I don't know about you, but I have a hard time believing that heroin and marijuana should be lumped together in the same class of drug. But that is exactly what the DEA does. They list them both as Schedule I drugs, and that is the main reason marijuana is illegal. The DEA website describes these types of drugs as having "no accepted medical use" and having "a high potential for abuse." It also calls them "the most dangerous drugs ... with potentially severe psychological or physical dependence." [continues 406 words]