The Depression Trap

Could the number of receptors in your brain determine whether or not you are depressed and how depressed you are? A recent study by the University of Michigan Depression Center suggest that there may indeed be a link.

They took brain scans of patients diagnosed with major depression and compared them to scans of control subjects who were not depressed. One group was tested for 5HT1 receptors which respond to serotonin and a second group were tested for mu-opioid receptors which respond to endorphins (’feel good’ hormones involved in stress responses, pain control and reinforcing rewarding experiences). The test group selected had not previously taken antidepressants.

In both cases they found:

a) Those with depression had fewer receptors.

b) The fewer receptors the more serious the depression.

c) The number of receptors was a good indicator of whether or not antidepressant treatment would be effective.

This suggests that how we respond to life events may be at least in part determined by the receptors in our brain. Whether or not we become depressed, how severe and long lasting our depression is and whether or not we respond to antidepressants may be linked to the number of receptors we have.

So what determines the number of receptors found in the brain? Is it genetic, are we born with it? Is it a result of early childhood experiences? In her book ‘Why Love Matters’ Sue Gerhardt explains how early experiences can have a significant impact on how a child’s brain develops including how many receptors of various types develop.

Equally importantly, can we change the number of receptors in our brain, or are we stuck with what we’ve got? If the number of receptors can change then this might be a possible cure. The scientist don’t specifically cover this in their press release. However, the reason they give for selecting test subjects who had not taken antidepressants was that the antidepressants might have led to more receptors being produced. So this does seem to suggest that the creation and destruction of receptors is possible.

If receptors can be created and destroyed then this also means that the low numbers of receptors may be a symptom of depression rather than a cause. Although once the number of receptors has decreased it seems likely that this would work to re-enforce the depression and perhaps make it worse.

As is so often the case the study raises many new questions. The Michigan team plan to carry out further research and hope that their work will help us to better understand depression. They aim to recruit depressed volunteers who are not taking medication for more brain-imaging studies. You can find out more at www.umengage.org.

What do you think? Post a comment to have your say.