Controlled substances are drugs and other chemicals that present a high risk of physical dependence or addiction. Often, though not always, they also have accepted medical uses. The government regulates who can possess and use controlled substances, under what circumstances and for how long.
Passed in 1971, the Controlled Substances Act organizes these drugs and chemicals into five categories according to their abuse potential. The correct term for these categories is “schedules.” The higher the schedule number, the lower the abuse potential. For example, Schedule V drugs have the lowest abuse potential, while Schedule I substances have the highest.
Schedule V
Abuse potential for Schedule V substances exists but is very low. Medications included in Schedule V include prescription medications that contain certain narcotics in limited quantities.
For example, certain types of cough syrup contain codeine, which is a narcotic. If they have fewer than 200 milligrams of codeine per 100 milliliters, they qualify as Schedule V medications.
Schedule IV
Schedule IV drugs include sedatives and painkillers. The risk of dependence on or abuse of Schedule IV substances is greater than that for Schedule V but still relatively low.
Schedule III
The potential for abuse or dependence is low to moderate with Schedule III substances. Examples of Schedule III drugs for which abuse is fairly common include anabolic steroids and ketamine.
Schedule II
Schedule II substances can lead to severe physical or psychological dependence and have a high potential for abuse. However, most can also serve the purpose of treating patients. Examples of Schedule II drugs include opioid pain medications, such as fentanyl or hydrocodone. They also include stimulants used to treat ADHD and methadone, which helps wean addicted patients off narcotics.
Schedule I
Like Schedule II drug, substances classified as Schedule I have high abuse potential. However, Schedule I drugs are different in that they have no accepted medical uses. Examples include LSD and heroin.
A prescription for a substance on one of the drug schedules grants a patient access to it for a limited time. However, possession of a prescription drug after the prescription expires is illegal and could result in criminal charges.