The Glass Castle, based on Jeannette Walls’s hit 2005 misery memoir of the same name, could easily accommodate the subheading: “Not a child in the house washed.” Or indeed fed.

As this uneven adaptation opens, Jeannette, one of three neglected children, is calling for food. Her dishevelled mother continues to paint one of her amateur canvasses and instructs the tot to get her own dinner. Inevitably, the child sets herself on fire and awakens in hospital, where a doctor and and social worker hover. Later we’ll marvel that her parents even bothered with medical treatment.

The Walls family, including a distant, powerless mom (Naomi Watts with mussed-up hair), a controlling, alcoholic father (Woody Harrelson) and, eventually, four hungry children, spend years on the road, as dad loses jobs or gets in trouble with the law. They finally settle in whitest-trash Virginia near their even more abusive grandmother.

Destin Daniel Cretton's film cuts between Walls's adult life in 1989, an existence defined by a successful job in New York Magazine, a fancy financial adviser fiance, a luxurious Manhattan apartment, and taxiing past mom and dad (now squatting on the Lower East Side) as they rifle through bins.

The folks continually intrude on her life, with dad explaining that this “isn’t really her” and that her doting husband-to-be needs to go. These blatant attempts at sabotage are treated, by the muddled screenplay, as life lessons to be heeded.

Flashbacks depict the children eating butter and sugar, if at all; saving their mother from being thrown from a window; and being deliberately dumped with sexual predators. There are also scenes – which are a real thing and a metaphor – of Jeanette getting repeatedly thrown in the deep end of a swimming pool until she can swim.

Even Destin Daniel Cretton, director of the excellent Short Term 12, can't quite shore up these contradictions. Accordingly, horrors are accompanied by the syrupy strings of Joel P West's score and the honeyed cinematography of Brett Pawlak. The dilapidated hillbilly huts are artfully distressed. It's misery porn at its most prettily dishonest, but against all odds, Harrelson, Brie Larson and a gaggle of talented child stars render it soapishly watchable.