MY FRIENDS DAD IS PYHICO??

Has he really been diagnosed with bipolar? If so maybe his medications need adjusting. If he isn't the 3rd shift is a pretty stressful sift to work he just might be stressed out. It's just to bad if he is taking it out on her. Was she breaking any of the family rules by having people over? Its hard to say without knowing more about it. He should not keep her from school that is a whole other issue he can get in trouble for that by law in most states anyways.