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New research revealing molecular differences between brains could explain why some people are more prone to stress and anxiety, and less responsive to anti-depressants
Scientists in the US found that most anti-depressants raise the level of a neurotransmitter called serotonin in the brain.
However, there is a controlling mechanism within serotonin-producing cells to make sure the brain is not swamped with the chemical.
There are receptor molecules that sense serotonin levels and bring a halt to production when there are excess amounts.
The study found that the brains of some people have more of the “1A-type” serotonin receptors than others.
When these levels are too high, the patients are likely to be unable to respond to anti-depressant “sunshine” drugs.
Study leader Professor Rene Hen, from Columbia University in New York, explained: “The more antidepressants try to increase serotonin production, the less serotonin the neurons actually produce.”
The researchers said the findings on mice could be extended to humans and shed light on why half the people who are prescribed anti-depressants find the pills do not work.
Copyright Press Association 2010