Drug abuse Yup U.S. National Library of Medicine National Institutes of Health National Institutes of Health Chemical dependency National Institutes of Health National Medical Library National Institutes of Health drug abuse Substance abuse MedlinePlus NIH Medline Plus: Marijuana MedlinePlus Marijuana http://www.nlm.nih.gov/medlineplus/ency/article/001945.htm https://www.nlm.nih.gov/medlineplus/ency/article/001945.htm nlm.nih.gov National Institutes of Health Drug abuse National Institutes of Health National Institutes of Health nlm.nih.gov marijuana