THERE’S a schematic symmetry to John Curran’s intelligent drama. We Don’t Live Here Anymore, based on two short stories by Andre Dubus, deals with two married couples.

Jack (Mark Ruffalo) is the best friend of Hank (Peter Krause). Jack’s wife Terry (Laura Dern) is equally close to Hank’s wife Edith (Naomi Watts). Jack and Hank are both literature professors and aspiring writers stultifying in a small university town; Terry and Edith are homemakers and mothers.

When Hank confidently hits on the vulnerable Terry one evening after a wine-fuelled celebration, it is because deep down he knows that his own wife has been snatching urgent, joyless trysts with his best friend for several months.

This four-way partner swap may sound like a tidy narrative convenience, but there is nothing neat about this tale of marriages in crisis. Showing messy emotional wreckage in unforgiving close-up, the film is coolly observational — it neither judges its characters nor does it try to make excuses for them. That said, Curran and his actors certainly don’t cut the characters any slack.

Jack is weak-willed, moody and self-obsessed — his motives are as much to do with point-scoring against the friend with whom he can’t help but compete and the wife he can’t forgive for her less than perfect housekeeping.

Hank is a serial philanderer who thinks nothing of hitting on a student to reaffirm his alpha-male status and who doesn’t bother to conceal the fact from his wife.

Edith is prepared to destroy her best friend’s marriage by way of assuaging the misery and betrayal in her own relationship. And although she is the most blameless of the four, Terry is nevertheless a difficult character: brittle, highly strung and prone to bouts of weepy late-night hysteria.

They are convincingly flawed and multidimensional characters. But the realism is traded off against any sympathy you might have.

And this is one of the main drawbacks: however mature, however minutely observed it might be, the pain the characters experience stays removed from the audience. Opportunities for empathy are limited. This is a high-risk strategy. Even the arch misanthrope Neil Labute customarily gives us one character slightly less loathsome than the others.

It’s not that the spouses have anything approaching the baroque nastiness of Labute’s characters, but in a way their weakness is just as off-putting.

While they may not be particularly endearing, there is no denying that the performances are uniformly excellent. Ruffalo corners the market in ignoble, oversensitive, slightly hopeless men. Krause — best known forthe TV series Six Feet Under — is effortlessly, sexily jaded. Watts shows the same melancholy intelligence that characterised her performance in 21 Grams.

But Dern is the real revelation. All jagged pain and misery, her face and body twisted by the knowledge that her husband is drifting away from her, Dern is extraordinary. And if she’s an underused actress, perhaps that’s because performances of this intensity are actually quite difficult to watch.