This is the first honest article I&#x27;ve read on the subject of serotonin and neurotransmitters in years. It basically concludes what very few people seem to be aware of: that we do not know what causes depression or anxiety nor do we know how SSRIs, SSNRIs, or other similar chemicals work. There are, at best, hypothesis, generally untestable. The idea of chemical &quot;imbalances&quot; in the brain is, as it has been since its inception, complete and utter bullshit. The reality is current medical science simply doesn&#x27;t know, the marketers make the rest up, and for some reason, most doctors play along. That&#x27;s how you get to the popular and completely wrong idea that serotonin is the &quot;happy&quot; brain chemical. (Of course, if you&#x27;re aware of the lack of capability in most people to process complex ideas, you could easily guess that such a simplistic idea has to be wrong simply from the number of people who talk about it like it&#x27;s real.)