Thanks for your response, but I don’t think this is a very fair summary of my piece, nor does it respond to my real point. I contrast the claim (A) “Depression is complicated, but it seems to involve disruptions to the levels of brain chemicals in some important way” with the claim (B) “We understand depression perfectly now, it’s just a deficiency of serotonin”. Then I admit you have amply proven people have made (A) but that far fewer people, and less important, made (B). I think that the supposed counterexamples you provide only prove my point. Going through the first couple: >> “The brain’s serotonin receptors are at abnormally low levels in depressed people and that antidepressants work by increasing serotonin levels in the brain.” But when I look up the press release you are citing, the very first sentence is “Little is understood about how depression makes people feel sad, but neuroscientists do know that the brain chemical serotonin is involved.” Further, this is a study of exactly the sort you originally claim doesn’t exist – evidence for the involvement of serotonin other than the effectiveness of SSRIs. >> “Low serotonin levels are believed to be the cause of many cases of mild to severe depression.” Again, specifies “believed to be” and “many” (rather than all) cases. Again, cites the non-SSRI evidence you claim doesn’t exist. Also, the site appears to be Bristol University Chemistry Department’s “Molecule of the Month” page, which has no relation to any psychiatrist. >> “A current Harvard Medical School special health report, “Understanding Depression”, explains that, “Research supports the idea that some depressed people have reduced serotonin transmission. Low levels of a serotonin byproduct have been linked to a higher risk for suicide.” If you read this report, the very first sentence is “It’s often said that depression results from a chemical imbalance, but that figure of speech doesn’t capture how complex the disease is.” It then goes on to present various theories, including the serotonergic one, but specifies that this is one of many causes and explains exactly what research (beyond SSRI-effectiveness) supports it. Given that your first three examples all support my point, I’m not really sure what you’re trying to do here. I would just recommend to everyone reading this that they look at my blog post rather than getting their impression of it from how it was presented here.