I have not had any experience with SSRIs and MDMA; but I am scripted to take two, 150mg doses of bupropion (wellbutrin) daily (it is a DA and NE reuptake inhibitor). Since I started taking the bupropion about 3 months ago I have used MDMA ~6 times. Two of those experiences (first and third) I kept up my usual doses of wellbutrin; the first experience I even took my PM dose of wellbutrin while I was already rolling. For the other four experiences, I stopped taking my wellbutrin about 48hrs prior to when I planned on rolling and did not take any more of it until a good 24hrs after the MDMA faded.
The results were interesting. Both times I maintained my intake of bupropion I still rolled hard; but once I was done rolling (normally by the next morning) my heart rate stayed abnormally high (140BPM-175BPM) while just sitting on a couch in a state of rest. I experienced over 48hrs of an uncomfortably elevated heart rate and an exceptionally prolonger wait to become tired after the first time I used MDMA while taking my wellbutrin. The effects were similar the other time I stubbornly took my bupropion despite my plans to use MDMA soon. I rolled hard, came down psychologically; but then I was kept awake for another day or so by a pounding, rapid heart beat and all around 'cracked-out' sensation that I never normally experience with clean MDMA.
I hated being layed-up all dizzy, weak, and frequently involuntarily twitching for a day or so after rolling. I figured the bupropion, as a DA/NE reuptake inhibitor, might have been causing my dopamine/norepinepherine/epinepherine levels to stay elevated long after the MDMA had worn off and causing the nasty side-effects. So now I create a window of time around the night(s) I plan on taking MDMA during which I skip all of my wellbutrin doses. Since I have put that plan into action I haven't experienced any of the nasty after-effects described above so I figure bupropion must have *some* interaction with the effects of ecstacy.