In my experience - and it clearly does come down to personal experience, it's all we've got once you reject the figures - a hell of a lot of people lie about why they're on benefits. They look OK but they're not.
I know a girl, good looking, funny, clever, hard working, of 22 who claims the lot. Our neighbours have been known to scoff partic as her parents are millionaires (not difficult in London). She's schizophrenic. Not that you can tell by looking at her, and why the hell should she tell you what's wrong with her?