Can Danny Boyle once again capture the national mood with T2 Trainspotting?

Renton, Sick Boy, Begbie and Spud are back.

Danny Boyle is an entertainer, as opposed to an artist, but he can be credited with two decisive moments of British cultural unity, however fleeting or cosmetic they may now appear to have been. The more recent was the opening ceremony of the 2012 London Olympics, which brought the country together with images invoking the NHS, Mary Poppins and the Industrial Revolution. Before that, Trainspotting, his buzzy 1996 adaptation of Irvine Welsh’s novel about Edinburgh junkies, distilled into cinema an edgy energy associated with Britpop and New Labour. The question now is whether its sequel, T2 Trainspotting, has anything to say about Britain at its most fragmented.

It begins, as its predecessor did, with the running feet of Mark Renton (Ewan McGregor), except that now his trainers are pounding the treadmill at a soulless gym rather than on the sweeping streets of Edinburgh. After hotfooting it at the end of the first film with his friends’ share of the loot from a heroin sale, Mark decamped to Amsterdam. Now he has returned to find that the old gang isn’t doing so well. Spud (Ewen Bremner) is back on smack. Begbie (Robert Carlyle) is out of prison and looking for revenge. Simon the cokehead (Jonny Lee Miller), formerly known as Sick Boy, is running a tumbleweed pub on a wasteland.

“The great wave of gentrification has yet to engulf us,” he says grimly. It’s one of the film’s running jokes that the only additions to the landscape are towers of scrap metal; these addicts are now steeped in a different sort of junk. Simon isn’t thrilled to see his old thieving chum; in an attack with a nice air of cultural specificity, he tries initially to drown him in Irn-Bru. But they are soon strolling laddishly together down memory lane. Simon’s Bulgarian associate Veronika (Anjela Nedyalkova) is bemused. “Where I come from, the past is something to forget,” she says. That rather sums up these old Trainspotters, with their self-sabotaging inability to move on from sentimentalised glories and stubborn grievances. How’s that for a comment on modern Britain?

For all that Spud is the group’s laughing stock, he also represents the clearest chance of escape. Encouraged by Veronika to write down his wheezing stories in his own vernacular, he acquires what the others don’t have: self-knowledge, objectivity, even peace. (He’s a Scot but he’s also clearly Welsh – Irvine Welsh, that is.) The electrifying Bremner, authentic emotions playing on his cartoonish features, keeps the film from sinking entirely into the doldrums.

There’s a thin line between depicting nostalgia and succumbing to it, and T2 Trainspotting isn’t always on the right side. There’s no shortage of familiar tableaux (figures stock-still on an empty train platform, Renton grinning maniacally through a car windscreen at the driver) and effects (extreme low and high angles, exaggeratedly cavernous sets). An updated version of the “choose life” monologue, shoehorned into the script, doesn’t count as progress, any more than the use of distorting optical effects associated with Snapchat. And it’s a backwards step for women this time. Veronika’s high point is wearing a strap-on. Mark’s old flame Diane (Kelly Macdonald) gets one brief scene. Shirley Henderson, as Spud’s ex, has a single line. Having proved in Trance that he can exploit women, Boyle shows that he can neglect them, too.

Trainspotting was hardly profound, but at its core was the subversive suggestion that the junkie life was every bit as conformist as the normality it appeared to reject. The new film doesn’t have that inbuilt contradiction. John Hodge’s screenplay, adapted partly from Welsh’s book Porno, insists that nostalgia is a trap, but Boyle has framed that argument in a movie that serves up the greatest hits with minimal remixing – a woozy drug trip, nonsensical in plot terms, is thrown in for old times’ sake.

It would have been far better if the film had broken stylistically with the past, like another sequel with a similar title. Terminator 2: Judgment Day, known informally as T2, rejuvenated a successful idea by changing the rules and even realigning the main character in a spectacular case of “it ain’t broke, but let’s fix it anyway”.