Why isn’t Mental Illness a Brain Disease?

Illness is illness – impairment of normal function of part or all of the body. Why, then, do we have illness and mental illness as if they are different things? We all fall ill from time to time, it may be an infection, heart disease, liver, bones, joints, any organ including the brain. But when it comes to the brain we call it mental illness and it carries stigma.

Why should mental illness, or mental health, as the NHS calls it, be different? Why is it regarded as separate from ‘physical’ illness or health? Is the brain not physical like the heart? It may be ‘all in the mind’ but the mind is all in the brain. Many people thing that the mind is separate from the brain, it isn’t.

Mind and Body

The reason for this mind-body duality goes back to the renaissance and René Descartes (1596-1650), an important French philosopher and mathematician [remember cartesian co-ordinates on graphs; he invented them.] He wrote about the relationship between the mind and the body and got it dramatically wrong. The insubstantial mind, he thought, interacts with the substantial body in the pineal gland.  His idea of mind-body interaction was progress in its time. Previously the mind had been regarded as insubstantial and not subject to the laws of nature. By linking it to the body, he implied that the mind had a physical reality and that the laws of physics applied to it. We have stuck with this duality idea for too long.

We knew nothing much about the pineal gland until recent times except that it had little to do with the mind. It is part of the sleep-wake regulation mechanisms.

What happens in the brain? Chemical and electrical reactions, transmitter release, branching connections between brain cells and this results in something we call mind. Rather like the stomach produces digestion and the heart produces blood pressure, the brain produces mind.

Why do we persist with Descartes’s idea of the mind as separate from the brain? The two are linked, you cannot have one without the other. We are all familiar with the tragic loss of mind of people with Alzheimer’s disease whose brains shrivel away. There are hundreds of diseases where the function of the brain is temporarily or permanently disturbed and the mind is altered in parallel.

Duality

One reason for maintaining the mind as separate is the requirements of religious belief. After death, there must be a separate mind, or soul, that goes off somewhere nice to play a harp. This archaic idea is still being embedded in children’s minds from an early age. We can all see that the body decomposes after death and that there is no mind left behind.

Another reason has been that, until recently, we have not been able to see the brain and how it works. Now, thanks to scans, we can see that the brain works in different ways. In a coma for instance, the brain is working in a very different way from someone awake.

Modern Studies

There are ‘mental’ diseases where we cannot see a change in brain function, schizophrenia, bipolar disease, etc. There appears to be nothing wrong with the brain, it is just the mind. Just because we cannot see a change in the brain doesn’t mean that there isn’t one. “Absence of evidence is not evidence of absence.”

Increasingly sophisticated scans and other techniques are now allowing us to see more and more of the workings of the brain. We can detect changes in schizophrenia and bipolar disease but we do not understand them very well yet.

Brain disease

We should stop calling them ‘mental’ illnesses. They are brain diseases and can be treated by physical means. Brain disease can take its place alongside heart disease, chest diseases and the like and need not be regarded as a separate entity. Then brain illness will be able to compete for funds in the NHS equally with cardiac disease, cancer, and asthma.

Such a change in the way we think about brain disease will mean that mental illness will lose the terrible shame and stigma some people attribute to it. We all have an interest in this, one in four of us will suffer from brain disease at some time in our lives so if it is not you, there will be someone close to you.

Note:

Descartes

René Descartes (1596-1650) born in La Haye en Touraine, his house is still there. He went to a Jesuit college and to the University of Poitiers. He spent 20 years of his life in The Netherlands and ended it as a tutor to Queen Christina of Sweden where he caught pneumonia in her cold and draughty castle. He famously wrote cogito ergo sum – I think therefore I am.

His development of cartesian co-ordinates allowed algebra and geometry to be linked. His philosophical works were concerned with the nature of truth.