They have always known that bipolar is hereditary - her husband and his three siblings all have mood disorders of one kind or another.  My sister has been doing some research and is scared by some of what she is learning.  According to this article "there is a 25% chance that the child of a bipolar parent and non-bipolar parent will develop the disorder."  That seems like a pretty simplistic Mendelian genetic ratio to arrive at so I'm not sure where that number comes from, but there is clearly a genetic correlation.  More alarming are the statistics for suicide.  According to wikipedia "the annual average suicide rate in males and females with diagnosed bipolar disorder is 10 to more than 20 times that in the general population" and somewhere between 18-25% of people with bipolar disorder commit suicide.

My sister is alarmed enough about this that she is questioning whether they should have a biological child and she wants to look into adoption.  Her argument to her husband is "you know exactly how hard it is, would you want your child to suffer like you have?  Would we want our child to be so much more likely to want to die because they are so miserable?"  His feeling is that by saying you don’t want a biological child in a way you are saying that your genes are not good enough to pass on, that he would be better off not being born and his parents should have adopted a child instead.

This is a very sticky ethical area to me.  I can see both of their points.  I find myself learning to my sister’s side.  Obviously you don't want your child to have to go through something so difficult - none of us want our children to suffer.  But where do you draw the line?  If your whole family is obese should you adopt so as not to pass on those genes?  My Dad is an alcoholic and my Mom died of cancer - my kids carry some of their genes.  Everybody has some genetic traits in their family they might be better off without.

What do you think, MotherTalkers?  Would you want to take a chance on passing on mental illness to your child?