Q:  Bipolar & Schizophrenia Overlap - Recent Articles?

My wife has been diagnosed with Bipolar I (Mania; Severe with psychotic features). I wonder if the risk of Schizophrenia for my kids is going higher than the average (1%). I have no Bipolar and Schizophrenia in my family history (at least three generations excluding me). My wife has no Schizophrenia in her family history. My wife's father had alcohol problem and killed himself, so perhaps he had mood disorder.

I read a Japanese book chapter (Kanba and Kawamura 1999) that indicates "Heavy Bipolar and Schizophrenia occur in the same family in many cases". They did not provide any references. I want to know if there are any recent papers that support Kawamura's paper.



Dear H' -- 
The risk for some illness with mood features and psychotic features, in your children, will be higher than it would be for people with no such family history, that's unfortunately true. But the risk should be confined to a risk for these features, not "schizophrenia" as such.  Current genetic research is showing a large overlap between "schizophrenia genes" and "bipolar genes" so that the distinction between the two conditions, at least at the level of genetics research, is starting to break down. I think that probably explains the finding that you were reading about in Kanba and Kawamura. For current research on this overlap, see the work of Nick Craddock in Britain (e.g. this article, where in the lower part of the abstract you'll see this theme emphasized). 

That makes answering your question harder, because it suggests that the question is more complex than "this illness, or that illness" -- they're related and maybe even different versions of the same thing at one level.  As for the risk to your children of some version of bipolar disorder, see the essay on Risk to your Kids for a summary of research on "how much risk?" 

Dr. Phelps

Published October, 2005