I for one look at it like a cascading serious of events that lead to ultimate sickness. For me it kinda reads like this.
Anxiety/ADHD led me to medicine. I stopped medicine, ate poorly, lost my ability to handle stress. and then got even more anxious, and stressed, and now I'm burnt out. Throw in a couple of business's I had, a few flu bugs, terrible insomnia, intense working out, and terrible though patterns, and now I have full blown AF.