Nina Dobrev, who played the role of Elena Gilbert on The CW's "The Vampire Diaries," left the show in 2015 after six seasons. Now, the 28-year-old Bulgarian-Canadian actress has explained why she chose to depart.

In the September issue of Harper by Harper's Bazaar, Dobrev said her exit from the supernatural drama series was her plan from the beginning. Before the series aired, she already knew she wanted her character's story to be a six-season adventure.

"The fact that [leaving] terrified me drove me even more," she continued. "I needed to feel that fear of 'Oh, my God, what if I never get a job again?' That just made me want to work five times as hard to make sure that didn't happen."

While she is flattered when people applaud her performance in "The Vampire Diaries," Dobrev admitted she wants to take a break from teen dramas. Instead, she wants to play more mature roles in future projects.

"The things I want to do aren't necessarily the things that are expected of me," she continued. "I want to play adult roles and be challenged and work with great filmmakers and tell incredible stories, and that has meant being really picky."

Dobrev can be seen next in "Flatliners," an upcoming psychological horror film directed by Niels Arden Oplev ("The Girl with the Dragon Tattoo"). In the film, she will play an overachiever medical student named Marlo.

"Flatliners" is a sequel to the hit 1990 film of the same name and follows medical students Marlo, Courtney Holmes (Ellen Page), Ray (Diego Luna) and Jamie (James Norton) as they try to find out the truth about the afterlife. Hence, they conduct surreptitious experiments on each other that will produce near-death experiences.

Also starring Kiersey Clemons, Kiefer Sutherland, Beau Mirchoff and Charlotte McKinney, "Flatliners" is set to be released by Columbia Pictures on Sept. 29.