A substance that increases activity in the body and nervous system.

Definition from Coon and Mitterer's Psychology: Modules for Active Learning, (2009, p. 229)


Stimulants produce behavioral arousal. As with the sedatives and hypnotics, there are a variety of substances, each with a different neural mechanism of action. Examples of stimulants are amphetamine, cocaine, antidepressants, caffeine (the most widely used psychoactive drug in the world), nicotine or tobacco, appetite suppressants, and a variety of exotic plant products. Stimulants vary in strength, legal status, and the manner in which they are taken; however, all stimulants have addictive potential.

Excerpt from Psychoactive Drugs

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