Serotonin theory of depression

A new umbrella study was published, examining the collective evidence for the serotonin theory of depression, meaning the theory that depression is caused by or correlated with a serotonin imbalance. Systematically evaluating and synthesizing previous studies, the umbrella study finds that there is no evidence for the theory. The study is published open access, and various news media have been reporting on it. The result is quite significant because a common class of anti-depressants (SSRI-inhibitors) are rationalized on the basis of the serotonin theory. Many mental health professionals put forward the theory despite lack of evidence, and many people believe it to be scientifically proven fact that depression is related to a serotonine imbalance, as the authors also write in the discussion.

The official reference to the study and link to it are as follows:

Moncrieff, J., Cooper, R.E., Stockmann, T. et al. The serotonin theory of depression: a systematic umbrella review of the evidence. Mol Psychiatry (2022). https://doi.org/10.1038/s41380-022-01661-0

I find the study valuable and I hope that it will contribute to the erosion of the common belief that depression is intrisically related to a problem with serotonin. Why it takes such a study, after decades of research in serotonin and depression, in order to publicize the „finding“ that there is no significant relationship between the two (other than SSRI-antidepressants), that’s a different story. Or a few.