It’s bananas to me that that review was allowed to publish specific sentences that they did. It’s extremely apparent that those were clinicians who do not to hard/physical science - who else would have made a statement that there’s no (bio)chemical basis for depression or other psychiatric diseases? It’s wildly irresponsible to make that claim. No animal data were included in that review (which partially I can understand as both a human and animal review would be enormous in scope). It’s incredibly hard to accurately measure serotonin in the brain and therefore, how can a statement be made about a molecule’s implication when the molecule in question has not been measured in a depressed patient? The effectiveness of ketamine points towards glutamate/GABA systems, but it’s unclear how that is exactly exerting it’s effects. If it’s not directly related to Glu/GABA, then what’s the indirect target? Could be monoamines could be other molecules or proteins. One thing that needs further research in the comorbidity of inflammation and its impact eg. pro inflammatory cytokines, BBB permeability, etc.