Thank you for forwarding Dr. Ricaurte's response to our request for a correction regarding his statement in his letter that 1 out of 10 monkeys died, when in his paper he reported that 1 out of 5 monkeys died and 1 out of 5 baboons died.

<< I am consulting with the editor who handled the original paper to determine if and what sort of correction is needed. >>

I am surprised and disappointed that you are considering not printing a correction.

In Dr. Ricaurte's first sentence of his response, he says, "A total of 10 monkeys and 5 baboons received the sequential dosing regimen of MDMA described in our paper." Since the original paper does NOT report that 10 monkeys were treated but only reports that 5 monkeys were treated, out of which I died, and 5 baboons were treated, out of which 1 died, this clearly seems to require a correction. Otherwise, how are readers supposed to make sense of the discrepancy between the information in the paper and that in his letter?

Ricaurte wrote to you, "Our response did not mention baboons, because no questions or comments had been raised regarding baboons, not because we were attempting to "sweep data under the carpet." He also made the Clinton-like lawyerly distinction that baboons are not monkeys. Regardless, our letter in Science questioned "the high mortality in Ricaurte at al.'s primates." While baboons are not monkeys, they are definitely primates. We were unquestionably and obviously commenting on the mortality rate of both monkeys and baboons in his study. At the time we wrote the letter, we didn't know that Ricaurte et al. had treated more than 5 monkeys.

Dr. Ricaurte mentioned that it is inappropriate to estimate mortality rate based on such a small sample of primates. Certainly, estimating mortality rates on the basis of a small sample is not as reliable as a large sample. In any case, we did not try to estimate the mortality rate of primates exposed to his "common recreational dose regimen." What we did do is to compare the fairly reliable information about mortality rates in the population of human Ecstasy users with the mortality rates of his sample of primates. It's plain that the mortality rates of human Ecstasy users are orders of magnitude lower than that of his sample. Whether his sample accurately reflects the mortality rates of monkeys or baboons who receive his dose regimen is anybody's guess and is not something that is worth killing more monkeys and baboons to discover. Nevertheless, in this situation, it is not inappropriate to note the large mortality rate in his sample and to ask the question of whether the doses administered to the primates are actually equivalent to a "common recreational dose regimen" as Ricaurte et al. assert.

Dr. Ricaurte's mentioned the Leah Betts case. As he should be aware, Leah Betts took MDMA but died from hyponatremia, from drinking too much water, an entirely preventable death that is only indirectly related to the consumption of MDMA. In contrast, the monkey and baboon died directly as a result of the injections of MDMA. More importantly, the group of friends who took MDMA at Leah's birthday party are not the only people about which data exists concerning mortality rates. There are millions of other Ecstasy users whose experiences are relevant in developing mortality estimates. In contrast, there are no other primates in the scientific literature who received the same dose regimen administered by Dr. Ricaurte for the Science paper.

I also find it rather astonishing that Dr. Ricaurte claims that the doses he administered to the primates are equivalent to d In his letter, he claims that he didn't use interspecies scaling in his recent studies. In his response, he seems to suggest that his interspecies model is somehow beyond question and that it hasn't been seriously challenged, which it has.

Dr. Ricaurte now speculates that the two animals that were not administered the third injection might have survived the third injection. Perhaps so, perhaps not. How did the gait instability of these two primates that weren't given the third injection compare to the gait instability of the primates that died? Regardless of whether these two additional primates would have died, there is no avoiding the fact that two primates died, as reported in the Science paper, while the Ricaurte et al. letter reports only 1 death in 10 monkeys, with an unexplained extra 5 monkeys treated in the study, with no mention of the death of the baboon.

Ricaurte et al. mention the Downing study in which 1/3 of the subjects experienced gait instability. I helped fund that study, was present when the subjects received their doses, and helped gather data. The gait instability observed was neither serious not substantial and did not indicate that subjects were approaching any life-threatening danger signs.

According to Ricaurte et al.'s paper, there was a 20% mortality rate (2 of 10) of treated primates. According to Ricaurte et al's letter, there was a 10% mortality rate (1 of 10) of treated monkeys, with creates the impression that this is the same ten animals he reported on in his paper. According to Ricau rte's response to our request for a correction, there is a 13.33% mortality rate (1 of 15).

Science has obligation to set the record straight on such a controversial and important matter. To do any less will damage the credibility of Science. Failure to clarify this matter will also be fundamentally unfair to people trying to use the article and letters in Science to estimate the risk that MDMA will cause dopaminergic neurotoxicity in humans, both recreational users of Ecstasy and research subjects in government-approved clinical trials.

Rick Doblin, Ph.D.