REVIEWED - CANDY:THE famous advertising tagline for Bonnie and Clyde - "They're young, they're in love, and they kill people" - could be applied to Candy with a single modification, to indicate that the young lovers in this Australian movie are killing themselves.

When we first meet them, Dan (Heath Ledger), a would-be poet, and Candy (Abbie Cornish), a young artist, appear to be on a natural high rooted in their mutual attraction. When Dan introduces Candy to heroin, the rush is short-lived because it almost kills her, but she is hooked, and they fall into a downward spiral wherein their lives revolve around feeding their habit.

Dan borrows money from an older friend, Caspar (Geoffrey Rush), a chemistry professor and fellow addict who knows he will never be repaid. The young lovers then turn to other options - cadging off Candy's father, pawning their goods - before resorting to desperate measures to fund their next fix.

"When you can stop, you don't want to," Caspar tells Dan. "When you have to stop, you can't." Dan blithely ignores this warning because he doesn't want to know, just as Caspar clearly has not heeded his own advice.

As the movie addresses the inter-dependence of Dan and Candy, and one of them proves weaker than the other when circumstances force them to confront their problem, the film recalls the harrowing cautionary 1962 alcoholism drama, Days of Wine and Roses.

The basis for Candy is a novel by Australian writer Luke Davies, who describes his book as "thinly veiled autobiography". Indeed, there is a persuasive authenticity to the screenplay adaptation on which he collaborated with the film's director, Neil Armfield.

As the relationship between Dan and Candy turns into a love triangle in which the third partner is heroin, Armfield opts for an effectively low-key treatment that is sparing on the histrionics that have been the easy option for many a director tackling out-of-control addiction.

Candy is tough and unflinching in its harsh realism, yet compassionate and honest in dealing with its protagonists. The two leading actors respond with performances of touching tenderness and vulnerability. Cornish, who resembles the young Greta Scacchi, affirms all the promise she showed in Somersault, while Ledger's range and versatility continue to seem limitless.