Tuesday, March 14, 2023

Mediated by the brain not necessarily the same as caused by the brain

Further to my last post, it may be worth thinking a bit more about why psychiatry, and neuroscience in general, have taken us down the route of the mereological fallacy. It’s become very common to view ourselves in terms of our brains (see eg. previous post). This, of course, has particular implications for psychiatry.

The reason this happens is because people no longer want to make a distinction between the psychological and the biological. It is said to be a false separation (see eg. another previous post). The fear is that the mind/body split of Cartesianism is being perpetuated by seeing mental disorder as psychological, said to be implying it is not biological (see eg. yet another previous post). Better to do away with any distinction at all, is the thought.

As I've said before (see eg. previous post), RenĂ© Descartes (1596–1650) was the first to apply a natural-scientific mechanistic approach to life  Animate and inanimate matter were understood by the same mechanistic principles. Animals were, therefore, regarded as machines; and human physiology was also seen as mechanistic. Descartes stopped short, though, of including the human mind in this mechanistic framework. The soul was denied any influence in physiology. Descartes thereby avoided the materialistic implication that man himself is a machine. The split he created between mind and brain is what is referred to as Cartesianism. 

One of the first to challenge this perspective was Georg Ernst Stahl (1660–1734). He claimed that living things possess an immaterial soul, although he did not necessarily mean a transcendent soul, that provided the key element of movement to matter within the living body. His ‘dualistic’ notion was different from that of Descartes, in that he differentiated organic life from the inorganic, not the soul from the body. Unlike Descartes, he proposed that the soul and body are not separate but integrated in the organism. Despite his vitalism, Stahl originated a holistic perspective in the life and human sciences. This perspective formed the basis for his emphasis on psychosomatic medicine, and a focus on clinical medicine rather than the physical sciences. But his vitalism is as much derided, now, as Cartesianism. Although it makes sense to distinguish life from inanimate matter, a more modern way of expressing this is through enactivism, rather than vitalism (see eg. previous post). 

The mereological fallacy helpfully highlights that even though mental disorder is mediated by the brain, this does not imply that it is necessarily represented in the brain. Of course, cerebral disease or abnormality can cause mental disorder. But the vast majority of mental disorder is functional, not structural. It is not represented in the brain as such. It doesn’t make sense to see it as being in the brain. Even delirium and dementia caused by cerebral disease should not be seen as being in the brain as such. It’s people that become delirious or demented, not their brains. But the cause of organic mental disorder, such as delirium and dementia, is abnormality in the brain, whereas for functional disorder, it is not. It is more to do with the whole person, not just the brain, and cannot be understood mechanically. The mental is as much biological as the physical. Because the assumption is that mediation by the brain means that all mental disorders must be in the brain, people fail to recognise that mental disorders are not always in the brain. Being more careful and avoiding language to say that the brain is the person would be a start towards that realisation.

Monday, March 13, 2023

People are not their brains

I have been thinking about the implications of the mereological fallacy (see previous post) for psychiatry. Psychiatry must stop identifying the brain with the person (see eg. another previous post). 

People need to be understood as wholes, as their brains are only part of them. The brain mediates cognition, emotions and behaviour but it is not the brain that perceives, thinks, feels and acts. It is people as a whole that do that (see eg. yet another previous post).

Brain disease or abnormality can cause mental disorder. Such organic mental disorders can be due to a primary brain disorder or secondary to a systemic illness, or result from an exogenous toxic agent, or be due to physical withdrawal of an addictive substance. But not all mental disorder is due to brain disease or abnormality. Mental disorder shows through the brain but not necessarily in it.

Brain disease can be detected when assessing for mental disorder by disturbances of sensorium and cognitive functioning (see eg. previous post). In particular, level of consciousness, orientation, attention and memory are affected. Jaspers in his General Psychopathology referred to the "state of consciousness" as the "momentary whole" of the "psychic state". Brain disease may be detected by its effects on consciousness and that sense of wholeness.

Depression and schizophrenia, as examples of functional mental disorders, need to be understood in meaningful context. But the meaning of dementia, as an example of an organic mental disorder, could be said to be more to do with brain abnormality. It's people that become demented rather than their brains, as such, but the brain abnormality of dementia, whether Alzheimer’s or whatever, affects the wholeness of people's experience of themselves.

Wednesday, March 08, 2023

Publication bias in antidepressant trials

Erick Turner was a former US Food and Drug Administration (FDA) reviewer. At the FDA he was aware of publication bias due to negative results of trials tending not to be published. As he says in an interview with Ayurdhi Dhar from Mad in America (see edited transcript and podcast), there was a “disconnect between what clinicians were seeing and what the FDA reviewers were seeing, and what was known to the FDA and the pharmaceutical industry”. 

I’ve always argued that the apparent small difference between antidepressant and placebo in clinical trials could be due to placebo amplification because of unblinding (see eg. previous post). Although maybe unlikely, I suppose it’s possible that publication bias could completely explain this artefact. Certainly the pharmaceutical industry has taken advantage of the clinical reluctance to consider this issue, although publication bias also plagues psychotherapy trials. As Erick says, the decision as to whether a clinical trial is “good science shouldn’t depend upon whether the results were statistically significant”.

Thursday, March 02, 2023

Reducing overprescribing in the NHS

The Department of Health and Social Care (DHSC) produced a report in September 2021 to reduce overprescribing of medication. According to the Sunday Express (see article), NHS England is due to unveil a scheme in the spring aimed at weaning the health service off a culture of ‘a pill for every ill’. 

As the DHSC report says, what’s needed to reduce overprescribing is already known: shared decision-making with patients; better guidance and support for clinicians; more alternatives to medicines, such as physical and social activities and talking therapies; and more Structured Medication Reviews (SMR) for long-term health conditions. The problem is that “Many patients do not feel that they experience a compassionate, coordinated service that pays enough attention to their individual needs, assets, values, preferences and priorities”. The College of Medicine (see webpage) launched its Beyond Pills Campaign in 2022. A cultural change to reduce the reliance on medication and to support shared decision-making would be very welcome, not least for mental health services.