I n a class at college, Christy Carlson Romano was encouraged to think about her “community”. Who were their people, the tutor asked the class, and where did they belong? The answer that popped into Carlson Romano’s head was child actors, but not the ones that went on to have successful grown-up careers. “The ones who were once the shining stars,” she writes in her memoir, “and who are now just trying to find out their places in the world.” Carlson Romano had returned to college after initially dropping out. She had survived sexual assault and toxic relationships, was broke and drinking too much. But before all that, she had been a teenage Disney star. She had made it.

The title of her memoir, Once Upon a Trainwreck, gives you a flavour of where Carlson Romano, 42, is coming from, but what’s most striking isn’t that she goes off the rails (she doesn’t, hugely, compared to other former child stars), but how sensible and mature she is as a child. It’s alarming.…