Q: How can stimulant drugs, such as Ritalin, calm hyperactivity?
A: As any coffee drinker can attest, small amounts of caffeine usually do wonders for alertness, energy and the ability to concentrate. Quaff too many cups of joe, however, and jitteriness and insomnia set in.
Itâ??s the same with Ritalin, Adderall and other stimulant medications now taken by millions of Americans to quell the symptoms of attention deficit hyperactivity disorder (ADHD). At low doses, these drugs calm behavior, boost mental performance and focus attention.
Ramp up the dosage, though, and they act like stereotypical stimulants: impairing thinking, and causing anxiety and even addiction, says UW-Madison psychology professor Craig Berridge.