MUMBAI: Paris Hilton is continuing to open up to her fans.

The 39-year-old heiress is dropping a new documentary called This Is Paris this September. The Simple Life star gave her followers a peek at the film on Tuesday's episode of Jimmy Kimmel Live!.

"No one really knows who I am," Hilton said in the preview. "Something happened in my childhood that I've never talked about with anyone. I still have nightmares about it."

While Hilton didn't go into detail about her experience in the clip, People, which also obtained a preview of project, reported the video shows Hilton preparing to discuss the mental abuse she faced as a teenager at a Utah boarding school.

During her interview with Nikki Glaser, who filled in as guest host amid Jimmy Kimmel's summer break, Hilton reflected on how she's feeling about the documentary's upcoming release.

"I'm excited, but I'm also very nervous, you know, given the topics discussed in this film because it's things I've never talked about before—really personal and traumatic experiences," she said. "So, to talk about that publicly is obviously very hard."

She also talked about the filming process and how she was able to show a different side of herself.

"Obviously, I'm used to being on camera from being on camera for so long," The Simple Life alumna said. "But I've always been a very naturally shy person. So, I loved just inventing this character and playing that character. And to actually be myself was a completely different experience, but also almost therapeutic in some way where I learned so much about myself that I had no idea of why I am the way I am and now I understand myself so much more."