TLFB). Pictures of forms of MDMA/ecstasy and information about typical dose per pill or powder are provided.8.Ketamine (“ketamine or special K”) is measured in occasions (max use in mg). Pictures of forms of ketamine and information about dosing are provided.9.Gamma hydroxybutyrate (GHB, “liquid G, or Georgia home boy”) is measured in occasions (max use in grams) and pictures about forms of GHB and information about dosing are provided.10.Heroin (“heroin, opium, or junk, smack or dope”) is measured in occasions (max use in mg). Pictures of forms of heroin and information about dosing are provided. Follow-up questions on the TLFB ask about typical route of administration (smoking, oral ingestion, intranasal/snorting, injecting subcutaneous, injecting intramuscular, injecting intravenous), how often they inject heroin, and how often they use clean needles (Novak and Kral, 2011; Hadland et al., 2010; Al-Tayyib et al., 2014).11.Hallucinogens (described as “hallucinogen drugs that cause people to see or experience things that are not real, such as LSD or acid, PCP or angel dust, peyote, mescaline, DMT, AMT, or Foxy”). The ABCD study assesses tryptamine hallucinogens, including lysergic acid diethylamide (LSD), N,N-dimethyltryptamine (DMT), and ayahuasca (Callaway et al., 1999; McKenna et al., 1984; McKenna and Riba, 2015), synthetically produced tryptamine
