Tuesday, 9 March 2010
Does your brain feel ill?
When we have been ill for a little while it is natural to feel "down", isn't it?
A bout of sickness, flu, or a bad flare-up of our chronic symptoms will often lead to feelings of lethargy and depression and we usually find our fellow humans' response to this is: "That's not surprising after being unable to do things normally - I would get depressed about it too!"
But this is a strange Western rationalisation of the brain as separate from the body. Obviously the brain is actually connected to the body, and the brain tissue can become ill as well.
New research has shown clearly that our brains actually respond to infection in the body to make us FEEL ill; it is not just a psychological after-effect of a physical event - the brain makes this happen.
Now some clear research studies have shown the process involved. The innate (initial defensive) immune system produces proteins called cytokines whenever they encounter a bacterial challenge.
This then signals to the brain, then the entire balance of "mini" hormones and different chemicals in the endocrine system undergoes a change. These signals run through the neurotransmitters and alter our mood and behaviour.
There is already enough evidence to show that the root of depression is in something called the subgenual cingulate of the brain.
When researchers watched the subgenual cingulate with an MRI scanner they found that patients who had mild inflammation from a typhoid injection showed activity here. And those who had the largest inflammatory cytokine response had the greatest problems with their mood and a slowing down of their normal responses.
Dr Neil Harrison of Sussex University told the World Service's Healthcheck programme that many different illnesses with a bacterial element and immune response cause this real physical action in the brain:"Cytokines can cross the blood brain barrier but can also bind to nerve endings and be signalled in the brain."
One thing he didn't touch on was why the body might want the brain to make it feel so bad. If your body feels confused, withdraws from social situations, suffers depression and slows right down, according to this research, that's because it is busy mounting an immune response to infection.
So, may I suggest, it might at times be healthy (for all concerned) to stay at home in bed and avoid others, instead of taking some tablets and making a psychological effort to get back in to the swing of things.