I have a diagnosis of both.

I had recently found this on the internet:
"A child, adolescent, or adult with predominately AD/HD symptoms noted above with Bipolar Disorder features will present with mood instability, mood swings, mood shifts, intensivity, driven emotionality, etc. This category sees overlapping of both disorders. They often manifest manipulative, demanding behaviors with invincibility [no fear of consequences] and impulsivity. Because Bipolars often have their own agendas (self-centered) they are driven to achieve what it is that they want even in an impulsive manner. They also are selective in their focus, i.e., can attend to what interests them but cannot follow what doesn't, which is a part of the AD/HD. "