article_snippet.sent: (THC is the primary psychoactive substance in marijuana.)
article_snippet.sent: 10 diseases marijuana could affect .
article_snippet.sent: With medical marijuana legal in nearly half the states, doctors are increasingly studying what effect the drug has on various ailments.
article_snippet.sent: Under the Controlled Substances Act, marijuana is listed on Schedule 1, meaning marijuana has "no currently accepted medical use and a high potential for abuse.
article_snippet.sent: To backers of reform, marijuana presents a Catch-22:
article_snippet.sent: Marijuana is restricted, in large part, because there is scant research to support medical uses, yet research is difficult to conduct because of tight restrictions.