http://psy.swansea.ac.uk/staff/parrott/
This guy has also written some interesting papers on it.
Even without any scientific backing at all, there's such a huge amount of anecdotal reports of negative effects following MDMA use, that advising frequent and/or high dose use of this drug as being 'risk free' would go against the harm reduction principles that this site is supposed to uphold.
I think MDMA is a lovely drug, I think it can certainly be used responsibly and safely and a majority of its users do not experience any negatives, I'm sure. I will undoubtedly use it several more times in my life.
I myself, however, as well as many of my closest friends, have experienced lasting issues as a result of MDMA use, in some of our cases relatively 'sensible' use too.
The issues at least in my case were evidently from MDMA, as they had never presented before consumption, specifically presented directly after one session in which I ingested too much resulting in an experience too intense for me (only 180mg at once though, no redose), and faded, albeit very slowly, with prolonged abstinence from MDMA use, and returning to some degree for a lasting period if I were to use again, and this would also slow overall recovery speed.
I know for a fact this was MDMA as I sent it to a lab which I know uses GC/MS to identify samples. Additionally, if my Dutch friend is to be trusted, which he is, the lab he sent it to for purity analysis showed it to be 98.6% pure MDMA.HCl. It's a Canadian-produced batch of safrole derived MDMA and I have always used this source for every MDMA experience bar 1, which was after the negative effects began anyway.
Until we know more facts about what this drug is actually doing to the brain when we use it, I just don't think we should be telling anyone to use it more than a few times a year unless they are willing to accept that they may encounter complications, although they are seemingly rare.
