Why does ritalin (methylphenidate) make me grit my teeth more?

Fight or flight: Ritalin (methylphenidate) is a sympathomimetic drug that mimics the changes that the body experiences when it goes on alert and gets ready to defend and flee. We do not need to eat at this time but rather to armor our bodies for fighting. Setting the jaw firmly is protective. Perhaps your dose is too high.

Known As Bruxism: Ritalin, (methylphenidate) along with many psycho stimulants used in the treatment of attention deficit disorder, can cause grinding of the teeth. This is known as bruxism. Clenching of the teeth would be considered the same. It is thought to be caused by changes in Dopamine directly related to the medication. Bruxism can be mild with little discomfort to severe where one's teeth and even jaw bones are damaged.