Substances that have a high potential for dependency and withdrawal symptoms are classified as what?

Substances classified as Schedule I or II have a high potential for dependency and can lead to significant withdrawal symptoms upon discontinuation. This classification is part of the Controlled Substances Act, which categorizes drugs based on their medical use, potential for abuse, and safety or dependence liability.

Schedule I substances are defined as having no accepted medical use in the United States and a high potential for abuse, such as heroin or lysergic acid diethylamide (LSD). Schedule II substances, while having accepted medical uses, are also recognized for their high potential for abuse, resulting in severe psychological or physical dependence. Examples include opioids like morphine and stimulants like amphetamine.

The other classifications, such as Schedule III and IV, denote substances with lower potential for dependency. Schedule III drugs can lead to moderate to low physical dependence or high psychological dependence, while Schedule IV substances have a lower potential for abuse relative to the higher schedules. Therefore, while they can still cause dependency, they do not carry the same level of risk associated with Schedule I or II substances.