Scientists at University College London have conducted an umbrella review, evaluating pre-existing research, and concluded that there is little support for the idea that depression is related to abnormally low levels of serotonin.
Sahanika Ratnayake at Slate writes:
It’s true that the authors of the study are controversial figures, vocal to sometimes vituperative critics of the mental health status quo, leaving heated debates in their wake with each new publication. But the authors’ conclusion has been an open secret within mental health circles for at least a decade. The very public dispelling of this “serotonin model” has also removed a key plank in the widely believed but oversimplified myth of mental illness being caused by a “chemical imbalance.”