Jesus Christ, shekwan, don't suggest thast, for christ's sake.
MDMA has adverse effects on people who have a history of depression; they get none of euphoria, but still get the comedown, and spend three days in agony looking for a way out of life, and flinching at light.
Psylocibin is good, but again, if someone's in a vulnerable mental state and isn't very strong psychologically...STAY AWAY
However, I can only say good things about cannabis medically, especially with regards to ADHD. It's quite probable, from anecdotal evidence, that cannabis actually helps quite a lot in ADHD cases, when taken moderately.