In the sometimes enjoyable campiness of "Running with Scissors," based on Augusten Burroughs' best-selling memoir, lurks a performance of surprising delicacy. Annette Bening, elongated in trailing '70s fashions and a limp shag haircut, plays Deirdre, a would-be poet and a mother so indifferent to her teenage son, Augusten (Joseph Cross), that she sends him to live with the eccentric family of her psychiatrist, Dr. Finch (Brian Cox). She even allows Finch to legally adopt him.

We're not meant to love Deirdre, and we don't: Bening gives her a razor-sharp snarl (criticizing another writer's work, she meows, "I was bored") and a cool breathiness in the beginning, as her marriage to Norman (Alec Baldwin) is ending. But this is a performance far more subtle than the '70s kitsch that surrounds her.

Deirdre has a faint desperateness in her eyes, and a childlike grin that soon fades. Later, as she slips further into the twilight of prescription drugs, she seems to get smaller as we watch. Her voice grows soft and slurry; her eyes seem to be seeing things that aren't there. In a beautifully filmed and performed sequence near the end, she slips off the precipice of madness, dancing joyously to an invisible orchestra.

It's a fine, accomplished performance, but it throws the movie out of whack: "Running with Scissors" is not Deirdre's story — it's her son's.

Burroughs' book gave us occasional glimpses of a mysterious, disturbed woman, but mostly focused on the first-person journey of a young man navigating a hellishly unstable adolescence. And so Cross, at the center of the film, has an almost impossible task: He needs to make us not wish to have Bening back on screen, and his sensitive but slightly bland performance can't quite do it.

Cross has some touching moments: Told of someone's dream of raising a family, he says quietly and wistfully, "That's a good dream to have." But, in playing an essentially unformed character, he can't compete with the full-on symphony of Bening.

Other actors wander in and out of the movie, mostly in quirky mode: an unrecognizable Jill Clayburgh as the doctor's faded wife, Agnes; Gwyneth Paltrow and Evan Rachel Wood as his oddball daughters.

Director Ryan Murphy (who also wrote the screenplay) veers between deadpan comedy and coming-of-age pathos, all set to an over-the-top '70s production design and score. "Running with Scissors" looks great, and works fine when Bening is on screen; otherwise, it's off-balance, teetering where it should hold steady.

Moira Macdonald: 206-464-2725 or mmacdonald@seattletimes.com