From the very first shot, “Thirteen,” a documentary-style film about a junior high school pariah-turned-bad-girl, packs a punch — literally. The first scene depicts Tracy (Evan Rachel Wood) and her drug buddy Evie (Nikki Reed), sitting on Tracy’s bed taking hits from an aerosol can and reeling from the resulting numbness they feel. They command each other to slap and punch each other in the face and then erupt in giggles when neither of them feels a thing.

The rest of the film, which recounts the four months of Tracy’s physical and emotional transformation, feels very much like a punch in the face. “Thirteen,” Catherine Hardwicke’s directorial debut, portrays Tracy, an innocent outcast with a girl-crush on Evie, the most popular girl in their Los Angeles junior high school. Evie is a nubile nymphet, who all too easily converts a tube top into a micro-mini skirt and climbs out of bedroom windows into the groping arms of awaiting boys. With her low-slung jeans and flowing hair, Evie embodies that iconic girl in junior high we all knew, and Tracy will do anything it takes to be adopted into her elite circle of friends.

When Tracy passes a modern rite of passage by stealing a woman’s purse, she proves her daring nature to Evie, and the two become fast friends and shopping (read: shoplifting) buddies.

Under Evie’s tutelage, Tracy undergoes an inevitable makeover. But don’t be mistaken — it doesn’t stop with an innocent shopping spree at Skechers. (“Thirteen” is not simply about the influences of consumer fetishism). Instead, the film follows Tracy’s downward spiral into the unfortunate triumvirate of drug abuse, depression and self-mutilation. Manipulative and motherless, and herself a victim of abuse, Evie encourages Tracy to partake in all meanings of the word.

“Thirteen” is blunt and bold and tries to tell the whole truth of being that unlucky age — gore and all. The film admirably portrays the ugly truths of teenagers, like how easily friends are dropped and how quickly one can fly through the ranks of cool. But sometimes, “Thirteen” is a little too much to bear and has the audience cringing in its seats. The film includes many close-ups of self-mutilation, including Evie piercing Tracy’s navel and Tracy slitting her own wrists (with nail scissors, no less.)

Since it is backed by a blaring soundtrack that drowns out much of the dialogue, the film is left looking like an extended rock video. And the shaky movement of the hand-held camera is often dizzying — it wouldn’t have killed them to use a tripod.

The camera, however, is not the only mobile thing in the film — the focus shifts frequently. At first, the hell that is junior high school is seen through Tracy’s eyes. We commiserate with her inability to be cool. Initially, Tracy is likeable, even endearing, in her self-conscious awkwardness. But though Tracy is initially warm and likeable, as soon as Evie convinces her to pierce her tongue, all the words that subsequently fly from her mouth are as cold as that metal stud. Tracy becomes distant and unknowable, even to her own mother.

Here, the film shifts from being a story about the friendship between two girls, to one of the crumbling relationship between a mother and daughter. Tracy’s mother, played by Holly Hunter, is initially a cartoon. She is a flighty hairdresser who struts around the house in camisoles and tight jeans and who snogs her cokehead boyfriend in plain view of her daughter. But when she finally becomes aware of her daughter’s downward spiral into self-destruction, the film’s story becomes one of rescue.

Though heavy and wrenching, “Thirteen” does have several hilarious scenes, especially one priceless moment with a chicken. And the camera does eventually slow down enough to savor the cinematography. Look for a beautifully filmed sequence in which Tracy takes her first acid trip in a park after dark and dances with her friends in the sprinklers.

Though “Thirteen” tries to be relentlessly blunt, or perhaps because of this, the film lacks the mystery and haunting quality of something like “The Virgin Suicides,” another film that deals with similar issues of depression, teenage angst and dysfunctional family relationships.

“Thirteen” is melodramatic and exploitative, but the film is also relentlessly fast and harsh. It’s also an amazing feat, considering Reed co-wrote the script when she was only fifteen years old. “Thirteen” is not so much engrossing as it is fascinating, in the way that a car accident has that can’t-look-away appeal. And so you watch, mouth slightly agape, wondering where it will end, how far will she stray and how low those jeans can possibly go.