On its website, the Drug Enforcement Administration provides lists of controlled substances, regulated chemicals and scheduling actions. The documents are not comprehensive and are meant to serve as general reference materials.
Schedule 1 drugs have a high potential for abuse and cannot be legally used for medical treatment in the United States, according to Drugs.com. As of April 2015, marijuana remains on the DEA Schedule 1 list, despite its legalization by some states for personal, recreational or medical use. While a Schedule 2 drug can also be abused, resulting in physical or psychological dependence, it has gained acceptance for use in medical settings with severe restrictions.