I read it that way too. Maybe it should be of instead of for? Not a native speaker, just wondering.
AIDS surviors have "demoralization in them". The psilocybin assisted group therapy is being used for that demoralization.
If you don't speak English, every word will be confusing.
(Native American English speaker here.)
> (Psilocybin-assisted group therapy) for (demoralization) in (long-term AIDS survivors).
The 'for' reads to me as 'to induce', rather than 'to treat'. Changing it to 'to treat' is MUCH easier to read imo