The Act makes deportable a person “who is, or at any time after admission has been, a drug abuser or addict . . . .”[114]  This ground of deportation does not require a conviction.  Under this ground, a noncitizen, including a juvenile, is deportable if s/he is or was at any time after admission a drug abuser or addict, even if s/he is now in recovery.  The test of what is addiction or abuse is extremely broad and may include even casual and sporadic use of “soft” drugs.

[114] INA § 237(a)(2)(B)(ii), 8 U.S.C. § 1227(a)(2)(B)(ii). 

Other

CONTROLLED SUBSTANCES - DRUG ABUSE AND ADDICTION
USCIS released a new medical examination form, dated 04/02/08, which includes specific questions on controlled substance use and addiction (Part 2, Q. 4), and has detailed instructions to physicians about completing these questions (page 6). Counsel must therefore prepare clients for medical exams and interviews by asking, "Have you ever smoked marijuana?" and "Are you in remission? Because if you are not in remission, you are inadmissible and have no waiver (unless you are a refugee or asylee doing AOS)." The HHS guidelines provide that an addict is someone who uses or has used a controlled substance for more than a single, experimental use. I-693 instructions: http://www.uscis.gov/files/form/I-693instr.pdf

Thanks to Deborah S. Smith.