“…For this study, variables on substance/drug use included the following: (1) regular binge drinking: defined as five or more units of alcohol in one setting “almost every time” or “every time”; and (2) illicit drugs, including those commonly reported in previous studies in Taiwan: ketamine, ecstasy, cannabis, methamphetamine, heroin, FM2 (flunitrazepam), angel dust (phencyclidine), and GHB (4-hydroxybutanoic acid). Following Chen et al, [ 32 ] illicit drugs were categorized as (a) hard drugs, including heroin and methamphetamine, which are classified as Schedule I and II controlled drugs, respectively, in Taiwan, or (b) club drugs, including ecstasy, ketamine, cannabis, FM2, phencyclidine, and GHB, which are classified as Schedule III controlled drugs in Taiwan except cannabis and ecstasy (classified as Schedule II).…”