title: Early exposure to marijuana and risk of later drug use.
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Schier
authors.forename: Lewis S
authors.initials: LS
authors.lastname: Nelson
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hoffman
mesh_terms: D006801:Humans; D002189:Marijuana Abuse / Q000150:complications*; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000209:etiology*