2000 Reneman MDMA Memory Study
A Review
Memory disturbances in "Ecstasy" users are correlated with an altered brain serotonin neurotransmission,
by L. Reneman; J. Booij; B. Schmand; W. van den Brink; B. Gunning
Psychopharmacology Vol 148, 2000, 322-324
This look at the MDMA-memory & neurotoxicity issue is an attempt to correlate memory scores with changes to serotonin neural activity. Unfortunately the sample size is so small as to make much extapolation from the data unreliable. This study shows every member of the MDMA-using group to have lower memory scores (word recall - RAVLT) than non using controls.
Obviously if this is reflective of real world users and (as the authors of this and other studies speculate) the MDMA is a causal factor, this is a very concerning result. But this is presented as a pilot study, looking for a direction for future research and cannot be relied upon as providing much data to help answer the question of whether there are real, measureable cognitive effects of MDMA use.
What factors might make these results not extrapolate well?
The data indicating reductions of available serotonin in living MDMA users continues to be concerning. This study asked users for two months of abstinence, which should be long enough to rule out any short-term effects of MDMA user, so this would be looking at either medium or long term effects. The sample size is so small as to make any extrapolations to the general public risky at best.
This look at the MDMA-memory & neurotoxicity issue is an attempt to correlate memory scores with changes to serotonin neural activity. Unfortunately the sample size is so small as to make much extapolation from the data unreliable. This study shows every member of the MDMA-using group to have lower memory scores (word recall - RAVLT) than non using controls.
Obviously if this is reflective of real world users and (as the authors of this and other studies speculate) the MDMA is a causal factor, this is a very concerning result. But this is presented as a pilot study, looking for a direction for future research and cannot be relied upon as providing much data to help answer the question of whether there are real, measureable cognitive effects of MDMA use.
What factors might make these results not extrapolate well?
- Sample size:
This study only looks at 5 heavy MDMA users (average lifetime usage 218 tablets, within a lifetime range of 50 tablets to 500 tablets). Because there is no indication how the subjects were chosen from the general population of MDMA users, it is quite possible that these users are not representative and statistical variation would make this sample too small to have much weight.
- Education:
One confounding factor for extrapolation is that the 5 MDMA users had an average of 2 less years of education than the controls (13 to 15) a 13% difference.
- Data not in article:
As with most of the studies, we are forced to rely on the interpretation of the data made by the researchers instead of being given any of the data tables. Other tests were administered and not mentioned.
- The memory differences between users and non users appear to be huge. With all (?) of the MDMA users scores falling below the bottom of the non users. This seems either Highly Disturbing or wrong. This result alone suggests that the choice of subjects may have more to do with the results than the MDMA use itself.
The data indicating reductions of available serotonin in living MDMA users continues to be concerning. This study asked users for two months of abstinence, which should be long enough to rule out any short-term effects of MDMA user, so this would be looking at either medium or long term effects. The sample size is so small as to make any extrapolations to the general public risky at best.