Tony Slattery was a star comedian and actor who disappeared into a spiral of mental health and addiction problems. A new documentary reveals the childhood trauma at the root of his unravelling – and why the Catholic Church must shoulder the blame

One of the strengths of the Church, it is often said, is that it moves in decades not years, and so avoids getting swept up in society’s passing fads. Such stately progress, though, can make it slow, even reluctant, to react to what is going on in front of its nose. The clerical abuse scandal is a prime example.

Three decades after reports first appeared in public of priests preying on youngsters, only now does the Church seem to be starting to face up wholeheartedly to the extent of the damage done – to its reputation, to its mission and, most importantly of all, to those who were the victims of predatory clerics. If anyone remains in any doubt about how the trauma of such horrific crimes reverberates ever after in the lives of survivors, What’s The Matter With Tony Slattery? (21 May) in BBC2’s Horizon documentary strand should not be missed.

There was a time in the 1980s and early 1990s when the good-looking, clever, energetic but ever so slightly edgy Slattery was seen everywhere: on Channel 4’s improvisation comedy show, Whose Line Is It Anyway?, which ran from 1988 to 1998; on the West End stage in Me and My Girl and Neville’s Island, which bagged him an Olivier nomination; and on the big screen in The Crying Game, Carry on Columbus and Peter’s Friends, co-starring with his old pals from Cambridge University Footlights, Emma Thompson, Hugh Laurie and Stephen Fry (who crops up, too, in this new documentary).