The Controlled Substances Act of 1970 codified the war on drugs in the United States. The Controlled Substances Act (CSA) criminalized nearly all drugs and introduced stiff penalties for both drug possession and distribution. The CSA categorizes drugs into five schedules, based on how dangerous and addictive the drug is.

The Controlled Substances Act is a federal law, which means it applies to the whole country. However, the Controlled Substances Act is not technically enforced by local law enforcement. The Drug Enforcement Administration (DEA) is the main agency tasked with enforcing the Controlled Substances Act.

Controlled Substances Act Schedule

The Controlled Substances Act breaks down known drugs into schedules, or categories. The schedules rate drugs from least potential for medical use and highly addictive (Schedule I) to less dangerous and lower chance of addiction (Schedule V).

Some examples of Schedule I controlled substances include heroin, marijuana, and psilocybin.

Schedule II drugs may have some medical applications, but are still considered dangerous and likely to encourage addiction.

Schedule III substances like ketamine have a medical use. However, when used outside of a medical setting they can pose a danger and are considered addictive.

Schedule IV drugs have a lower potential for abuse and are often used as prescription medications. Examples include Xanax and Valium.

Schedule V drugs include chemicals like cough syrup with codeine. Schedule V drugs have a lower potential for abuse than those in Schedules I-IV.

Most states have laws on the books that mirror the Controlled Substances Act and use the same schedule system for rating most drugs. However, some states and localities have broken from this tradition and decriminalized certain drugs, notably marijuana and plant-based entheogens.