Conceived as a bitter little pill to dull optimism and shatter serenity, Downloading Nancy was nominated for the top prize at last year’s Sundance, where voters must have been taken in by Maria Bello’s virtuoso performance and the scenes of raw emotional energy she commands. Whether those voters stopped to consider the point of such scenes, much less the point of the movie itself, is debatable.

There are moments of disturbing honesty here – consider the scene in which Nancy (Bello), self-pitying and seemingly impenetrable, goads her ineffectual therapist (Amy Brenneman) into a temper tantrum of her own – but watching Downloading Nancy is like being made to ponder a series of open wounds. It is a singularly joyless experience, unrelenting and melodramatic to the point of self-parody, and if you find yourself tiring of Nancy’s clichéd outbursts (“You don’t know what real pain is!”), you’re not alone.

Nancy wants to die. Saddled with a distant husband (Rufus Sewell, of Dark City) and a history of abuse, self-inflicted and otherwise, she obsessively cuts herself and searches for someone willing to finish the job. Louis (Jason Patric, humorless in a role that demands it), a fellow pain addict she meets on the Internet, wants to help her, though it’s hard to fathom why. While he shares Nancy’s taste for torture, Louis seems disinclined to take a life. He is intrigued by the fantasy but repulsed by the reality.

Downloading Nancy works best when the stakes are highest and the outcome most in question, as when Louis confronts the golf-obsessed Albert (Sewell) about his wife’s disappearance. For a fleeting moment, the picture comes alive with an almost palpable tension – violence seems in the offing, but how far will Albert, an emotional shell of a character, go to protect his loveless marriage?

Elsewhere, the story, written by newcomers Pamela Cuming and Lee Ross, unfolds in predictably hysterical fashion. Bello throws herself into Nancy admirably – she’s all nerves and anguished sobs, but grounded enough to seem human, rather than a depressive stereotype. Yet Downloading Nancy squanders her talents, and what’s left of our patience, en route to a finale that is neither surprising nor illuminating: Like the rest of the movie, it’s misery for misery’s sake. Consider yourself warned.