Family histories are not always clearly diagnosed. That hypothetical uncle you've never met and no one talks about? Unknown mental health flag.
Self-diagnosis of a mental/emotional state that calls for drug-taking is itself a clue that not all is so normal in the individual's mind--or is it something wrong in the world the person wants to relate to better? Who can know but the one supposedly experiencing an unnaccepted state? Observing/deciding/dosing by the selfsame suffering/diagnosing/tripping individual sounds risky, because if the downside is a long future of some degree of insanity, it is only a variety of Russian Roulette.
To allow scientific studies, fund them, possibly create therapies is to also conquer the stigmas involved in substantial ways and that process is tectonically, multi-generationally slow (or impossible).
I suspect your friend had latent psychotic tendencies. Would be interesting to look at family history.
These are powerful drugs that seem capable of both helping and doing harm. They should definitely be used with care, studied, and not abused.
Of course what the war on drugs did was to ban the scientific study of these things and push them exclusively onto the street where they did get abused.