Did you know that in the US, drugs and other chemicals are classified into 5 distinct categories depending on the drug’s acceptable medical use and its potential for abuse or dependency?  Drugs federally classified as Schedule I substances by the US Drug Enforcement Administration (DEA) are considered to have the highest potential for abuse and for creating severe psychological and/or physical dependence. In addition to heroin, LSD and MDMA (ecstasy), cannabis is classified as a Schedule I substance in the Controlled Substance Act of 1970, which means it has no approved medical usage.