There was no clear evidence of a link between the strength of drug-control policies in the three nations and the rate of drug use in the three cities. Although the strictness of drug-control policies in Canada falls between those of the United States (the most strict) and the Netherlands (the least strict), the rates of drug use in Toronto generally ranked the highest among the three cities for most of the drugs examined and for both detainees and school dropouts. Also, although drug control in the Netherlands is the most liberal, Amsterdam's drug-use rates never ranked the highest; and for four of nine outcomes (lifetime cannabis and 30-day illicit drug use among detainees and lifetime cannabis use and illicit drug use among dropouts) it ranked the lowest. There were notable similarities among the three cities. In total, over half of study participants drank alcohol in the past 30 days (45-74 percent of detainees and 50-65 percent of dropouts); also, many had consumed five or more alcoholic drinks on at least one occasion in the past 30 days. In all three sites, the majority of participants used cannabis in their lifetime and in the past 30 days. Regardless of site differences in drug use and violence, the percentage of respondents who reported that most of their violent episodes were drug-related (19-28 percent of detainees and 19-24 percent of dropouts) was similar across sites. Data came from interviews with 1,120 adolescents (14- to 17-years-old) and 2 samples (550 detainees and 570 school dropouts). Seven drug-use outcomes and three violence outcomes were compared across sites. 5 tables and 39 references