When Ritalin is prescribed to children and teens, it's to treat Attention Deficit Disorder (ADD) or Attention Deficit Hyperactivity Disorder (ADHD). What some people do, though, is take the Ritalin, crush it into a powder, and either snort or inject it.

It makes the effects of the drug much more powerful. Taking Ritalin when it has not been prescribed to you, and taking it in such an intense way, can cause serious headaches, anxiety, paranoia, and delusions. Paranoia is when you think that everyone is talking about you or out to get you. Delusions are things that you think are real when they're not--like seeing someone appear in front of you and then disappear, or hearing voices when no one's there.