A new review shows that there is no convincing evidence that depression is caused low levels of serotonin.
A newly published umbrella review in Molecular Psychiatry is causing quite the stir in psychiatric circles, as it suggests that depression is not likely caused by a chemical imbalance, and thus calls the function of antidepressants like selective serotonin reuptake inhibitors (SSRIs) into question.1,2
“It is always difficult to prove a negative, but 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 lead author Joanna Moncrieff, MD, a professor of psychiatry at University College London (UCL) and a consultant psychiatrist at North East London National Health Service Foundation Trust. “Many people take antidepressants because they have been led to believe their depression has a biochemical cause, but this new research suggests this belief is not grounded in evidence.”
Investigators synthesized and evaluated evidence on whether depression is associated with lowered serotonin concentration or activity, aiming to include all relevant studies that have been published in the most important fields of research on serotonin and depression.
“This review suggests that the huge research effort based on the serotonin hypothesis has not produced convincing evidence of a biochemical basis to depression…” read the review. “We suggest it is time to acknowledge that the serotonin theory of depression is not empirically substantiated.”
As news of the review’s conclusions hit the popular press, critics of psychiatry have praised the findings while the psychiatric community emerged with concerns of their own.
More on this subject will be forthcoming in Psychiatric Times™. In the meantime, if you have thoughts on this new research, write to us at PTEditor@MMHGroup.com.
1. Moncrieff J, Cooper RE, Stockmann T, et al. The serotonin theory of depression: a systematic umbrella review of the evidence. Mol Psychiatry. 2022. Online ahead of print.
2. No evidence that depression is caused by low serotonin levels, finds comprehensive review. UCL News. July 20, 2022. Accessed July 28, 2022. https://www.ucl.ac.uk/news/2022/jul/no-evidence-depression-caused-low-serotonin-levels-finds-comprehensive-review