Here is what Shulgin himself said about MDMA in relation to "brain damage":
"The "permanent brain damage" is based totally on studies done with
experimental animals, with the findings extrapolated to encompass the
human subject. In a simple statement, there have been no studies in man
that have indicated brain damage.
The "holes in the brain" is an even more outrageous deception. These
popular holes are areas in brain scans that appear less active in
attracting radiolabelled agents that are agonists for certain receptor
site areas. The pictures that are shown for comparison are not of the
same person with or without MDMA in them, but of different people, one
of whom has used a lot of ecstasy and the other one without any such
history. The quintessence of this line of mythology is an article that
appeared recently in the Willamette Week. It not only assured the
reader that there were holes generated by serotonin loss, but that they
became flooded with dopamine (the default neurotransmitter) and, being
attacked by hydrogen peroxide, produced rust.
Sorry, drug warriors. No damage, no holes, no rust."[1]
Granted, that was from an interview in 2001. For more recent research see erowid[2], and simonster's post later in this thread.[3]
I would personally be far less concerned about the neurological/mental effect of ecstasy itself than the purity and identify of whatever passes for ecstasy.
This is a very unfortunate effect of the drug war: it makes everyone less safe.
If drugs were legalized, they could be regulated and their purity and dosage could be reliably labeled, just as currently legal drugs are in your neighborhood pharmacy, and people dying because of counterfeit drugs would mostly be a thing of the past.
[1] - http://www.cognitiveliberty.org/shulgin/adsarchive/brainhole...
[2] - https://www.erowid.org/chemicals/mdma/mdma_neurotoxicity.sht...
[3] - https://news.ycombinator.com/item?id=7842632