I'm on a high dose of anti depressants , anti psychotics and lithium and sometimes i involuntry slap myself. why is this?

Evaluate Medications: It would be good to have an evaluation by a psychiatrist to recheck your medications first. You might also want to consult a psychologist after you find out about the medications, and that they're doing the job they should be doing. A psychologist can help you find out if there are some reasons why you are doing things involuntarily. But do get a medication check soon.

See psychiatrist : The psychiatrist will need to do a full history and do an involuntary movement test called an AIMS test.