Which category includes substances that increase alertness?

Which category includes substances that increase alertness?

• A. Stimulants
• B. Depressants
• C. Hallucinogens
• D. Sedatives

Answer: (A)

Raising alertness comes from substances that boost brain arousal systems. Stimulants do this by increasing activity of monoamine neurotransmitters like dopamine and norepinephrine in circuits that regulate wakefulness, attention, and energy. They can promote alertness by increasing release or blocking reuptake, which keeps these signaling chemicals active longer. That's why you see increased wakefulness, faster thinking, and less fatigue after using stimulants. Classic examples include caffeine and nicotine, and many prescription stimulants as well. Depressants slow brain activity, hallucinogens mainly alter perception and cognition, and sedatives calm or induce sleep; these do not primarily raise alertness.

Raising alertness comes from substances that boost brain arousal systems. Stimulants do this by increasing activity of monoamine neurotransmitters like dopamine and norepinephrine in circuits that regulate wakefulness, attention, and energy. They can promote alertness by increasing release or blocking reuptake, which keeps these signaling chemicals active longer. That's why you see increased wakefulness, faster thinking, and less fatigue after using stimulants. Classic examples include caffeine and nicotine, and many prescription stimulants as well. Depressants slow brain activity, hallucinogens mainly alter perception and cognition, and sedatives calm or induce sleep; these do not primarily raise alertness.