Rave Culture: Correlation Doesn't Equal Causation

Synonymous with techno music, empathic love-ins and undue levels of affection, ecstasy (MDMA) is a much-maligned drug, and its treatment by the popular press is either one of derision at its soppy effects or outrage at the human harm it causes.

That MDMA is neurotoxic is clear — rats given huge doses of the chemical show unquestionable neuronal loss — but the specifics are still open to debate. At what dose is it damaging? Does it matter how often it's taken? How long does it take for the damage to repair itself?

Plenty of studies have taken a literal approach to the question of MDMA's effects by testing users’ cognitive abilities. A correlation between MDMA use and cognitive damage has been shown pretty clearly, but no study has attempted to control for the fact that the users surveyed have almost all taken other drugs. A heavy MDMA user is not the same as a heavy polydrug user.

The most recent study tries to clear this up, and is one of the most fascinating.¹ The authors meticulously selected only MDMA users without a history of heavy polydrug use. They did this by taking a hair samples from their volunteers. Hair stores traces of drugs you take, acting as a natural history of their drug use dating back as long as their last haircut.

Here's the trick: All the volunteers, MDMA- and non-MDMA-taking alike, participated in rave culture — that is, staying out 'til 5am at "all-night dance parties" (read that with as stiff an upper lip as you wish). Their MDMA use was the only free variable.

The result? MDMA users don't have statistically significantly lower cognitive function than non-users, except small differences in vocabulary, which the authors point out is usually unaffected by neurological damage in any case. It could actually be that previous studies have simply been confounded by the role of sleep deprivation, part and parcel of the rave world.

The study was small, with only 111 users, but the results should shock anyone who casually condemns MDMA, including ostensibly science-based policymakers who push heavy penalties for its use.

--Henry Stanley

Image Credit: Erich Ferdinand (via Flickr)

References:

1. Halpern, J. H. et al. Residual neurocognitive features of long-term ecstasy users with minimal exposure to other drugs. Addiction 4, 777–786 (2011).

Further reading:

• Observer UK — Ecstasy does not wreck the mind, study claims
• Study author responds to NHS’ flawed conclusions