Speaking of College Journalism on MDMA

October 29, 2009

Hey, here’s another one! The University of Cincinnati school paper has a bit entitled “Ecstasy might be linked to mental deficits” by one Gin A. Ando.

The article basically congratulates some local investigators (Krista Medina and Judith Strong) on the award of this R03 grant to investigate “Effects of SLC6A4, BDNF and Ecstasy Use on Brain Structure in Young Adults“. From the abstract we can see that the investigators are looking at a serotonin transporter (SERT; aka the “reuptake” mechanism of SSRI fame) polymorphism (in the promotor region); such polymorphisms have been associated with a host of pathological conditions. The basic mechanistic hypothesis seems to be that the “short” alleles lead to less expression of the SERT and a chronic compensatory downregulation of serotonin availability in the synapse.
Sounds interesting. You probably know I think the money going forward with Ecstasy / MDMA consequences in human users should back the individual liability horse. For this R03 scale project, I think subject recruitment might be difficult, it is hard enough just to get Ecstasy users and appropriately balanced control groups (including the all-important cannabis-but-not-Ecstasy bugaboo of this area of research). Throw in not one but two (BDNF is the other target) genotypes? Hmm… A good idea, nevertheless.
Anyway, it was a statement in the original newspaper article that raised my eyebrows.

The study will begin recruiting former ecstasy users within the week. Altogether, the project will include 150 people with 50 people in three categories: those who took ecstasy, former marijuana users and a control group. The purpose of the former marijuana users is to
compare any memory loss with those who used MDMA.
“People that have used [ecstasy] have 10 to 20 times the normal memory deficit,” Medina said. “That’s what’s particularly alarming
about it.”

MAPS’ Rick Doblin was all over this in the comments and I have to agree. The human research literature doesn’t support any conclusion of 10-20 fold cognitive deficits in ubpopulations of Ecstasy users from what I can tell. Neither does the animal literature in which the serotonin deficits are controlled and very large in magnitude. If these folks are seeing “10-20 times” the “normal memory deficit” in a genetic subpopulation, that will be something very interesting indeed.
Of course, if the authors’ reference “normal memory deficit” (in Ecstasy users? what task? what control population?) is very small, then a 10-20 fold increase may not be very large at all–the phrasing is still misleading, however.
Unfortunately the publication record from Medina on memory in Ecstasy users is not huge, she seems to have been recently appointed. Looking back to her prior work I found two papers here and here [PMC link]. The latter paper presents statistical gobbledygook common to multivariate human investigations so it is hard to get a feel for the magnitude of deficit in Ecstasy users. The JINS paper, however, shows about a 0.5-0.6 standard deviation difference (relative to the reference data for the memory instrument, California Verbal Learning Test) between Ecstasy users and the marijuana using controls.
I dunno. I am skeptical that a 5-10 standard deviation change in CVLT will be observed in any Ecstasy using genetic-based subpopulation. Especially if compared to the same genetic subpopulations that smoke similar amounts of cannabis as the Ecstasy users.
Either an awkward (mis?) quote or they have some SCHMOKING hot preliminary data…..

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