New research has found that serotonin is ‘not the key’ to depression

In the past 12 months the number of people given antidepressants reached 8.3 million – a rise of six percent.

Many are told the condition is fuelled by a chemical imbalance and antidepressants work by increasing serotonin – a “messenger” that carries signals between nerve cells in the brain, researchers said.

But a review of evidence from previous studies found no link between depression and low serotonin.

Study leader Joanna Moncrieff, a professor of psychiatry at University College London, said rising prescription rates were being partly driven by this “false belief”.

Dr Mark Horowitz, a training psychiatrist at UCL, added: “Being involved in this research was eye-opening and everything I thought I knew has been flipped.”