Emma Watson constantly feels ''inadequate'' as an actress.

The 23-year-old actress lacks confidence when it comes to her abilities and always worries about being labelled a ''fraud'', despite finding success as Hermione Granger in the 'Harry Potter' franchise and then acclaim for other roles, most recently 'The Bling Ring'.

She told Rookie magazine: ''It's called the impostor syndrome. It's almost like the better I do, the more my feeling of inadequacy actually increases, because I'm just going, 'Any moment, someone's going to find out I'm a total fraud, and that I don't deserve any of what I've achieved.'

''I can't possibly live up to what everyone thinks I am and what everyone's expectations of me are.''

Emma credits 'The Perks of Being a Wallflower' director Stephen Chbosky for giving her confidence by casting her in the coming-of-age movie and helping her shake off the good girl stereotype she gained playing Hermione from the tender age of nine.

She added: ''After 'Harry Potter' I didn't feel very confident in myself as an actor. It's lucky that I've improved that now, but back then I needed someone to believe in me, and Stephen really did.''

Emma - who studied English literature at Brown University in Rhode Island, Massachusetts, but is yet to complete her studies - has ambitions to write a book but she thinks she would have to use a pen name so people could approach it without any prejudices.

She said: ''I almost feel like I would have to publish it under another name - just because there's a definition of me out there that feels kind of stuck in the moment when it was formed. I was 15 or 16 then, and I'm now 23.

''I'm not complaining, because people really have given me permission to evolve and have been very supportive of my work outside of 'Harry Potter'. So I don't feel too suffocated in that sense. But sometimes I've felt a little constrained by that idea of who I'm meant to be.''