University College London found that depression isn’t actually contributed to a chemical imbalance in the brain after completing a systematic umbrella review.
A major review of existing studies by University College London (UCL) has shown “no clear evidence” that depression is caused by serotonin levels or activity, led by Professor Joanna Moncrieff.
An “umbrella” review means there wasn’t any new data presented, and that authors review and summarize studies. It’s an overview of existing meta-analyses and systematic reviews.
The study focused on using various ways to capture relevant studies published in important fields of research for serotonin and depression.
It included research, in people, that compared levels of serotonin in the blood between people who are depressed and not-depressed, studies on how well certain protein receptors can bind serotonin when depressed, and studies examining the role of the serotonin transporter.
The review was published in Molecular Psychiatry on July 20th.
For more than three decades psychiatrists believed that depression was caused by low levels of seratonin, but now many researchers realize what they thought they knew about depression is probably wrong.
“The main message of the paper is that scientific evidence accumulated over several decades does not support the theory that depression is caused by a deficiency of serotonin. Since serotonin is the main brain chemical thought to be involved in depression and the one that has been most thoroughly researched in modern times, this means the idea that depression is due to a chemical imbalance is not scientifically established”, said Joanna Moncrieff a Professor of Psychiatry at UCL and a consultant psychiatrist at North East London NHS Foundation Trust (NELFT).
According to UCL’s website, Joanna Moncrieff stated “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.
Chemical Imbalances and Depression
Most antidepressants on the market are selective serotonin reuptake inhibitors (SSRIs) and are said to work by correcting abnormally low serotonin levels.
Moncrieff believes that the ‘chemical imbalance’ theory’s popularity with depression coincided with the vast increase in prescriptions and intake of anti-depression medicines. Antidepressants have risen dramatically since the 1990s, Moncrieff stated, going on to point out that about one in six adults in England and 2% of teens are given antidepressants every year.
Researchers say about 85-90% of the public thinks that depression is caused by low serotonin levels or a chemical imbalance.
Interestingly, the study found that people who used antidepressants had lower levels of serotonin in their blood.
“Our view is that patients should not be told that depression is caused by low serotonin or by a chemical imbalance, and they should not be led to believe that antidepressants work by targeting these unproven abnormalities. We do not understand what antidepressants are doing to the brain exactly, and giving people this sort of misinformation prevents them from making an informed decision about whether to take antidepressants or not”, said Professiosor Moncrieff.
As Moncrieff also urges, do your own research and find what’s best for you if you must take antidepressants. You can find the official review here.