(15, general release, 116 minutes)
Is madness a fitting subject for comedy? PJ Hogan certainly seems to think so, because the Australian director has made mental health the central issue of his latest film.
Hogan is best known for Muriel's Wedding, his exuberant and irresistible 1997 breakthrough comedy.
After Muriel, Hogan went to Hollywood, with mixed success. My Best Friend's Wedding was accomplished stuff, his most recent film, Confessions of a Shopaholic, rather less so.
With Mental, though, the director goes back to basics, back to Australia and back to his favourite actress, Toni Collette, who plays a kind of lunatic savant who transforms the lives of a singularly dysfunctional family.
In an extravagant opening sequence, Hogan's camera soars high over his verdant homeland before zooming in on a suburban back garden, into which a sturdy housewife springs before launching into a spirited rendition of The Sound of Music.
This is Shirley Moochmore (Rebecca Gibney), and in the opinion of her five daughters, Shirley is barking. She's certainly unhappy. Her bombastic husband Barry (Anthony LaPaglia) has pretty much abandoned his family for other women, and politics – he's the town mayor.
Overwhelmed by unhappiness and the pressure of looking after five daughters, at least one of whom appears to have inherited her mental instability, Shirley loses it completely and ends up in the local asylum.
Barry is unhappy at being lumped with the girls, and soon decides to find a babysitter. He spots Shaz (Toni Collette) hitching at the side of the road: she's smoking, dressed like a rock chick, has a dog called Ripper and a very bad attitude, but Barry inflicts her on his girls nevertheless.
Barry's teenage daughter Coral (Lily Sullivan) is horrified, but Shaz turns out to be a blessing in disguise. She gives Coral the strength to believe in herself, diagnoses her sister Michelle's schizophrenia, and sets out to rescue Shirley from the nut house.
Mental is a very strange film, and not at all as charming as it thinks it is. Its tone veers wildly between the kind of cartoonish farce pioneered in Muriel's Wedding, a dour kitchen sink drama, and a cruel farce.
But the film's approach to Michelle's schizophrenia, for instance, is wildly inappropriate, and once the source of Shaz's own instability is revealed, Mental goes off the rails altogether. Shaz's character is more of an idea than a person, and despite Collette's best efforts she never seems tangible, or real.