In this subchapter:
(1) “Controlled Substances Act” means the federal Controlled Substances Act (21 U.S.C. § 801 et seq.).
(2) “Convicted” includes an adjudication under juvenile proceedings.
(3) “Drug offense” has the meaning assigned under 23 U.S.C. § 159(c) and includes an offense under § 49.04, 49.07, or 49.08, Penal Code, that is committed as a result of the introduction into the body of any substance the possession of which is prohibited under the Controlled Substances Act.