A Controversial New Study on the Cause of Depression Is Being Disputed by Experts

July 21, 2022

A new controversial meta-analysis has argued that our leading theory for depression and treatment is totally off. It has claimed that an imbalance of brain chemistry doesn’t appear to be the cause. Moreover, this review has caused quite a ruckus in the scientific community, with many respected experts stating that it gets a lot of facts wrong.

The writers of this paper have argued that doctors for decades have worked on the belief that low serotonin levels in the brain are the cause of depression. Thus, selective serotonin re-uptake inhibitors, or SSRIs, have been prescribed to people suffering the debilitating mental health issue to address that imbalance.

However, other experts have argued that many folks actually don’t think about depression in such simple terms. As Professor Gitte Moos Knudsen, a professor of neurobiology at Copenhagen University Hospital, stated, “The authors justify the need for such a review by saying that it is a public misconception that depression is caused by low brain serotonin. The main misconception is, however, that depression is a single disease with a single biochemical deficit.” Knudsen then goes on to explain that most people know that depression has many root causes.

Additionally, Dr. Michael Bloomfield, the head of UCL’s Translational Psychiatry Research Group said, “I don’t think I’ve met any serious scientists or psychiatrists who think that all causes of depression are caused by a simple chemical imbalance in serotonin. ] What remains possible is that for some people with certain types of depression, that changes in the serotonin system may be contributing to their symptoms.”

But back to what the scientists actually researched. These folks at University College London undertook the first collation of meta-analysis, systematic reviews, and large-scale studies on the way serotonin affects the brains of depressed people, encompassing the work of hundreds of researchers and tens of thousands of study participants. Their results found “no evidence” to link low serotonin levels to depression.

“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 Professor Joanna Moncrieff.

It’s worth noting that one study has found that artificially lowering a person’s serotonin levels did not produce depression. Nevertheless, as previously stated, many experts don’t believe that depression is solely caused by a lack of serotonin. What’s more, the likes of Dr. Bloomfield still believe that serotonin levels can impact certain types of depression.

The Backlash to This Research

Many other scientists, researchers, and/or experts have come out of the woodwork to critique this new study’s findings. As Dr. Livia de Picker, a member of the University of Antwerp’s Collaborative Antwerp Psychiatric Research Institute, noted, “It is important to point out that this study did not in fact look into the effectiveness of antidepressants directly. Antidepressants with serotonergic activity were already being used effectively for patients with depression prior to the theory of serotonin changes of depression.”

Picker also explained, “There is really no reason to question the effectiveness of current antidepressants even if our understanding of the biological causes of depression moves away from theories focused solely on serotonin.”

Furthermore, some experts believe that serotonin might still play an important role in our understanding of depression. “It is only recently that we have developed the technology to measure serotonin release in the living human brain,” outlined Imperial College London’s Head of the Centre for Neuropsychopharmacology, David Nut. “And in the first study of this type (currently under review) we did find decreased serotonin release capacity in people with depression. So, to dismiss the serotonin hypothesis of depression at this point is premature.”

Professor Allan Young of King’s College London said, “The authors get some details wrong.” Professor Phil Cowen of the University of Oxford said, “What you leave out can be as important as what you put in.” Dr. Bloomfield said that this review “has lumped together depression as if it is a single disorder” in a way that doesn’t make any biological sense.

So, I’m on Antidepressants, What Should I Do?

If you’re someone on meds and this new University College London meta-analysis has spooked you, talk with your GP. They are the expert that knows your situation the best. They can give you personalised advice. They can either assure you or help you explore other options.

What’s more, please don’t just stop taking your meds. Doing so might lead you to become physically ill and might actually hurt your mental health. If your meds are working for you, a lot of scientists believe that meds work.

Read more stories from The Latch and subscribe to our email newsletter.