Teen actress Ariana Grande suffered a crisis of confidence on the set of hit Tv show Victorious after falling out with a colleague.

The 19 year old has revealed she clashed with a co-worker during her time on the Nickelodeon series, and it made her miserable.

Grande, who doesn't name the colleague, tells America's Seventeen magazine, "I worked with someone who told me they'd never like me. But for some reason, I just felt like I needed her approval. So I started changing myself to please her. It made me stop being social and friendly. I was so unhappy."

The actress played Cat Valentine on the show for four seasons before it came to an end earlier this year (13) and she now appears in spin-off show Sam & Cat.