Question: Do I have an increased risk of developing bipolar disorder if I have a parent, grandparent or sibling with bipolar disorder? What about a more distant relative?
Answer: Having a biological relative with bipolar illness definitely puts the person at greater risk of developing bipolar illness.
With that said, the further out one gets from ones own generation -- such as having a great grandparent or a great great grandparent -- the less that genetic vulnerability or heritability might be.
Certain other psychiatric conditions though are also associated with increased risk of bipolar illness, such as highly recurrent depression within one's family, alcoholism, and completed suicides in family members also have been associated with greater risk of developing bipolar illness.