Disclosure: I'm a psychiatrist, and find this "hot take" to be a drive-by shooting on a strawman, but whatever. A good collection of reactions to this article:<p><a href="https://www.sciencemediacentre.org/expert-reaction-to-a-review-paper-on-the-serotonin-theory-of-depression/?fs=e&s=cl" rel="nofollow">https://www.sciencemediacentre.org/expert-reaction-to-a-revi...</a><p>>Prof Gitte Moos Knudsen, Professor of Neurobiology and Chair of Department of Neurology and Neurobiology Research Unit, Copenhagen University Hospital, Denmark, said:<p>>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. Today, it is largely accepted that depression is a heterogeneous disorder with potentially multiple underlying causes. The review aims to uncover existing evidence for a serotonergic deficit, but the studies included in the review use methodologies that only generate proxies for the real question which is if synaptic 5-HT concentration and release are altered in (subsets) of patients with major depression.<p>>Prof Phil Cowen, Professor of Psychopharmacology, University of Oxford, said:<p>>I studied the role of serotonin in people with depression for three decades and I’m broadly in agreement with the authors’ conclusions about our current efforts, though I lack their adamantine certainty. No mental health professional would currently endorse the view that a complex heterogenous condition like depression stems from a deficiency in a single neurotransmitter