I have both bipolar and borderline personality disorder. As far as I can tell, no one in my family has either, but still. There's likely a genetic component. Also, my partner has borderline as well, so I'm worried that we're both going to pass down the craziness to our children. We both grew up in emotionally abusive households. My partner's gone to therapy, and he has a pretty good head on his shoulders, but I don't. I'm very rash and I will literally scream at the top of my lungs at least once a day.