Not really a fan of your disclaimer at the beginning. Psychosis isn’t really a long-term effect of psychedelic use at all. It can trigger the emergence of underlying neurological disorders (such as schizophrenia) that present in part as psychosis, but that’s exceedingly rare.
I’d argue the main adverse effects to warn about would be 1) psychological trauma, which can be caused by a challenging experience (bad trip), and 2) HPPD (hallucinogen persisting perception disorder) which, while also rare, can happen and causes constant visual disturbances like shifting or static.
Just played through the whole game and really liked it too, despite the inaccuracies!