In the show, which airs on MTV Sunday at 10 p.m. ET, Britney questions her behavior over the last couple years and sheds some light onto what it's like to be her on a daily basis. "I've been through a lot, and there's a lot people don't know," she says.
"I don't think anyone can prepare themselves for what stardom brings. ... It didn't touch home with me, the whole fame thing, until I had a huge breakup, and I wanted to just ... stop," she continues. Sometimes it can get lonely, because you don't open the gate up that much. ... So I'm kind of stuck in this place, and it's just, 'How do you deal?' I just cope, and that's what I do, every day."
In the documentary — which premieres two days before the December 2 release of her new LP, Circus, — fans can get a glimpse of Spears' life as she prepares for the album's release, which includes photo shoots, dance rehearsals and time with her two sons, Jayden James and Sean Preston.
"There's a lot people don't know about me that I want them to know," she said. "I've been through a lot the last two or three years. I've grown up, bigtime."
However, not all Spears' revelations are about her very public personal life over the last few years: She also talks about still loving her career, even after more than a decade in the business. "I recorded the album. I recorded a lot of songs and it's the process where the fun stuff starts to come," she said of Circus.
Spears also talks a bit about life under her conservatorship, which includes supervision by her dad Jamie Spears over her affairs. "I think it's too in control. If I wasn't under the restraints I'm under, I'd feel so liberated," she said. "When I tell them the way I feel, it's like they hear, but they're really not listening."
She added, "I never wanted to become one of those prisoner people. You're guarded. You have to be that way."
Britney's manager, Larry Rudolph, discussed the documentary at a screening in Los Angeles on Friday. "You see Britney in a light you're not used to seeing her in," he said. "She's intelligent, she's introspective, she's honest. By the end of the film you really understand who she is in a way that you just never imagined. ... It is so not a puff piece."
Getting pumped about the Britney Spears documentary? Share your thoughts by uploading a video to YouRHere.MTV.com, or sound off in the comments section below. "For the Record" airs Sunday at 10 p.m. ET on MTV.