Dakota Fanning thinks 'The Bell Jar' is an ''important story'' to tell.

The 24-year-old actress will portray Esther Greenwood and her battle with depression in Kirsten Dunst's upcoming adaptation of Sylvia Plath's classic novel and she thinks the movie will surprise a lot of people.

She said: ''It's such an important story, and really different from what people think it is.

''People think it's depressing, or a biography of Sylvia Plath, but it's not and there's so much humour in it. You follow a young woman during a formative time in her life, and see how overwhelming the expectations of what women feel they are supposed to be like can be. We all feel that to some extent.''

And Dakota admitted she is looking for similar roles in the future.

She said: ''I like playing characters where everyone thinks they're one thing but they know they're not.

''That interests me, because I feel like, in my life, I'm trying to work that out.''

The 'Alienist' star's younger sister, Elle Fanning, 21, is also an actress and though they are occasionally up for the same roles, the siblings are not competitive because they are very different.

Dakota explained to Sunday Times Style magazine: ''We're apples and oranges. We've definitely had meetings for the same thing in the past, but it's not weird because we feel so different from one another that it's, like, 'If you want me, then she might not be right.'

''Elle wears her heart on her sleeve, she's the typical younger one, very free-spirited and can't be tamed, while I've always been quieter and more of an observer, and I keep everything to myself until I feel comfortable. She's wild from the start, and her laugh is really loud and specific. You don't hear me coming until you do.''