The title makes it sound like a sixties slasher movie, but “Hysteria” is a genteel, genial British period comedy with just enough naughtiness to make the older women who are its natural audience blush happily. Unfortunately, while it has some amusing moments, the picture never really takes off.

The script by Stephen and Jonah Lisa Dyer is based on the fact that electric vibrators became a popular mode of medical treatment for women suffering from mental distress in Victorian England. It assigns the invention to Mortimer Granville (Hugh Dancy), an idealistic young doctor who, ostracized by his more hidebound colleagues, joins the practice of Dr. Dalrymple (Jonathan Price), who specializes in the women’s trouble generally called hysteria, a diagnosis that covers virtually any sort of emotional upset. Ascribing their problem to an overactive uterus, Dalrymple’s treatment involves massaging a patient’s private parts manually, using an elaborate curtained contraption to provide a degree of decorum. When a woman reaches “paroxysm” and her symptoms abate, albeit temporarily, a cure has been effected. No wonder Dalrymple is inundated with patients and needs an assistant to meet demand.

Unfortunately, after a decent start Granville proves an unsatisfactory substitute, suffering from hand cramps that undermine the treatment. Fortunately, his layabout aristocratic friend Edmund (Rupert Everett), whose parents are Mortimer’s guardians, has an interest in electricity, and by accident Granville realizes that his latest contraption, a motorized feather-duster, might be adjusted to serve as a more reliable mechanical replacement for Dalrymple’s manual method. A test on a particularly stern patient proves a terrific success, and the market for the massager booms, leaving both Granville and Dalrymple wealthy men.

There’s also a domestic twist to the plot, since Dalrymple has two daughters with whom Granville gets involved. One is Emily (Felicity Jones), a prim, proper blonde who’s expert in phrenology and whom the young doctor romances. The other is her opposite—Charlotte (Maggie Gyllenhaal), a feisty brunette who defies social norms by fighting for women’s rights and the care of the downtrodden, embarrassing her father in the process. Mortimer is flummoxed by Charlotte’s passion, but it’s a foregone conclusion that in the end, she’s the girl for him—something made abundantly clear in a far too calculated courtroom scene in which, as an expert witness, he chooses to stand up for her progressive notions in the face of attempts to trundle her off to a mental institution.

There are episodes of “Hysteria”—pun intended—that suggest the sort of old-fashioned British nonsense it might have been. An gaffe-laced encounter between Charlotte and Granville’s guardians (Gemma Jones and Malcolm Rennie) at a soiree, for example, has a bit of the goofy humor that marked pictures like “The Wrong Box,” which also dealt comedically—among other things—with Victorian sexual repression. But for the most part the gags fail to ignite. One might imagine, for example, that the scenes of heavily corseted ladies undergoing Dalrymple’s treatment would be guaranteed howlers, but instead they’re oddly mirthless. A postscript about the queen probably sounded funnier than it turns out to be. And the entire subplot centering on Charlotte’s activism comes across as forced deference to modern feminist attitudes.

It certainly doesn’t help that Gyllenhaal overplays badly, never even trying to seem in period. (Her accent is about as good as Kevin Costner’s was in “Robin Hood.”) Dancy is a lightweight, younger Hugh Grant, which isn’t a bad thing, Pryce certainly has his moments, Jones is the very model of proper womanhood, and Everett is (as always) a smoothly accomplished scene-stealer. They’re all hobbled, though, by material that’s less than stellar. (You know you’re in trouble when early on, to establish the time when the story’s set, the writers have a character shout “This is the 1880s!” as if his listener had to be told that.)

“Hysteria” tries to be a throwback to the good old days of British comedy. But it suggests instead that those days might be gone for good.