At minimum, those substances would be very useful in a therapy setting with a trusted therapist. They might also be useful on their own merits, as in, if you have severe depression and eat a bunch of mushrooms maybe you won't be so depressed anymore. Given the current state of anti-depressants, it certainly seems worth a shot.
Hi! You are correct. The first usages of MDMA (the defining ingredient in ecstasy) were in therapy. If you have severe depression (or severe anything really), I would not recommend experimenting without an experienced guide. Think of it like like scuba diving or sky diving: first you learn how with those who already know.
Some say mdma without a guide is still good but you never know . Rick doblin once got a call from a friend who was treating a woman who had depression with mdma and what happened was that she remembered her rape and her being almost murdered ,this memory was complelty blocked by her brain and mdma brought them back . More mdma did not work so Rick doblin decided lsd was better equipped to treat her which worked .
There is a video of her speaking about what happened many years later