The claimed neurotoxicity was based on flawed study that has since been retracted [1]. They mistakenly used methamphetamine instead of MDMA.

[1] https://www.science.org/doi/10.1126/science.1074501

That is one study from 2002. There's dozens of more recent studies on this subject. By neurotoxicity the question is does frequent use of MDMA make it more difficult for your brain to produce serotonin? Research and anecdotal evidence from recreational users point to this being the case.

When your brain becomes dependent on a drug that fries your brain temporarily with serotonin you will not feel as good without the drug. Doesn't sound like a fun time to me.

https://dancesafe.org/drug-information/is-mdma-neurotoxic/#1

On the spectrum from never doing it, to every weekend until your brain stops being able to produce serotonin, how often would you recommend as reasonable?

I'm not claiming I know the long term negative side effects on MDMA use, but like any powerful drug why would I not suspect something that floods your brain with serotonin would not end up in a situation where your brain anticipates the drug and creates an dependency situation where your brain does not produce serotonin in normal levels without it? Anecdotal evidence from long term users in MDMA forums suggest lots of frequent users don't ever feel the same without it.

Bizarre we have gotten to the point where the default is "take powerful drug because no scientist has proven not to in a century long twin study!!"

That is bizarre. Is anyone claiming that?

Long term abuse to the point that "users don't ever feel the same without it" is quite concerning and very problematic, but once or twice seems fine, despite the absence of "a century long twin study".

> but like any powerful drug why would I not suspect something that floods your brain with serotonin would not end up in a situation where your brain anticipates the drug and creates an dependency situation where your brain does not produce serotonin in normal levels without it?

Because this is such an incredible oversimplification of what goes on in the brain. SSRIs also dramatically increase the overall serotonin flux, to the point where if you quit suddenly, the brain is left in a deficit, the effects of which can be quite unpleasant. And contrary to the "serotonin is happy chemical, more serotonin = more better" myth, the net result of all this serotonin is that 5-HT receptors actually downregulate. Ultimately, the result of all these changes is an increase in neuroplasticity.

Blasting 5-HT receptors (eg by LSD, psilocin, etc, and to an extent MDMA) is also shown to increase neuroplasticity.

Neurotoxicity and psychopharmacology are extremely complicated. It's beyond reductionist to say "drug floods brain ergo bad".

You are wrong. Your own link gets a claim to neurotoxicity which is 'backed up' by this very same flawed study:

[1] Hatzidimitriou, McCann, and Ricaurte, “Altered serotonin innervation patterns in the forebrain of monkeys treated with MDMA seven years previously: Factors influencing abnormal recovery”, The Journal of Neuroscience, June 15, 1999, 19(12):5096-5107. Abstract.

The same Ricaurte that 'accidentally' gave excessive methamphetamine to monkeys intsead of MDMA. The same study.

so you'd have no problem recommending indefinite weekly use of MDMA because in your mind no one has proven there's long term negative side effects?

Don't strawman me. I just pointed out your link relies on a totally flawed study.

I recommended nothing, and I didn't say there were no negative side effects. See HN guidelines please.

Your own link says that the axons fairly quickly regrow from any damage, if it occurs at all which is not at all a settled matter, and it further says that large scale studies show no differences between former users and non-users. Again, these claims of neurotoxicity are exaggerated.

...in your mind frequent long term use of MDMA has no negative long term side effects?

Neither of us have any idea of the side-effects of undefined "frequent", "long-term" use, that's my point, and contrary to what you claimed. No serious harm is apparent from the sparse evidence we do have though.

Bizarre logical reasoning. So because no one has completed a 100 year study on a powerful drug the default should be to feel safe using it long term instead of not using it?

And no there's plenty of anecdotal evidence from long term users who never feel the same after frequent use, even after stopping. But again by your logical reasoning because there's no peer reviewed study on humans that sufficiently backs this up people should ignore that.

What's bizarre is how you repeatedly misconstrue someone pointing out that your claims of harm from MDMA are not supported by evidence, into claims that it's perfectly safe to use with no qualifications.

> And no there's plenty of anecdotal evidence from long term users who never feel the same after frequent use, even after stopping.

People who use one drug often use others, and often concurrently. We use science to disentangle these confounders like this.

I have no problem with people advising caution in using powerful drugs, and advising against them fully if they have a family history of mental health issues. I do have a problem when people try to use flawed science to give this caution a false sense of authority.

> And no there's plenty of anecdotal evidence from long term users who never feel the same after frequent use, even after stopping.

Aging is a thing. Most adults don’t “feel the same” after the passage of a “long term” span of time, regardless of their level of substance use.

Do you have any evidence that it does? Sounds like you're trying to straw-man people because you have zero evidence that isn't just straight up fraud.

From personal experience of having done it almost weekly for a long stretch (multiple years), and then quitting cold turkey, it took me a few months to fully land back in reality, but I've since had a successful career as a software developer, with a happy and healthy family life, and that's typical of the people who I knew back them that I've kept in touch with.

Whatever the serotonin generation issues are (and I definitely had them, and that's why I stopped taking it), they seem to recover over time.

Does this imply that Science, similar to drugs (religion, etc), can also distort human perception of reality?

What's next, internet discussion forums? Is anywhere safe??? :)

I do it once a week when I can get it, over long periods. No impairment and it feels fine, no "doesn't feel as good" happening.

(Personal observation, everyone's different though)