As “Still Alice” begins, Alice Howland appears to have it all. She’s a renowned linguistics professor at Columbia University in New York. She’s happily married to a fellow academic with whom she has three adult children.

The film adaptation of “Still Alice,” based on Lisa Genova’s 2007 novel, opens during a 50th birthday celebration for Alice, a happy occasion at a fine restaurant. Most of the family is there, with the exception of youngest daughter, Lydia, who’s pursuing an acting career in Los Angeles.

An early hint of trouble comes later. While visiting scholar Alice is delivering a guest lecture at UCLA, her mind momentarily goes blank. And then back in New York during a jog, she suddenly doesn’t know where she is.

The efficiently paced “Still Alice” wastes no scenes. After showing the audience how much Alice has to lose, the film shows her losing it.

Julianne Moore stars as Alice, a bright, accomplished woman who’s sideswiped by a diagnosis of early-onset Alzheimer’s disease. Moore’s finely honed, affecting performance makes her a frontrunner for an Oscar. She’s already won best actress honors from the Golden Globes and the British Academy Film Awards.

The movie features high drama in intimate settings. Unable to sleep one night, the upset Alice awakens her husband, John.

“It feels like my brain is dying,” she tells him. “And everything I’ve worked for my entire life is going.”

“Two things,” John replies. “It’s way too early to jump to conclusions and, whatever happens, I’m here.”

The plainspoken Dr. Benjamin (Stephen Kunken) tells Alice and her husband, played by Alec Baldwin, the facts as they reveal themselves. Alice’s sporadic memory impairment is out of proportion for someone her age, the doctor says. The simple truth, spoken without emotion, nonetheless sounds so cruel.

The writer-director team of Richard Glatzer and Wash Westmoreland detail Alice’s decline in quick, devastating steps. Like the doctor who frankly delivers his Alzheimer’s disease diagnosis, the film stays straightforward in its depiction of the progression of Alice’s disease and its effects upon her family.

Moore courageously portrays the heartbreaking transformation Alice experiences, staying perfectly in step with the aggressive toll the disease takes. As Alice endures a series of losses and humiliations, nothing is romanticized or glamorized.

But Alice is a brave woman, determined to hang on to her life as she’s known it for as long as she can. To that end, she continues to tell her daughter, Lydia, played by the post-“Twilight Saga”-Kristin Stewart, that college is a better choice than struggling to be an actress. Alice and Lydia’s difficult relationship becomes the principal relationship in the film, more important than Alice’s relationship with her husband. One-on-one scenes featuring the ailing mother and rebellious daughter are also among the film’s most revealing.

There’s also the frightening possibility that Alice’s children will inherit Alzheimer’s disease from their mother.

“What’s it like?” Lydia asks.

“On my good days I can almost pass for a normal person,” Alice replies. “But on my bad days I feel like I can’t find myself. I don’t know who I am and I don’t know what I’m going to loose next.”

As Alice loses more and more of herself, aging what appears to be a decade in months, Moore’s beautifully sad performance spells the tragedy out for all to see. It’s difficult to shake.