Question: Whom in my life should I tell I have bipolar disorder?
Answer: There's no simple list of people in one's life that should know that somebody has bipolar disorder. This often depends on one's family circumstance, friendships, and work or school circumstances as well. Having said that, it's often helpful for one's immediate family members to be aware of this diagnosis so that they can actually be helpful and supportive-- oftentimes people with bipolar disorder in acute phases of illness can make decisions that they will regret later. And it's important for people around the person with bipolar disorder to be able to tell that person-- look you're not acting like your usual self and you're doing things that you may regret later, what can we do about this.
So it's important for the person to consider sharing this information with their immediate family members and close friends. There may be circumstances in which this diagnosis may play an important role in ones ability to work or go to school and in those cases that person should simply be getting help and going through the right channels so that they can get the stability and the help that they need so that they can perform at their maximum capacity.
The backdrop to all of this though is that having a medical diagnosis is a private affair so there is no obligation to share this with anybody in your life, so the decision should really be only be made on the basis of whether it's going to be helpful to the person with bipolar disorder to share this information with others.