It’s difficult to work out what writer-director Mike Binder is trying to achieve with this post-9/11 curiosity.

As a bittersweet drama, it’s too safe to be bitter and too erratic to be sweet. And if the intention is to soothe the pain of 9/11, it’s as effective as treating a heart attack with Alka Seltzer.

Luckily, Don Cheadle just about holds the mishmash together as Alan Johnson, a New York dentist who loves his family but feels detached from his wife (Pinkett Smith).

Alan is having further problems with a female patient (Burrows) in that he’s only interested in her oral well-being, while she’s desperate to attend to a certain aspect of his well-being, orally.

As he pesters demure young psychiatrist Angela (Tyler) for free therapy, his old college roomie Charlie Fineman (Sandler) zips by on a motorised scooter.

It’s common knowledge that Charlie’s wife and three daughters were on one of the planes that hit the Twin Towers, and that the poor guy has been an emotional wreck ever since.

Alan resolves to help his former friend upon discovering that he now lives like a lonely, angry teenager, keeping bad thoughts at bay with videogames and loud music and tantrumming whenever he hears something he doesn’t like.

The man-child persona is second nature to Sandler. But while it’s good to see a return to Punch-Drunk Love seriousness, Charlie comes across like a spooky hybrid of Bob Dylan and Rain Man.

Supposedly without friends and removed from all social contact, he plays drums for a rock band. He also has a passion for vinyl LPs despite being permanently attached to his iPod. These are not isolated inconsistencies.

Oblivious to the fact that one man’s cool is another’s boring and geeky, Binder (who takes a small role as Charlie's agent) never misses an opportunity to shoehorn in a clunky reference to his favourite tunes (the title is a track on The Who’s Quadrophenia).

Reign On Me is a paean to the healing powers of Bruce Springsteen - even Charlie’s eventual emotional outpouring is accompanied by the earnest moans and groans of The Boss.

There are some funny moments (mostly from Paula Newsome’s straight-talking receptionist) but the painfully protracted plod towards ‘closure’ couldn’t be more trite if a beardy Robin Williams entered stage left, chanting "It’s not your fault."

You’ll never sympathise with Charlie more than when he asks his most regular question: "Is this session over yet?"

Elliott Noble