Which term describes a class of drugs that increases activity by counteracting fatigue?

Stimulants refer to a class of drugs that enhance the activity of the central nervous system, leading to increased alertness, energy, and improved mood. These substances work by increasing the levels of certain neurotransmitters, such as dopamine and norepinephrine, which are crucial for regulating attention and arousal. As a result, users often experience reduced feelings of fatigue and heightened levels of motivation and focus.

In contrast, depressants slow down brain activity and can lead to sedation and relaxation, while narcotics primarily relieve pain and can induce feelings of euphoria, but they do not typically enhance activity. Hallucinogens alter perception and can lead to psychedelic experiences, which do not align with the characteristics of increasing activity. Therefore, stimulants are the appropriate classification for drugs that counteract fatigue and boost activity.