Which schedule includes substances that have a high potential for abuse and have no accepted medical use in the U.S.?

The correct response identifies Schedule I substances, which are characterized by their high potential for abuse and lack any accepted medical use within the United States. These substances are deemed unsafe for use even under medical supervision, which significantly differentiates them from those in other schedules.

Schedule I drugs are strictly regulated; examples include heroin, lysergic acid diethylamide (LSD), and 3,4-methylenedioxymethamphetamine (MDMA). Due to the severe penalties associated with their handling, prescribing, and distribution, the federal government places these substances under the highest level of control within the Controlled Substances Act.

In contrast, the other schedules contain substances that either have accepted medical uses (like those in Schedule II and III) or are less tightly regulated and recognized as having a lower potential for abuse (like those in Schedule IV). This regulatory structure is designed to mitigate risks while allowing for the use of necessary medications.