Ritalin (methylphenidate) and Adderall (dextroamphetamine) both act by causing central nervous system (CNS) and respiratory system stimulation. Ritalin is believed to block the reuptake of neurotransmitters norepinephrine and dopamine whereas amphetamine mixtures like Adderall cause the release of norepinephrine from nerve endings. This increase in neurotransmitters exhibit their effects on the brain, allowing for improved focus and attention span.