High doses of Ritalin lead to similar symptoms such as other stimulant abuse, including tremors and muscle twitching, paranoia,1 and a sensation of bugs or worms crawling under the skin.

One 17-year-old, after snorting crushed Ritalin pills and staying awake for days, went psychotic, killed his parents and severely injured his brothers and sister with a hatchet. A 14-year-old, on Ritalin since he was 7, beat another boy to death with a baseball bat.

Ritalin can cause aggression, psychosis and an irregular heartbeat that can lead to death.