Welcome!
I may be able to provide you with some insight on the 2. I use MDMA and have also been diagnosed with clinical depression.
I suffered from depression before I ever tried MDMA. My first use (as is common) was AMAZING. It was the best feeling in the world. All of my negative thoughts disappeared (for about 6 hours anyway) .. Every part of my body was on sensory overload. The physical fatigue I had from my depression melted away like a slice of butter on a stack of flapjacks... I was flying high with an even higher outlook on life. Not a care in the world. I couldn't even fathom the thought of being sad or hopeless..
Then came the comedown...
The first few times the transition was smooth.. The euphoria slowly faded away and reality made it's way back in my mind. It took about 24 hours for me to be back to my "old self".. Depression and all..
After having experienced such euphoria after spending so many years feeling like I was drowning actually made dealing with my depression harder. I wanted that feeling back..
I was on edge much more than I had been before taking MDMA.. So naturally, I went in search of more.. For the next few months I was rolling every chance I got.. And with every roll the come down got a little harder..
I eventually ended up pregnant and had to stop taking MDMA, but my depression had gotten so bad that I was put on SSRIs to help relieve the stress I was under trying to cope with it without the MDMA.
After I had my son I waited a few months before slowly weaning myself off the SSRIs so I could take MDMA again..
While the pills had helped me get through my pregnancy, they didn't keep me from wanting to feel the feeling the other drug had given me.. Which was no comparison..
My first dose of MDMA after being off of my meds for 2 months was disappointing.. It wasn't anything like what I had experienced before. I felt good.. But just good.. Not amazing like I had before..
Here I am today.. I have rolled 4 times since, taking 3 months off in between each roll and I've struggled to get back that amazing feeling... I still suffer from depression, although it's nowhere near as bad as it was before.. I'm not taking anything as of now..