Bipolar and/or depression: I'm probably dysthymic, my mom's bipolar (previously thought to be MDD), her father was either depressive or bipolar, and his father (my great grandfather) had severe depression that ended in suicide. We actually have several suicides in the family, none of whom I knew, but only one was medically motivated.

There have also been alcohol abuse problems on both sides of the family (grandfather was a closet alcoholic, mom was an alcohol abuser for several years, dad took to heavy drinking as self-medication before he died), which is the reason I don't drink and have no desire to.