My little brother is about 11 and was just diagnosed with Tourettes. He is starting to take some meds to help him control his ticks and tempers, but my older sister doesn't know and she yells at him all the time. When she does this i see that he starts to tic his head really bad and can't really control although he tries. Would this be a reason as to why he has these tics? And by her yelling does it make it harder for him??