In other words, there is not a single smoking gun, a solitary rogue gene that works like a binary switch, inevitably...

In other words, there is not a single smoking gun, a solitary rogue gene that works like a binary switch, inevitably causing depression in those unfortunate enough to inherit it. More realistically, all of us will have inherited some of the genes for depression and our chances of becoming depressed will depend in part on how many and their cumulative impact.
https://www.theguardian.com/commentisfree/2018/apr/29/revolution-in-our-understaning-of-depression-will-be-life-transforming?CMP=Share_iOSApp_Other