I've had this bipolar diagnosis for years now. In the very beginning I suspected BPD when I was 19, but I was told no. Again I'm reading up on it and see some of those traits in me. I understand that there can be some overlap between BPD and BP. One major issue I have is interpersonal relationships. I can be your best friend one day, but you do something to piss me off, and you're dead to me. Sometimes I can bring you back in, but it can be a toss up. My grandmother found it weird that I can break off relationships so easily. I'm not sure where this comes from, but has made my circle of friends really small the older I get. Anyone else? And would you consider this a BPD trait?