What Are Controlled Drugs?

Controlled drugs are substances that are controlled under the Controlled Substances Act (CSA). This act categorizes all substances which are regulated under federal law into “schedules,” depending on how potentially dangerous they are. The schedule the drug is placed under depends on its medical use, its potential for abuse, and its safety or how easily people become dependent on it.

The five “schedules” of drugs, detailed below, should not be confused with the five “classes” of drugs, a different way of organizing drugs according to their main properties. The five classes of drugs are narcotics, depressants, stimulants, hallucinogens, and anabolic steroids.

Careful consideration has gone into this categorization. The control of drugs through law exists to protect people from the harm that these drugs can do. It is based on research from many different sources into the potential harmfulness of the drug, both to individuals and to society.

High Abuse Potential, No Medical Use, Unsafe

Schedule I drugs or substances have a high potential for abuse. They have no currently accepted medical use in treatment in the United States, and there is a lack of accepted safety for use of the drug or other substance under medical supervision.

Examples of Schedule I substances include heroin, lysergic acid diethylamide (LSD), marijuana, gamma hydroxybutyric acid (GHB), and methaqualone.

High Abuse Potential, Medical Use, Severe Dependence Risk

Schedule II drugs or other substance also have a high potential for abuse. They differ from schedule I drugs in that they do have a currently accepted medical use in treatment in the United States or a currently accepted medical use with severe restrictions. Abuse of schedule II drugs may lead to severe psychological or physical dependence.

Examples of Schedule II substances include morphine, phencyclidine (PCP), cocaine, methadone, and methamphetamine.

Lower Abuse Potential, Medical Use, Moderate or Low Dependence Risk

Schedule III drugs or other substances have less potential for abuse than the drugs or other substances in schedules I and II. They have a currently accepted medical use in treatment in the United States. Abuse of the drug or other substance may lead to moderate or low physical dependence or high psychological dependence.

Examples of Schedule III substances include Anabolic steroids, codeine and hydrocodone with aspirin or Tylenol®, and some barbiturates.

Relatively Low Abuse Potential, Medical Use, Limited Dependence Risk

The drug or other substance has a low potential for abuse relative to the drugs or other substances in Schedule III. The drug or other substance has a currently accepted medical use in treatment in the United States. Abuse of the drug or other substance may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in Schedule III. Examples of drugs included in schedule IV are Darvon®, Talwin®, Equanil®, Valium®, and Xanax®. Schedule V Drugs -- Relatively Lower Abuse Potential, Medical Use, Limited Dependence Risk The drug or other substance has a low potential for abuse relative to the drugs or other substances in Schedule IV. The drug or other substance has a currently accepted medical use in treatment in the United States. Abuse of the drug or other substances may lead to limited physical dependence or psychological dependence relative to the drugs or other substances in Schedule IV. Examples of Schedule V drugs are cough medicines with codeine.

US Drug Enforcement Administration. Drugs of Abuse. http://www.dea.gov/pr/multimedia-library/publications/drug_of_abuse.pdf Accessed Jan 8, 2016.