Are psychiatric conditions really biological? A psychologist and a neurogeneticist offer conflicting views

Are psychiatric conditions really biological? Or should they be understood as fundamentally psychological problems with social causes?

It’s a vexed topic which got very different responses from two of my guests on NOUS. The clinical psychologist Lucy Johnstone is well-known as a savage critic of mainstream psychiatry. In our interview, she argued that so-called ‘diagnoses’ like depression, schizophrenia and bipolar disorder are totally invalid categories which should not be seen as biological in any meaningful sense. For her, psychiatry is in the dubious business of labelling common psychological responses to trauma as stable, biomedical problems.

At the other end of the spectrum, I had an excellent discussion with the Irish neurogeneticist Kevin Mitchell. He pressed the evidence that psychiatric conditions are highly heritable, and that genetic and developmental processes make a crucial contribution to the emergence of psychopathology.

I came away from both interviews impressed. Both thinkers, it seemed to me, presented a convincing and well-evidenced narrative. But it troubled me that I could find such apparently divergent perspectives convincing. Was I just being irrational or somehow feeble-minded!?   

It is tempting to see these viewpoints as wholly irreconcilable. But, despite first appearances, I think there is some interesting overlap.

For one, they both agree that many psychiatric diagnoses are not meaningful categories. Kevin thinks of conditions like schizophrenia, for example, as a rag-bag of symptoms artificially lumped together. He rejects the claim that the label describes a ‘natural kind’: a discrete category of things that share, clear, objective features.

Lucy agrees. In her language, the category of schizophrenia is ‘invalid’ and meaningless. She chuckled sympathetically when I quoted Richard Bentall's deliciously provocative claim 'Most psychiatric diagnoses are about as scientifically meaningful as star signs.' (from this book).

To make progress in treating mental distress, then, both think that false categories like schizophrenia need to be broken up into more helpful kinds of things....

For Lucy and the Power Threat Meaning framework which she advocates, this means identifying recurring patterns of feeling and behaviour that tend to emerge as meaningful responses to certain kinds of trauma and adversity. (Check out Part 4 in the PTM Framework Overview).

For Kevin, identifying how specific symptoms (like hearing voices) result from distinct biological pathways could provide the way forward to new insights and, eventually, new treatments. In an article on his excellent blog Wiring the Brain, for example, he advocates a kind of biology-up approach: we should 'identify strong biological effects and follow the trajectory of events...from altered development or function of some particular cell types and circuits in the developing brain to the ultimate emergence of particular pathophysiological states.' 

Although Lucy is resolute that many psychiatric ‘diagnoses’ are really psychological responses to adversity, she happily acknowledges the role of biology as a causal factor in more obviously neurological conditions like Alzheimer’s and autism. Moreover, she agrees entirely that the brain mediates all mental activity. And although Kevin is focussed on identifying biological pathways to pathology, he does accept the importance of experience in determining the emergence of psychological traits.

So does that resolve the tension between them? If I’m honest, not really. The overlap is interesting, but it disguises a more profound difference in outlook.

In the end, Lucy places the agency and experience of an individual at the core of her approach. As a neurogeneticist, Kevin is working to explain the emergence of traits via mechanisms which have no agency. Genes and cells don’t have intentions or experiences!

I guess this conflict reflects a deeper tension running through many of the topics I am tackling in NOUS. How we can understand ourselves as evolved, biological animals at the same time as free individuals, with minds and meaning?

It’s a knotty, knotty problem and one I can't let go just yet.

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Check out Kevin's book Innate: How The Wiring of Our Brains Makes Us Who We Are and also his blog Wiring the Brain.

Lucy's books include A Straight Talking Introduction to Psychiatric Diagnosis and Users and Abusers of Psychiatry. Her recent and ongoing project the Power Threat Meaning Framework can be explored here.

Follow NOUS on Twitter @NSthepodcast