Many antidepressants may not treat the condition because they’re used to correct a cause of depression that doesn’t actually exist, new research has suggested.
A new review of existing studies concludes that the “chemical imbalance” theory of depression, particularly low levels of serotonin, does not stand up to scrutiny.
Serotonin is a chemical transmitter that appears to play a role in controlling mood and emotions.
Most antidepressants are selective serotonin reuptake inhibitors (SSRIs) and were originally said to work by correcting abnormally low serotonin levels.
However, the overarching study, conducted by researchers at University College London (UCL) and published in Molecular Psychiatry, suggests that depression is probably not caused by a chemical imbalance, and raises questions about what antidepressants do.
The number of people in England taking antidepressants has risen according to NHS figures, with 8.3 million patients receiving them in 2021/22, a 6% increase from the previous year when the figure was 7.9 million amounted to.
The UCL team said 85% to 90% of the public believe that depression is caused by low serotonin levels or a chemical imbalance, but this does not appear to be the case and patients should be made aware of other treatment options from depression.
The review’s lead author, Joanna Moncrieff, a professor of psychiatry at UCL, said: “It’s always difficult to prove a negative, but I think we can safely say that after a tremendous amount of research over several decades, there are no compelling evidence that depression is caused by serotonin abnormalities, particularly lower levels or decreased activity of serotonin.
“The popularity of the ‘chemical imbalance’ theory of depression has coincided with a massive increase in antidepressant use…
“Thousands of people suffer from side effects of antidepressants, including the severe withdrawal symptoms that can occur when people try to stop them, yet prescriptions continue to rise.
“We believe this situation is partly caused by the false belief that depression is due to a chemical imbalance.
“It is high time to inform the public that this belief is not based on science.”
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However, the Royal College of Psychiatrists said patients should continue to take the prescribed medication.
A spokesperson said: “Medication should be available to anyone who needs it. We would not advise anyone to stop taking their antidepressants based on this review, and encourage anyone concerned about their medication to contact them.” to take with their primary care physician.”
Professor Allan Young, director of the Center for Affective Disorders at the Institute of Psychiatry, said of the new study: “The elephant in the room is good evidence of the efficacy and acceptability of serotonergic antidepressants.
“The use of these drugs is based on evidence from clinical trials informing their use for patients.
“This review doesn’t change that.”