If you ever wondered what it's like to be one of those prurient ghouls who took delight in watching the wretched inmates of bedlam rage against their insanity then look no further.

Based on Augusten Burrough's personal memoir of madness, this warped coming-of-age saga boasts a tour-de-force from Annette Bening...but also leaves a rather nasty taste in the mouth.

She plays wannabe poet Deirdre (artistically pronounced Deer-drah), the pathologically needy mother of Augusten, a bright but deeply troubled young man.

Understandably, Augusten's father Norman (Baldwin) has hit the bottle when faced with an abusive spouse who accuses him of "mistaking creative passion for hysteria".

When he dumps his obnoxious wife, she signs up for therapy with the eccentric Dr Finch (Cox), a charismatic charlatan who is better qualified in embezzlement than psychiatry.

Deirdre then goes a step further and dumps the relatively well-adjusted Augusten with a dysfunctional family so nutty they make a fruit cake look sane.

There's the space-out spouse who survives on a diet of dog food and horror films, the disco-rebel daughter Natalie (Rachel Wood) and adopted son Bookman (Fiennes), an intense drop-out with a splendid zapata moustache.

Up until the half-way mark, this is all fine and dandy with quirkiness rather than a uncomfortable concept of "let's find some freaks then laugh at them" providing the humour.

For instance, the aptly named Dr Cox takes time out in a "masturbatorium" where he, er, relaxes on a leather couch under the portrait of the Queen.

However, after an hour, you're mentally reaching for the buzzer and asking the warder to unlock the door to the padded cell and let you out.

The people here - an emotionally skewed Brady Bunch gone bad - aren't so much damaged as psychologically written off.

Bening is given every opportunity to spin her kaleidoscopic range of neuroses when we could do with seeing a bit more of Baldwin's sympathetic sot to bring some balance to proceedings.

The laughs halt completely when Fienne's predatory biker deflowers a sexually confused Augusten, the fact that he's underage deemed unworthy of comment.

It's a gruelling, overripe trip into the dark recesses of the mind that, to quote the monstrous Deerdrah, "implodes into nothingness".

Tim Evans