I've recently found out about the suicide of my grandmother, some 20 years ago. Although I never knew her it has cut me kind of deep, and I'd like to ask whether depression can be a genetic thing, since my mother is bi polar and I often have attacks of depression. However, my sister is as bright as a bee (wtf?) and shows no signs of unhappiness at all. Am i more influenced my mum's showings of depression, leading to an environmental effect on my character, or could it be a genetic thing is basically what I'm asking here... Any help?