Don't subject yourself to the stigma by disclosing your condition to others; don't trust others to be discreet with the information or understand its consequences and ramifications. The disease runs in families; your niece might benefit from your advice. I have a niece who's only in kindergarte but might be susceptible to bipolar disorder in her teens or twenties, and if I see it in her (and I'm still alive) I will tell her all that I have learned and hopefully save her some pain.