> for MDMA 5 times is already quite at the edge imo

Indeed, but I was speaking of 5 times like 1 LSD 1 mushroom, 1 coke and 1 mdma a year or something, with extremely cautious dosing..

> you can't get honest information about what is responsable

This is really debatable or even not true. There are several website (erowid, r/drugs) with literally thousands of not tens of thousands of reports and experiences of various people, including thoughts on multi-year / multi-decade drug experiences. If you sincerely look for the information there's everything you need