You inherit the ability to have that illness. But there's still some parts we don't understand. For some people, it seems to come out of nowhere. She does know what helps. She mentions medication and making sure you sleep at night, as well as things like monitoring her caffeine intake and getting regular exercise.
Faye can laugh about things now.
I was thinking that the whole episode that so damaged my life is less than one percent of my life. But it tells a tale which reveals the most profound part of your life doesn't necessarily mean the good life you once knew is at an end.