Ecstasy puts holes in your brain.

The claim had a scientific peak on 27 September 2002, when Science published a paper by George Ricaurte's group at Johns Hopkins. It reported that "Nonhuman primates exposed to several sequential doses of MDMA" developed severe damage to dopamine neurons, and warned that "recreational MDMA users may unwittingly be putting themselves at risk" of later brain disorders.[1]

In September 2003 the authors retracted the paper. The monkeys had not received MDMA. Nature reported that the group had "accidentally injected monkeys with methamphetamine" from mislabelled vials.[2] PubMed now lists the paper as retracted.[1]

What human imaging does show is narrower than holes. A 2010 PET study of 49 regular ecstasy users found serotonin transporter binding "significantly decreased throughout all cerebral cortices", tied to how much they had used. The same study's MRI scans "revealed no overall regional volume differences between groups".[3] Lower transporter binding is a real finding worth taking seriously. It is a change in a marker, not missing brain tissue.

The retraction travelled less far than the paper. A 2021 study of the 50 largest American newspapers found that of the 26 that covered the 2002 paper, "only 14 (54%) covered its retraction".[4]