First of all, ecstacy research in no way effects your Doctor friend's ability to get approved for research. He has to test on animals, well probably because testing that kind of thing on humans first would probably involve killing a few. Ecstacy has already been proven to have very little potential for at least immediate harm. So we know that we aren't going to be ending anyone's life prematurely. Any other risks are just the same as in any reseach study particularly with a previously unliscensed drug.
We don't "KNOW" MDMA is harmful, we have some possible unfortunate side effects but if I was someone who could be cured of something because of the drug, I wouldn't neccesarily worry about the side effects
And anyway its alot of fun.
Oh, and a quick english lesson
Your = something that belongs to you
you're = you are