#1) The serotonin theory of depression has seen way better days. There's simply no way you (or anyone) can say with such reductive certainty that your friend is

#1) The serotonin theory of depression has seen way better days. There's simply no way you (or anyone) can say with such reductive certainty that your friend is "not producing enough serotonin" http://bigthink.com/devil-in-the-data/the-chemical-imbalance-myth http://bigthink.com/devil-in-the-data/the-chemical-imbalance... #2) The novel method of ketamine doesn't really appear to be related to the psychedelic trip itself -- indeed many people are using regular sub-threshold doses of ketamine in their self-designed regimens and seem to be getting good results. LSD and psilocybin treatment seems to be mostly about insights gained during the experience -- much like a supercharged therapy session. Ketamine on the other hand, appears to have some sort of mode of action that isn't about insight and is more about a "brain reset" of sorts. #3) I do agree with you that mental health issues defy reductivity simply because they encompass biological, psychological, and sociological systems that all interact.