I'm personally excited to see what sorts of new treatments will come out of using psychedelics medically. I've always been on the skeptical side of medical marijuana usage in all but the most extreme cases, but I have a feeling that LSD and psilocybin can really provide mental turning points and help people break out of depression.
Really? A friend of mine had a similar experience to what @ergothus described in their comments. The friend had a biking accident and got stitches. To ease the pain the doctor prescribed Aadvil / Tylenol, but those drugs just caused diarrhea. So he tried edible marijuana[in a legal state] and it helped him a lot through a few weeks of painful recovery without any side effects.
I find miracle claims suspect as well, I don't think marijuana cures cancer.