what is ritalin ?, page-7

Ritalin (methylphenidate) is NOT an amphetamine. Like amphetamine however, it is a central nervous system stimulant. In adults, it will have amphetmaine-like effects though it is somewhat less potent than amphetamine or methamphetamine.

Paradoxically, drugs like Ritalin have the opposite action in some kids to adults. It calms them and helps them to organise their thoughts hence their use in ADHD.

Let me know if you need more info.