My best friend's dad is Bipolar...at least everyone assumes he is. He's not officially diagnosed because he refuses to go see a mental health professional. He doesn't believe anything is wrong with him and that there must be something wrong with everyone else. However, he basically has no friends and gets really irritable at a moment's notice for no apparent reason. He's been this way for at least 20 years and his mother was officially diagnosed with it.

Does it sound like Bipolar or maybe something else? Is there any way in particular I could offer encouragement or support to my best friend? She lives on her own and often worries that one of his mood swings could result in violent behavior. There have been a couple small incidents but nothing really huge.