The research tracked the psychological responses of more than 650 survivors from the festival. Two-thirds of these were under the influence of recreational drugs including MDMA, LSD, marijuana or psilocybin - the compound found in hallucinogenic mushrooms - before the attacks took place.
"MDMA, and especially MDMA that was not mixed with anything else, was the most protective," the study has found, according to Prof Salomon.
He said those on MDMA during the attack appeared to cope much better mentally in the first five months afterwards, when a lot of processing takes place.
Caveat, the work hasn't been peer reviewed yet. Interesting that enough people were high to even be able to carry out this study.