In my personal experience I have met many young women who swore black and blue they were bipolar (even after being diagnosed BPD), but low and behold after DBT the "bipolar" completely disappeared. So I am very skeptical of those that say one affects the other, In my experience those who say they have both usually only have BPD but dont understand that it is their thinking patterns causing mood shifts. Sure there are some that genuinely have both, but there are many more that use bipolar as an excuse for their behaviour. I know thats going to cause an uproar so I wont come back to the thread. Just expressing my experience.