What characterizes a Schedule I drug?

A Schedule I drug is characterized by having a high potential for abuse. This classification indicates that these substances pose significant risks for addiction, physical dependence, and negative health consequences. Schedule I drugs are also noted for lacking accepted medical use in the United States, which further underlines their high potential for abuse as they are not prescribed or utilized in therapeutic settings.

In the context of the other characteristics, accepted medical use is not associated with Schedule I drugs; they are considered to have no legitimate medical purpose. Conversely, Schedule I drugs do not have a low potential for abuse, which would indicate a much safer profile for usage. While access to Schedule I substances is indeed restricted, the defining characteristic that sets them apart from other classifications primarily revolves around the high potential for abuse.