The trouble with these “Is this really happening, or is it all his her/his head?” thrillers is tactile.

As in, “Dude, reach out and TOUCH someone!”

Topher Grace stars in “Delirium,” the latest in a long line of horror tales where the hero (or heroine) shouting “You’re not real! This isn’t happening!”

As Tom Walker, freshly out of prison, cleared by his shrink to return to the family mansion whose last resident — his politician dad just committed suicide — has an ankle monitor, a house arrest phone line and a blunt, tactless parole officer (Patricia Clarkson).

She walks him through the house and cruelly answers his question about what happened to his father’s fanatical guard dog.

“Never get between a dog and his dinner. Your father proved that one.”

Paints a picture, doesn’t it? She’s being mean for a reason.

“After what you and your brother did, there’s nothing I’d like more than making sure you never get to swim in that pool again.”

The other thing Tom has in ready supply is medication. It’s barely able to keep the demons at bay, such as seeing that guard dog — or its ghost– chewing his dead father’s face off, or seeing that faceless father (or his ghost) wandering the halls.

He can almost shrug those off, as his shrink counseled him to “Trust my brain, NOT my eyes.” It’s “Risky Business” time in a house with all his old Presidents of the United States of America CDs, his old Gin Blossoms T-shirt, and that pool that opens up beneath a ballroom floor.

“Risky Business” mode is how Lynn the local delivery lady, played by Genesis Rodriguez, finds him. She’s all pretty-and-pushy, dolled up in Goth clubwear, and she’s curious.

“You might as well spill, because whatever you don’t tell me, Wikipedia will.”

“What’s a Wikipedia?”

Tom’s crimes will become clear, even if his mental state is meant to be entirely up in the air. Get him off his meds (parole officer’s will do that, just to mess with you) and all bets are off. Static-filled phone calls “from beyond,” creaking floors, moaning pipes.

Guzzling Nyquil isn’t enough when his partner-in-crime brother (Callan Mulvey) shows up. Or “appears.”

It’s an exceptionally good looking movie. But the performances have that hand-tied-behind-the-back quality that tales that operate by supernatural “rules” often exist under. Grace doesn’t get worked up, nor does anyone else, though Clarkson takes another run at “nasty” (check her out in “Sharp Objects”) and Mulvey is monstrous in that psychopathic way.

Tom’s reluctance to reach out and confirm or heighten his hallucination with a little physical reality, touching, is more obvious in this movie than in most of this genre.

More amusing is the “relationship” he begins with the bored, edgy Lynn, drawing her obsessively, frantically trying to chase her away each time she arrives with a delivery and a desire to chat or touch or something else.

“You’re weird and interesting…I always wanted a stalker.”

Tom’s visions grow weirder and weirder, and “evidence” — on videotapes, computer files — seems to explain some of what he’s seeing. I love it when the supernatural has a “rational” explanation.

Swimming and the pool top closes over him, the face of a woman drowned there — perhaps by his father, maybe by brother Alex.

Telling the cop about it is no help.

“You’re a nutbag,” “Trust me. The only person haunting this place is you.”

Of course she’s wrong. Or maybe she’s right. If only he had some way of FINDING out if “This is real” or “This is all inside my head.”

If only he’d stick his hand out and touch this vision or that apparition.Not that any of them are particularly frightening. Violence takes the place of terror and suspense, mystery and shock.

If only “Delirium” had been scarier.

MPAA Rating: R for some violence and disturbing images

Cast: Topher Grace, Patricia Clarkson, Genesis Rodriguez, Callan Mulvey

Credits:Directed by Dennis Iliadis, script by Adam Alleca. A Universal/BH Tilt release.

Running time: 1:36