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Very Recent Article on the Cognitive Effects of Ecstacy Use

BilZ0r

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Evidence for executive deficits among users of MDMA (Ecstasy).
Br J Psychol. 2004 Nov;95(Part 4):457-466.
Fisk JE, Montgomery C, Murphy P, Wareing M.

[Abstract]

This article was posted on PubMed in the last couple of hours, so it must be rather new indeed.

Basically, they use a relatively large sample group: (44 current Ecstasy users, and 59 non-Ecstasy users), which are very similiar demographically:

___________________________Users________Non-users
________________________Mean___SD____Mean___SD__p
Age_____________________21.52__1.66___21.37__1.84__ns
Years of education_________15.66__2.23___15.29__2.16__ns
Ravens Progressive Matrices_48.77__5.94___47.95__5.11__ns
NART____________________28.91__6.88___30.05__5.72__ns


Ravens Progressive Matrices is basically a complete the series, kinda question you'd see in an IQ test. Here is an example.

NART is a reading test. So as you can see, the groups are quite equal as far as age, education, 'IQ' and reading skill.

The using group is composed of quite heavy users (Typical Britons)
Weeks since last used_______10.90
Length of use (weeks)_______183.27
Total number of tablets taken_343.38
Current use: times per week__0.44
Average (tablets per week)___2.14

The two tests were Random Letter generation, and computation span tests. The random letter generation test goes like this: The participant asked to speak aloud a letter each time they heard an auditory signal. Participants are asked to produce letters in a random sequence avoiding alphabetical or well-known sequences They were asked to avoid generating alphabetical sequences and repeat sequences such as AB or BBC. They are also asked to try to produce each letter with the same overall frequency. (It's surprisingly hard). The measure is how many overly redundant letters they used (i.e. if they had to give 260 letters, then they should give each letter 10 times).

The computation span test Participants were presented with a number of arithmetic problems (e.g. 4 + 7=) They were required to solve each problem as it was presented (by circling one of three multiple-choice answers), while at the same time remembering the second digit of each presented problem. At the end of each set of problems the second digits had to be recalled in the order in which they were presented. The measure is how many errors in recall.

Apposed to previous results, using smaller samples, Ecstacy users perfromed just as well as non-users in the Random Letter Generation Task. But, even after trying to account for high cannabis and cocaine user, ecstacy users performed worse on the computation span test.

In their conclusion, the authors state "Because the current study failed to find an Ecstasy-related deficit on the random generation task the available evidence suggests that Ecstasy may not be associated with any substantial impairment in this aspect of executive processing...
...Previous studies from our laboratory have revealed Ecstasy-related deficits in working memory span (e.g.Wareing, Fisk, Murphy, & Montgomery, 2004). However, controls for the use of other illicit drugs were not as extensive as those employed in this study... ...Thus, the current study offers the clearest evidence to date that Ecstasy users are impaired on one specific aspect of executive functioning, updating, and this deficit, at least in part, appears to be independent of the potential effects of other illicit drugs.
"

Unfortunately, this study doesn't look at abstinant users.
The full paper may be found here (102k).
 
Here is another article (tried to attach the whole article but it was too big) an acquintance of mine wrote. He hypothesizes that mdma might effect males more in the dopamineric system and females in the serotoneric system. It makes sense if you think that males have a more vulnerable dopamineric sytem then females ( more parkinson, lesser fine motor skills etc). And females have a more vulnerable serotonin system (L.Reneman showed serotonin neurotoxicity after mdma exposure only in females( of course this could also be due to lesser body weight and lesser consumption of alcohol, with its hypothermic effect, compared to males), females are many more times likely to have depression etc))



Psychopharmacology (Berl). 2004 Mar 18 [Epub ahead of print] Related Articles, Links
Click here to read
Impaired executive function in male MDMA ("ecstasy") users.

Alting Von Geusau N, Stalenhoef P, Huizinga M, Snel J, Ridderinkhof KR.

Department of Psychology, University of Amsterdam, Roetersstraat 15, 1018, Amsterdam, WB, The Netherlands.

RATIONALE. Long-term users of ecstasy have shown impaired performance on a multitude of cognitive abilities (most notably memory, attention, executive function). Research into the pattern of MDMA effects on executive functions remains fragmented, however. OBJECTIVES. To determine more systematically what aspects of executive function are affected by a history of MDMA use, by using a model that divides executive functions into cognitive flexibility, information updating and monitoring, and inhibition of pre-potent responses. METHODS. MDMA users and controls who abstained from ecstasy and other substances for at least 2 weeks were tested with a computerized cognitive test battery to assess their abilities on tasks that measure the three submodalities of executive function, and their combined contribution on two more complex executive tasks. Because of sex-differential effects of MDMA reported in the literature, data from males and females were analyzed separately. RESULTS. Male MDMA users performed significantly worse on the tasks that tap on cognitive flexibility and on the combined executive function tasks; no differences were found on the other cognitive tasks. Female users showed no impairments on any of the tasks. CONCLUSIONS. The present data suggest that a history of MDMA use selectively impairs executive function. In male users, cognitive flexibility was impaired and increased perseverative behavior was observed. The inability to adjust behavior rapidly and flexibly may have repercussions for daily life activities.






Effects of dose, sex, and long-term abstention from use on toxic effects of MDMA (ecstasy) on brain serotonin neurons.

Reneman L, Booij J, de Bruin K, Reitsma JB, de Wolff FA, Gunning WB, den Heeten GJ, van den Brink W.

Departments of Nuclear Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, Netherlands. [email protected]

BACKGROUND: 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) is a popular recreational drug that has been shown to damage brain serotonin neurons in high doses. However, effects of moderate MDMA use on serotonin neurons have not been studied, and sex differences and the long-term effects of MDMA use on serotonin neurons have not been identified. We investigated the effects of moderate and heavy MDMA use, sex differences, and long-term effects of MDMA use on serotonin neurons in different brain regions. METHODS: By means of flyers posted in "rave" venues in Amsterdam, the Netherlands, we recruited 15 moderate MDMA users, 23 heavy MDMA users, 16 ex-MDMA users who had stopped using MDMA for more than 1 year, and 15 controls who claimed never to have used MDMA. We studied the effects of MDMA on brain serotonin neurons using 123iodine-2beta-carbomethoxy-3beta-(4-iodophenyl) tropane ([123I]beta-CIT)-a radioligand that binds with high affinity to serotonin transporters. Density of binding (expressed as a ratio of region-of-interest binding over binding in the cerebellum) was calculated by single-photon-emission computed tomography (SPECT). FINDINGS: We saw significant effects of group and group by sex (p=0.041 and p=0.022, respectively) on overall [123I]beta-CIT binding ratios. In heavy MDMA users, significant decreases in overall binding ratios were seen in women (p<0.01) but not men (p=0.587). In female ex-MDMA users, overall densities of serotonin transporters were significantly higher than in heavy MDMA users (p=0.004), but not higher than in controls (p=0.524). INTERPRETATION: Our results indicate that heavy use of MDMA is associated with neurotoxic effects on serotonin neurons, that women might be more susceptible than men, and that MDMA-induced neurotoxic changes in several brain regions of female ex-MDMA users are reversible.
 
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