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Q&A: Is cannabis a “gateway drug”?
What is the evidence on cannabis as a gateway drug?
Animal studies
動物実験。
Overall, animal studies are mixed regarding evidence of a gateway effect.
結局のところ、動物実験結果はゲートウェイ効果の証拠について相反する結果がある。
Epidemiology
Observational studies may demonstrate associations, but these do not necessarily reflect causal relationships.
Epidemiologic studies have observed a similar sequencing pattern of substance use initiation among youth cohorts, for example in the United States and New Zealand. Among people who ever used cannabis in the United States, 44.7% had ever used another illicit drug.
流行病学調査でアメリカとニュージーランドのヤング層を対象に薬物使用の始める順番のパターンを観察した、アメリカでカンナビスをこれまで使用したことのある人々の中で44.7%が違法な薬物をそれ以前に使用したことがあった。
Regarding initiation of use, use before age 18 compared with later initiation has been associated with the use of other substances (sedatives, opioids, and hallucinogens). Also, frequency of use before age 17 shows a dose-response relationship with other substance use.
使用開始時期について考えると、18より前に使用した者はそれより後に使用した者にくらべて他の薬物(鎮痛剤、オピオイド、そして幻覚剤)の使用と関連していた。また、17歳より前に乱用していたものは他の薬物使用と密接な関係があった)
A recent longitudinal study of youth substance use trends in the United States from 1976 to 2016 found that cannabis is replacing alcohol and tobacco as the first substance used, but did not analyse subsequentt drug use. However,adolescents that attempted cigarette smoking remained at an increased risk of subsequent cannabis use.
Research in Vancouver, Canada examined the association between cannabis use and initiation of injection drug use among 481 street-involved youth involved in a prospective cohort study. In a model adjusted for other individual characteristics and drug use patterns, the authors found that daily cannabis use was protective against injection initiation.
While it is evident that cannabis use may be associated with other substance use, experts believe that several relationships are involved among social, genetic and environmental factors, which makes understanding the gateway hypothesis complex.These may include adverse childhood experiences or social influences among those who use substances.
http://www.greenzonejapan.com/2018/11/16/police_1/
http://www.greenzonejapan.com/2018/11/24/police_2/
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