Q:  Cognitive Problems or Mood Disturbances as the Deciding Factor in Diagnosing BP?

back before i was diagnosed as bipolar (in high school) i used to have delusions that i was alternately jesus christ or the devil.  i have told my doctors this, and as far as i can tell from my research, that is one of the main characteristics that differentiates bipolar I from bipolar II, yet i have always been listed as bipolar II. my doctors have told me that this is because i am a rapidian cycler and tend towards somewhat dangerous mixed states rather than a pure depression or mania. which is the deciding factor in diagnosing, the cognative problems such as the delusions, or the mood disturbances such as mixed-mania?

Dear Alex -- 
That's a sophisticated question.  In my view, it's more sophisticated than the diagnostic distinction allows.  There is some evidence that bipolar II "breeds true", i.e. that in a family, bipolar disorder is likely to stay either Bipolar I or Bipolar II.  So in that sense, there may really be a biological basis for the distinction. 

However, your question points out the rather vague territory on the "border" between BPI and BPII.  I'm not very confident of making a distinction between the two in a way that really matches what we might guess is the underlying biology of the conditions.  The easiest "cut point" is the presence of delusions: that is by definition "psychosis", and by definition that's supposed to be Bipolar I.  You clearly understand this and that's why you're asking your question, I understand. 

Your doctors are instead emphasizing the mixed state/rapid cycling aspect of your version of bipolar disorder.  I'm not so sure that really means one should be thinking in "bipolar II" terms, to capture this aspect.  To my understanding of the DSM, the rule book for all this, one can certainly have rapid cycling and mixed states in Bipolar I.  However, I'd agree with your doctors that those phenomena are more characteristic of BPII, in the main.  

But, except for trying to capture something that might really go along with that underlying biology, though, there's not much point in trying to distinguish between I and II.   The treatment is clearly the same (except that some doctors would emphasize using antipsychotics in BP I; I'm less swayed by the presence of "psychosis" in making that choice than some of my colleagues, and as a result I might undertreat the psychosis part sometimes, but the trade-off is that I think I might be using medications that are more specifically targeted at the core problem -- and less problematic in terms of side effects, I hope). 

I hope that gets at some of what you were asking!

Dr. Phelps

Published March, 2004