Depression. He accepts and gets help.

Hello Doc, I here for my father, bipolar runs in my father's family i have researched so much about this and I'm certain that he has bipolar disorder. I can't convince him to get help I have tried so much. Last year he started taking medication only after he saw that I was depressed and that I'm taking medication I fought and came out of it and now I want him to get help in any way. He is being very stubborn about it.  His elder sister is taking meds from a very long time, he is close to her but even she can't convince him. My family especially my mother we all are suffering, he has also made bad decisions which lead to his early retiremernt. He's full of energy and speaks alot which is not necessary and gets emotional anytime, argues on all small things, in past he had also harmed himself by slapping himself and gets out of control, has occurred many times kindly advise on how to help him so that he accepts and gets help. Thanks !