The Body and Mind: Shaping the pain experience

As mental health awareness week ends, it is worth remembering that our mind and body are one.

Hundreds of years ago, a man named Descartes developed the concept of ‘deus ex machina’: god in the machine. His idea was that the soul resides within a tiny gland inside the brain, and is separate from the machine we call a body.

Fast forward more than 300 hundred years, and a philosophical theory was still splitting medicine down the middle well into the 20th century. On the one side there was physical health, examined and scrutinised by a variety of well validated biological tests. On the other there was mental health with, well, none.

As the 21st century progresses, the dividing wall between the ‘deus’ and the ‘machina’ has crumbled. We now appreciate the impact of mental health on physical disease, and that can only be a good thing.

So how does the mind influence the body?

Well this happens to us all the time. Ever got butterflies before an interview? Then you’ve experienced mind control. The fight or flight response releases adrenaline into the blood, and causes our heart to speed up. The increased pulse means increased oxygen flooding round our body, giving us the edge over predators. But this ancient defence is maladapted to the stresses and strains of 21st century life. Job interviews, speeches and first dates aren’t (usually) dangerous, but our body responds just the same.

When we experience chronic stress our mind send signals to our bone marrow. This is where our blood cells are made, and the signal from a chronically-stressed mind encourages an increase in the soldiers of the immune system: white blood cells.

People suffering mental health issues such as chronic stress and depression have heightened inflammatory markers. But what if the mental health problem is linked to a physical disease?

Many physical diseases are chronic. Rheumatoid arthritis for example, involves the immune system attacking the joints, and has no cure. White blood cells invade the joint and release anitbodies and inflammatory molecules called cytokines. This cause inflammation, joint damage, and stimulates nerves to send pain signals to the brain. Rheumatoid arthritis causes disability and chronic pain; both of which can lead to a deterioration of mental health.

So picture the scene: the immune system is attacking the joint and sending alarm bells out for more white blood cells to join the fight. The immune cells are aggravating the nerves, making them send pain signals to the brain. The cytokines released by white blood cells also enter the brain and cause it to become inflamed. The brain inflammation, chronic pain, and stress of living with the condition leads to a deterioration of mental health. The mind then signals the nervous system to instruct the bone marrow to produce more immune cells. And so the cycle continues…

This sounds pretty hopeless, but the fact that the mind can alter the body’s behaviour actually works in our favour.

Patients understand the importance of emotional support, and over the last few years scientific research has been backing this up. Emotional support, mindfulness, and cognitive behavioural therapy are all being shown to improve the psychological wellbeing of patients with physical diseases. These non-pharmaceutical interventions can help break the cycle of mental and physical problems triggering each other.

I am not saying that people should stop taking their medications and switch to mindfulness. These improvements are seen in combination with conventional drugs.

What it does show is that mental and physical health are not separate.

They directly influence each other.

And “how are you?” is the start of a treatment we can all prescribe.