Drugs that increase central nervous system activity, such as cocaine, amphetamines, methamphetamines, and methylphenidate, are classified as which category?

• A. Depressants/Sedative-hypnotics
• B. Stimulants
• C. Hallucinogens/Dissociatives
• D. Cannabinoids/cannabinols

Answer: (B)

When we categorize drugs by their effect on the brain, those that increase central nervous system activity are stimulants. The substances listed—cocaine, amphetamines, methamphetamines, and methylphenidate—raise activity by boosting signaling of monoamines like dopamine and norepinephrine in the brain. Cocaine blocks reuptake of dopamine, norepinephrine, and serotonin, which keeps these chemicals in the synapse longer and heightens neural activity. Amphetamines promote the release of dopamine and norepinephrine and also inhibit their reuptake, further increasing signaling. Methylphenidate mainly blocks dopamine and norepinephrine reuptake, raising their levels. Methamphetamine both increases release and reverses transporter function, flooding the synapse with monoamines. This overall rise in brain activity and alertness is the hallmark of stimulants.

Depressants slow brain activity, hallucinogens alter perception and thinking, and cannabinoids can produce mood changes, relaxation, or other effects without the primary action of broadly increasing CNS activity.