While I think parent confused dopamine and serotonin, I'd echo this sentiment. In the rave community terms like "blue Monday" or the grimmer "suicide Tuesday" are there for a reason. Many people have a week or even more of 'depression', which thankfully seems transitory for most (although we all know depression can lead to negative feedback loops).
And while caution is definitely needed, the research is mind-blowing. Veterans who have seen and done horrible things find relief in MDMA therapy (in a proper clinic) when nothing else has worked. Powerful stuff, not just a party drug.
Drug companies said that about ketamine, and then they realised they couldn't make much money from ketamine infusions, so they tweaked ketamine to get eskatamine and turned it into a nasal spray. That's patentable and it gives them more money.
The results are pretty poor though.
SSRIs had mind-blowing research, but that was based on very carefully selected test subjects. As soon as it got rolled out to the general population the efficacy drops pretty alarmingly. Some people don't get much benefit from them (SSRIs are a useful, life-saving medication. I am not saying these meds are useless for everyone). See also SNRIs, exercise, etc etc.
And while caution is definitely needed, the research is mind-blowing. Veterans who have seen and done horrible things find relief in MDMA therapy (in a proper clinic) when nothing else has worked. Powerful stuff, not just a party drug.