Which substance is classified under Schedule I with no accepted medical use?

Heroin is classified as a Schedule I substance under the Controlled Substances Act, indicating that it has a high potential for abuse and currently has no accepted medical use in the United States. This classification is indicative of substances that are considered the most dangerous and are illegal in any form, reflecting the societal view and scientific evidence about their potential for addiction and harm.

In contrast, morphine is a Schedule II substance, meaning it has accepted medical uses but also has a high potential for abuse. Adderall and lisdexamfetamine are both classified as Schedule II substances as well, used for treating conditions such as ADHD and narcolepsy. Therefore, heroin stands out because of its absence of accepted medical application and its categorization as a Schedule I substance, reinforcing the understanding of drug classifications and their implications in law enforcement and public health.