mental illness from a first-person perspective and self-narratives. The second is of the patient as object, as a ‘thing’ where something goes ‘physically wrong’, either in terms of their brain, or their brain in relation to the environment in some ‘mechanistic’ way.

Hyman is skeptical that a smooth ‘conceptual integration’ between these two perspectives will be possible, but leaves his arguments for this for the next two lectures. For the first lecture, Hyman sets out the history and future for the ‘mechanistic picture’ of mental illness.

The history of 20th century psychiatry is a mixture of break-throughs and let-downs. Accidental findings of efficacious drugs were a clinical blessing but an intellectual curse, because they made us focus on particular targets for treatment based on prior success rather than looking at new fundamental ways of treating mental disorders. Because of this, the concept of predictive validity led psychiatry into a ‘cul de sac’, rediscovering the same mechanisms. And while the DSM-III greatly improved construct validity and diagnostic reliability, it eventually led to a ‘reification’ of diagnostic categories, an overly reductionistic approach, and an impoverishment in models of psychopathology.

Moreover, the DSM as a framework hinders findings from basic research sciences from properly informing psychiatry, because DSM categories do not converge on valid disease entities, evident in their high levels of co-morbidity. And categorical approaches might have been motivated to counter the anti-psychiatry movement to show that psychiatrists were dealing with were ‘real’ diseases, thereby biasing against promising dimensional approaches which might have had better research and clinical utility. So what’s the up-shot of the ‘mechanistic picture’?

While Hyman gives us a sobering account of the progress of psychiatry, there is still room for ‘cautious’ optimism. One of the things we have learned over the last decades is of the high correlations of aggregate genetic factors for the prevalence of mental disorders. The real challenge here is that in order to have a proper genetic understanding of mental disorders, we need better observations of their effects, which requires both new technologies and large scale ‘big-data’ genetic analysis. Statistical power matters, as Hyman says.

And the good news is that we have begun to ditch the old ‘Mendelian’ way of thinking about genetic analysis which hindered previous research programmes, innovating new statistical approaches and factoring in environmental factors in genetic analysis in the form of epigenetics, and the overall cost of technological analysis has greatly decreased. Moreover, dimensional approaches are increasingly being accepted over categorical ones for research purposes. While it may take decades to reap the fruits of these new innovations and changes, there is some hope for optimism. The next question is, given this potential trajectory of the future of psychiatry, how will future findings relate to the patient’s lived experience of their mental illnesses? This is the question addressed in the second lecture.

The title of the second lecture was ‘Science is quietly, inexorably eroding many core assumptions underlying psychiatry,’ which dealt with the ‘complex marriage of neurobiological materialism with the ‘psychosocial world’. In this talk, Hyman tried to show that psychiatry still maintains a ‘sloppy Cartesianism’ in how it artificially distinguishes between social, psychological, and biological factors and levels of explanation. One way to see this is how these distinctions become untenable when considering the ways that ‘lived experience’ is part of our biology and gets, so to say, ‘under the skin.’ The best example of things is our experience of learning and its relation to learning mechanisms, which are relatively well understood in terms of neural connectivity strengthening and synaptic weighting. Now while our understanding of the mechanisms underlying brain changes induced by psychotherapy are still not well understood, there is no reason to think that future research will reveal the relevant mechanisms here as well.

In either case, once such findings become available, it is clear already that the crude distinction between the biological, psychological, and social, cannot be maintained, since they are all part of each other. But if this is the case, asks Hyman, than where is the ‘collision’ between lived experience and biology that he is so worried about. The collision comes about, says Hyman, because our experience and intuitions about ourselves as human agents are not ‘veridical’ to the story that neurobiology gives us for the explanations for our decision-making and self-perceptions. some neuroscientists think that our self-narratives are a total illusion as explanations for why we do the things that we do, the real explanation being mechanistic, though Hyman did not go so far as to endorse this view. This brings us to the conference, which took place before the final lecture.

Too much material, though very rich and relevant, was covered in the mini-conference to do justice to it all here. I will briefly summarise Tim Thornton’s talk in particular, because of its relevance. Thornton, and other philosophers during the Q&A sessions after the lectures, questioned the epistemic status of Hyman’s use of the concept of ‘collision’ between our lived experience and neurobiology. While most agree that we confabulate the reasons for our actions quick often, this concept suggests that our lived experience goes contrary to neurobiology in quick a strong way. Hyman agreed, and settled on the concept of a ‘gap’ between these two levels of explanation.

This brings us to Hyman’s final lecture, ‘Can we see through the Cartesian fog? Addiction, Volition, Insight,’ which dealt with elaborating on the gap between lived experience and neurobiology. He illustrated this by focusing on the mechanisms of reward circuitry and dopamine release in our understanding of addiction. While many addicts might recover on their own, severe cases of addiction have high genetic correlates involved in their onset. Hyman’s worry is that in those cases, addicts will develop self-narratives of why they started and continue using that might be at odds with, or even go contrary to, the strong underlying mechanisms that actually accounts for their drug use. These addicts might have dysregulated dopamine release systems, something they do not have insight into. Hyman is also concerned about the consequences for criminal responsibility for mentally ill people in the legal system, and that there might be a gap between the story we tell ourselves about responsibility and what the science shows.

Even if one disagrees with Hyman’s formulation of the problem between the relation between our lived experience and what neurobiology might end up telling us about mental illness, he is certainly right to draw attention to the issue of integrating these two levels of experience. Whether our brains really are ‘spin-doctors’ that confabulate the reasons for our actions in such a way that cannot be unlearned remains a hotly debate issue. The great benefit of this lecture series is that Hyman has drawn our attention to this problem and set a framework for future discussions at this crucial intersection between philosophy and psychiatry.

No comments:

Post a Comment

Comments are moderated.