Which drug is categorized under Schedule I substances?

Heroin is categorized as a Schedule I substance under the Controlled Substances Act. This classification indicates that it has a high potential for abuse, has no currently accepted medical use in the United States, and lacks accepted safety for use under medical supervision. Schedule I drugs are considered the most restricted category, which is why heroin fits this classification.

The other substances mentioned, such as morphine, cocaine, and diazepam, are placed in different schedules based on their therapeutic use and potential for abuse. Morphine is a potent opioid with recognized medical uses and is classified as Schedule II. Cocaine, although it is a powerful stimulant and has a high potential for abuse, is categorized as Schedule II due to its medical applications as a local anesthetic. Diazepam, used primarily for anxiety and as a muscle relaxant, is classified as Schedule IV, representing drugs with a lower potential for abuse relative to higher schedules. This classification system helps regulate the use of substances based on their risks and benefits.