I would say it's less likely to be financial peril (though no doubt that plays a part, especially when e.g. health insurance is required for some expensive trea

I would say it's less likely to be financial peril (though no doubt that plays a part, especially when e.g. health insurance is required for some expensive treatment), and more likely when a person identifies too much with their job. If you identify too much with your job, losing it is an attack on your ego and it damages your sense of who you are. It's like you died; the role you played in a whole network of social relations is gone. Your status and importance, if you mentally invested yourself in it, is diminished, possibly to irrelevance. You're a nobody. I think this kind of mindset can push someone over the edge.