Depression might not be due to low serotonin

For a long time our understanding of depression was that it’s caused by a chemical imbalance in your brain, when it doesn’t produce enough serotonin – the happy chemical.

Serotonin is a chemical that carries messages between nerve cells in the brain and throughout your body. Serotonin plays a key role in such body functions as mood, sleep, digestion, nausea, wound healing, bone health, blood clotting and sexual desire.


major new research review of dozens of studies into this subject area has concluded that depression isn’t necessarily caused by a lack of serotonin.

Negative life events that lower your mood, found University College London academics, who looked at existing overviews of research on serotonin and depression for their umbrella review, which has been published in Molecular Psychiatry.

The review could reshape the way we think about the treatment of depression, said the UCL team

Although other clinicians have said the idea that depression is down to a simple chemical imbalance is already out of date, while stressing that antidepressants remain a useful option alongside talking therapies

The belief that they have a chemical imbalance may actually lead people to have a pessimistic overview of life – believing that it’s out of their control and making them less likely to seek treatment, said the scientists.

“I think we can safely say that after a vast amount of research conducted over several decades, there is no convincing evidence that depression is caused by serotonin abnormalities, particularly by lower levels or reduced activity of serotonin,” said the review’s lead author Joanna Moncrieff, a professor of psychiatry at UCL.

She added: “Many people take antidepressants because they have been led to believe their depression has a biochemical cause, but this research suggests this belief is not grounded in evidence.”

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