Bipolar disorder being brought on by a brain injury?

Q: 9 year ago at age 28, I suffered a stroke caused from a blood clot. For the following four years I was off & on different antidepressents for depression yet I felt I was suffering more from anxiety. I was then diagnosed with bipolar disorder. I went into denial over this. I suppose I didn't like the stigma that came along with this diagnosis(I am A medical assistant & should know better.)I researched Bipolar disorder for two years & decided ok, maybe I do in fact suffer from this. So, to get to the point & my question, I was wondering what your thoughts are on Bipolar disorder being brought on by a brain injury? I'm thinking maybe my sister suffers from this also but seeks no help as she is a severe substance abuser and has alienated herself from the family for years, & I think possibly my father does too but he is not one you can convince of these things so I have no professional confirmation. As for me, I can see a slight pattern starting in my late teens to early twentys but nothing much to speak of. That is why I am wondering how much may have been brought on by my stroke which affected my right brain adjucent to the hypothalamus. OK....I've rambled enough but, I've 2 children in their early teens now that I'm wondering if I should worry about. Hence my wanting to know your opinions on brain injuries & bipolor disorder. Thank you very much, Judy

Dear Judy --
You are right.  There is a recognized connection: people with no prior symptoms having them after a stroke or brain injury; and people with prior symptoms seeing them worsen.  Which brain areas are most likely to cause this if injured?  I don't think we know that yet, although I'm sure there are other neuropsychiatrists who could comment on that better than I.   In fact, here's Ron Pies, the mood expert at, on this subject:

Dr. Phelps

Published January, 2001