Anger medication

My Dad diagnosed schizophrenic 46 years ago has deteriorated over last 4 years and has been told that he never had schizophrenia that he has bipolar disorder. He was pshychotic in the beginning, dealed with by Electric Shock therapy, etc.  
He has not has psychosis for 36 years always on different meds.
HE is making my mothers life hell she is a saint and his full time carer, he is so full of ANGER and taking it out on her.

Is that depression?  or what is it.  What medication would help with this.
HE is on high dose epilim and lower dose of Seroquel together.

[FergalEmmanuel]

Anger Management Medication seems like a convenient solution for an anger problem. I have a bias against drugs. I think they must absolutely be a last resort for two reasons they can have nasty side effects and you can build up a dependence on them. There is no medication that directly deals with anger, so the medication prescribed is usually an anti-depressant to help reduce anxiety and stress.