Which schedule of drugs under the CSA has the highest abuse potential?

Schedule I drugs under the Controlled Substances Act (CSA) are classified as having the highest potential for abuse and are not accepted for medical use in the United States. These substances are characterized by their lack of accepted safety for use under medical supervision, leading to significant risks of addiction, dependence, or other adverse effects.

Examples of Schedule I substances include heroin, lysergic acid diethylamide (LSD), and 3,4-methylenedioxymethamphetamine (MDMA). Because these drugs are perceived to pose a severe threat to public health due to their high abuse potential and the absence of medical utilization, they are strictly regulated and prohibited.

In contrast, other schedules, such as Schedule II, include drugs like morphine or oxycodone that, while having a high potential for abuse, are accepted for medical use and are available by prescription. Schedule III and Schedule IV drugs have progressively lower abuse potentials and include substances with accepted medical applications that often come with fewer restrictions.

Thus, Schedule I is correctly identified as having the highest potential for abuse among the classifications under the CSA.