Hi ChattyCathy,
Yes, it certainly is possible that you were misdiagnosed. In fact, many adults with ADHD are misdiagnosed (typically, as having depression) because many of the symptoms of ADHD and depression overlap and because many clinicians simply don't have a solid understanding of ADHD in adults. Further, we often see women misdiagnosed because again, clinicians may not understand how ADHD looks in this population.
Still, I would wonder about your past "manic" episodes. Some folks with ADHD can "look" manic when they are instead, very hyperactive. That may have been the case with you. But if the episode was indeed part of a bipolar spectrum, then you would want to stay in close contact with your doctor, especially in the beginning stages of taking Vyvanse (a stimulant) to make sure it doesn't trigger a possible manic episode.
Then again, it might not have been mania to begin with!
I'm glad the Vyvanse is working for you- keep us posted on your progress.
Terry