Which substance is incorrectly categorized as a stimulant?

Marijuana is the substance that is incorrectly categorized as a stimulant. It primarily acts as a depressant and psychoactive substance, meaning it typically has calming effects rather than the stimulating effects associated with true stimulants.

Cocaine, ecstasy (MDMA), and Adderall are all classified as stimulants. Cocaine increases alertness and energy, while ecstasy enhances mood and emotional connection and also has stimulating properties. Adderall, which contains amphetamine, is prescribed to treat attention deficit hyperactivity disorder (ADHD) and works as a stimulant that increases focus and attention.

In contrast, marijuana can lead to relaxation and drowsiness, making it more aligned with depressants rather than stimulants, justifying its classification as an incorrect response in this question.