Will someone taking adhd meds like ritalin (methylphenidate) need to elevate the dose by the time ? i mean will his body need every period of time higher doses ?

INDIVIDUAL RESPONSE: This varies from person to person. Many people do well on the same dose for years; others may find it nessary to increase the dose. Children may need a medication holiday in the summer ; return to same dose in fall. Some may stay on the same dose year round. Most adults seem constant with dosage.

ADHD: Your prescribing physician can monitor your symptoms to determine need to titrate your meds.