Hair testing to assess both known and unknown use of drugs amongst ecstasy users in the electronic dance music scene.
Data on both known and unknown drug use in the electronic dance music (EDM) scene is important to inform prevention and harm reduction. While surveys are the most common method of querying drug use, additional biological data can help validate use and detect unknownunintentional use of drugs such as new psychoactive substances (NPS). We sought to determine the extent of both known and unknown use of various substances in this high-risk scene. We hair-tested 90 self-reported past-year ecstasyMDMAMolly users attending EDM parties in New York City during the summer of 2016 using UHPLC-MSMS. Results were compared to self-reported past-year use. Three quarters (74.4%) tested positive for MDMA, a third (33.3%) tested positive for an NPS, and 27.8% tested positive specifically for one or more synthetic cathinones (e.g., butylone, ethylone, pentylone, methylone, alpha-PVP). Half (51.1%) of participants tested positive for a drug not self-reported, with most testing positive for synthetic cathinones (72.0%), methamphetamine (69.0%), other NPS stimulants (e.g., 4-FA, 56-APB 66.7%), or new dissociatives (e.g., methoxetamine, diphenidine 60.0%). Attending parties every other week or more often, reporting higher-frequency ecstasy pill use, having tested ones ecstasy, and having found out ones ecstasy was adulterated, were risk factors for testing positive for synthetic cathinones and NPS in general. Hair testing appears to be a valuable addition to drug epidemiology studies. Many EDM party attendees-even those who test their ecstasy-are unknowingly using NPS andor other drugs. Prevention information and harm reduction may help reduce unknownunintentional use.