Is The Bi-polar Disease Hereditary?

My former wife has been diagnosed as Bi-Polar 1 and has been committed almost annually for the past 27 years. My question relates to the probability of our two adult children getting the disease. This disease was passed down from my wife's mother and grandmother. Her two sisters have also been diagnosed as Bi-Polar 1
My daughter is 34 and my son is 37. What do you think?