1. Dana Plato

Possibly one of the darkest falls from celebrity grace, Dana also starred in Diff’rent Strokes alongside Gary Coleman, as the sweet and pretty Kimberley. What followed her childhood success was a cornucopia of tragic pitfalls in her adult life. Drug addiction, alcoholism, and an inability to properly cope with her typecast career led her not only to appearing in numerous pornographic movies, but even resulted in her robbing a convenience store at gunpoint to take a haul of a couple of hundred dollars. The unfortunate Plato ended up dying of an overdose – suspected initially as suicide – in 1999, having lived the last few years of her life in a trailer park.