New Research Says Smoking Marijuana Causes Complete Crohn's Disease Remission In 45% of Patients
In the United States, according to the Controlled Substance Act:
"[W]hen it comes to a drug that is currently listed in schedule I, if it is undisputed that such drug has no currently accepted medical use in treatment in the United States and a lack of accepted safety for use under medical supervision, and it is further undisputed that the drug has at least some potential for abuse sufficient to warrant control under the CSA, the drug must remain in schedule I."
As it happens, marijuana is a Schedule I drug. The government says it has a potential for abuse, which it doesn't, and that it has no accepted medicinal use, which it clearly does.