We don’t mislabel it “schizophrenia” any more. And few call them “multiple personalities” these days. It’s “Dissociative identity disorder” now.

But it’s still every actor’s wet dream. And given the chance to play a kidnapper with an array of guises living in his darkly disturbed skull, James McAvoy does what any gifted actor would under the circumstances.

He chews up the screen, the supporting cast and the movie, and then dabs his lips with his napkin, ever-so-demurely.

In “Split,” he plays a creep who kidnaps and imprisons three tartly-dressed teens —  Anya Taylor-Joy, Haley Lu Richardson, Jessica Sula. They’re freaked out enough, packed into a makeshift dungeon with no TV, no cell reception and nothing to occupy their short attention spans but their doom.

And every time their keeper unlocks the door, he’s “different.”

There’s Dennis, who buttons his shirt all the way to the top like all movie rapists and serial killers. When he barks “I choose YOU first,” the girls assume the worst. Intrepid Claire (Richardson) shrieks, frozen-in-fear Marcia (Sula) weeps in shock.

Only the odd-girl-out, a pity invite to Claire’s mall birthday party, shakes off the shock long enough to react to an impending rape.

“PEE on yourself,” she hisses to Marcia. It works.

Casey (Taylor-Joy of “The Witch”) has inner resources and a dark past. We start to learn about this in flashbacks.

Dennis, the trio discovers, isn’t alone. Shaved head in earrings and high heels, he returns as the ever-so-proper Patricia, or the nerdy nine-year-old Hedwig.

Hedwig?

Claire is all about forming a plan and ganging up on this short but muscular creep. Casey, as shaken as any of them, isn’t ready.

“I’ll let you know when I hear something that makes sense.”

It turns out, “Kevin” is under a doctor’s care. Betty Buckley plays a psychotherapist specializing in D.I.D. patients, and she thinks she’s made a breakthrough, a discovery that will alter our way of looking at such people and at reality. Pity she can’t connect “Barry,” the fey would-be costume designer, Patricia, Hedwig, Dennis or the others living in Kevin’s head with news reports that three girls were just kidnapped, in broad daylight, at a suburban Philly mall.

Writer-director M. Night Shyamalan weaves together three points of view and three storylines — the trapped girls, Casey’s past and Dr. Fletcher’s sympathetic, earnest and probing “treatment” of Kevin — in crafting this standard-issue psycho-abduction thriller.

Shyamalan gets his chutzpah, if not exactly his mojo back with this solid and modestly thrilling thriller. While it is markedly inferior to such recent hostage pictures as the riveting and Oscar-winning “Room” and the tighter, tense “10 Cloverfield Lane,” Shyamalan feels comfortable enough to go back to his old tricks after years in the director-for-hire (“The Last Airbender,””AfterEarth”) and cheap, gimmicky horror (“The Visit”) wilderness.

He builds gravitas into the story with madcap theories about the explainable supernatural, packaged in the person of Buckley’s “I’m onto something BIG” shrink.

He ties the picture into his early career continuum, linking it to the storylines he cooked up back when he was a Time Magazine coverboy/wunderkind.

And Shyamalan gives himself a cameo, with speaking lines, always a mistake. He’s not so much a bad actor as a distractingly dull one.

The young actresses are given roles with traces of pluck and self-reliance. But they’re objectified, presented in various stages of undress, a heavy-handed tease that a sex crime might be in their future.

That gives the film a standard horror movie failing — a disconnect, an empathy gap. The suspense doesn’t build as they race towards their fate. There is no pulse-pounding feeling to any “They/she might get away” moment. Casey may have demons to exorcise. We’ve seen the “Signs.”

But Shyamalan treats her, like everybody else, as an exotic lab exhibit he and we study, not people root for.

That leaves us with McAvoy, finally ripped out of that “X-Men” wheelchair and given his juiciest, most over-the-top part since “Filth.” He minces, he broods. He tries to manage walking on high heels. He’s fun to watch, but it’s a showy, obvious and flamboyant performance.

There’s just enough connection to the current psychological theory to give “Split” resonance, but too many Shyamalan indulgences and nods to his past to let it stand on its own. And when in the third act he brings it all together and tries to sprint for the finish, all he can manage is to ego trip over his past.

MPAA Rating:PG-13 for disturbing thematic content and behavior, violence and some language

Cast: James McAvoy, Betty Buckley, Anya Taylor-Joy, Haley Lu Richardson, Jessica Sula

Credits:Written and directed by M. Night Shyamalan. A Universal release.

Running time: 1:57