https://www.psychologytoday.com/ca/blog ... n-debunked
The serotonin hypothesis of depression, popular from the 1990s until now, is false, and has been known to be false for a long time, and never was proven to begin with. The norepinephrine hypothesis of depression, which preceded the serotonin hypothesis in the 1960s to the 1980s, also was false, and has been known to be false for a long time, and never was proven to begin with. The same holds for the dopamine hypothesis of schizophrenia, which began in the 1960s and 1970s, and more generally for the “chemical imbalance” metaphor for all mental illness.
The problem is that DSM diagnoses are not biologically valid because they are not scientifically based; they are not based solely on scientific evidence but rather are social constructions of the American psychiatric profession.
Also, the brain just doesn’t work that way. It’s not about “high” this or “low” that. There are many chemicals in the brain interacting with each other in a very complex manner, with negative and positive feedback loops, so that there is no sense at all to say that anything in the brain relevant to any illness has to do with simply having too much or too little of any chemical.
Glory, glory hallelujah! - people are starting to understand.
I could go back and find the argument I had about this very point, but the other guy already admitted he was wrong and is no longer on the site, so gloating doesn't really help anyone. I'm just posting this for educational purposes. I wish this article was mandatory reading for all humans (right after a course in graduate-level statistics).