Research Finds There Is Not Sufficient Evidence For The Theory That Depression Causes Lower Serotonin Levels

If you are diagnosed with depression at the hospital, you will be prescribed antidepressants. This antidepressant is a drug that acts on the neurotransmitter system in the brain, and is based on the hypothesis that 'depression is caused by a decrease in the secretion of substances called monoamines such as serotonin and noradrenaline .' However, a research team at University College London has published a renewed treatise that 'this hypothesis has not been proven to be correct' by scrutinizing previous studies.

The serotonin theory of depression: a systematic umbrella review of the evidence | Molecular Psychiatry
http://dx.doi.org/10.1038/s41380-022-01661-0

No evidence that depression is caused by low | EurekAlert!
https://www.eurekalert.org/news-releases/959220

The ' monoamine hypothesis ' that monoamine secretion is associated with mood disorders, anxiety disorders, and schizophrenia was proposed in 1956 in the wake of a clinical experiment conducted by a Swiss doctor . As research on antidepressants continued and selective serotonin reuptake inhibitors (SSRIs) became available on the market in the 1980s, it was thought that 'depression is caused by a defect in neurotransmitter secretion.' became.

Joanna Moncliffe, a psychiatrist at University College London and the lead author of this study, said, 'Antidepressant prescriptions have increased dramatically since the 1990s and are now six adults in the United Kingdom. 1 in 2% of teens are prescribed antidepressants. '

However, although it is said that one in five people with depression actually relieves their symptoms by taking antidepressants, it is clear how the antidepressants work. Is not ... Furthermore, although it is generally thought that 'depression is caused when the amount of serotonin secreted decreases', it has not been proved whether it is true or not, and in recent years there have been some doubts.

A research team led by Moncliffe searched and scrutinized research papers on 'depression' and 'serotonin' in various research archives, and found that serotonin levels or serotonin activity were the cause of depression for decades. Announced that no strong data was found to indicate that.

According to the research team, there was a study that compared the blood serotonin levels of depressed and non-depressed patients and reported that there was no difference. In addition, studies investigating the behavior of neurotransmitter receptors and transporters have shown some indications of the role of serotonin, but the results are inconsistent, the researchers say. It was also found that no large-scale studies comparing the genes of proteins associated with serotonin have been conducted.

'It's very difficult to prove denial, but after decades of scrutiny of research, depression is caused by serotonin abnormalities, especially decreased serotonin levels and activity. I would say that there is no strong evidence of this. '

'We shouldn't tell patients that depression is caused by a decrease in serotonin or an imbalance in neurotransmitters, and we shouldn't convince patients that antidepressants work against yet-proven serotonin abnormalities.' That's the opinion of our research team, 'said Moncliffe.