Hi Joie! Indeed, people can have both. But I am also a believer that people are like onions. We have layers. At the very core is our biology and our psychology is the layer above. For people with both bipolar and borderline, it is important to treat the underlying biology first, then build on that foundation with the psychology work. You always need a good foundation. I would go further to say our spirit is even deeper than our biology, but we cannot work on that yet :) So we do what we can.