I've had depression since childhood, probably from predisposition as well as my family's negative conditioning and life events. I've had episodes of freedom from depression, but it's dominated my life and caused a lot of failure at work and in relationships, perpetuating more depression. I hate to say, it's gotten markedly worse for me since hormonal changes at 51. But, everyone's biology is different. I don't think it's possible to predict. Depression is also high among the elderly. The experts speak of the strength of one's social network as a factor in how well one weathers depression. Just a few thoughts.