› reg3aDepartment of Justice ADA Title III Regulation 28 CFR Part 36 ... Illegal use of drugs means the use of one or more drugs, the possession or distribution of which is unlawful under the Controlled Substances Act (21 U.S.C. 812). The term "illegal use of drugs'' does not include the use of a drug taken under supervision by a licensed health care professional, or other uses authorized by the Controlled ...