I do agree that it’s probably unwise to discuss illegal drugs here, but there’s something I really need to clarify. MDMA on its own has been shown to be neuroxic, and there are clinical studies examining the effect of pure MDMA on memory.
First, it’s mostly a fallacy that MDMA tablets sold on the street are full of impurities (‘heroin, meth, etc.’) Dancesafe’s GC/MS results at http://www.dancesafe.org/labtesting/ (now discontinued, but old results are there) show that most black-market MDMA tablets are wholly MDMA or one of its N-alkyl analogs (MDA, MDEA, etc.). When tablets are not pure MDMA, the ‘additives’ are usually relatively harmless (caffeine, pseudoephedrine, etc.), or they are drugs that are less dangerous than MDMA. Essentially the only neurotoxic drug that is ever found in MDMA tablets – other than MDMA itself – is methamphetamine. The amounts are rarely high. I should note that heroin, which is commonly believed to be mixed with MDMA tablets, is neither neurotoxic nor orally active. (From a black-marketing point of view, tablets containing heroin are therefore a waste of an expensive resource that would be profitable if sold on its own.)
Second, MDMA itself is widely agreed to be neurotoxic. Ricaurte’s experiments, and those of others in his field, often conducted experiments where animals were given pure MDMA and evidence of neurotoxicity was discovered. While it’s true that studies into the long-term effects of MDMA on memory in humans can’t allow for the fact that the tablets they took were pure, we do have the animal evidence to support the idea that MDMA is largely responsible for any memory deficit that is observed. (Add to this the fact that it’s likely that most of the tablets they took were MDMA.)
Moreover, there is evidence that the breakdown of MDMA by monoamine oxidase leads to toxic metabolites, probably including hydrogen peroxide. MDMA’s chemical structure leaves it wide open to the generation of free radicals which can cause oxidative damage to the brain. This is only one suggested mechanism for the neurotoxicity observed with MDMA (another has to do with its activity on dopamine neurons), but I think it’s chemically sound.
akrako1: The ‘suicide crash’ isn’t some way of the brain reallocating neurotransmitters affected by MDMA. One reason for it is that the neurotransmitters involved in the MDMA high are depleted, and need to be replaced before normalcy can be restored. The other reason is that MDMA permanently inhibits tryptophan hydroxylase, an enzyme required for making serotonin (one of those ‘neurotransmitters affected by MDMA’). With much of the machinery for synthesizing serotonin made inactive by MDMA molecules, much less serotonin is available – and normal amounts won’t be available until the deactivated enzymes are replaced. This is why MDMA users often feel extremely depressed several days after using the drug.
Zaphod7: Mixing alcohol with a drug fairly well-established to be neurotoxic is probably unwise. There is some evidence that the depressant effect of alcohol may alleviate some MDMA-related neurotoxicity. For the most part, if you’re getting reactions like that, there may be something about your biochemistry that makes MDMA use particularly risky. (For example, some percent of the population lacks sufficient amounts of the liver enzyme that breaks down MDMA, and a very small number of people have suffered sudden, acute liver failure after taking MDMA.)
