i m bipolar.  i understand.  i went through the same thing.      my son was at that age, which is no excuse,  he was    hanging around a bad crowd too.  He became hostile,     verbally, abusive, punched a hole in the wall, etc.       when he stayed with friends, i always let him back in     i never turned him away, i had to call the police a few    times,   eventually, he moved out,  and got a job, made    new friends.  Thank God, he s doing better today.       i had to protect myself, and then have patience.      But if he would have been diagnosed with bipolar,     and wasnt taking his meds......then i would get on the    phone and call an ambulance,   i know a hospital isnt    there to condemn, they are there to help, and make sure     people are on the right medication, i think he needs to    be convinced that he needs his meds. by someone other    than you, since he s just in the rebellious stage.     and sounds like he is abusing a substance,  which means     a hospital would be a good place to dry out.  tell him      when you make a decision , its because you love him.         if he becomes physically violent, dont hesitate to call      for help.