United Kingdom, April 18 -- Keri Hilson was "depressed" at the height of her fame.

The 42-year-old singer burst onto the music scene in the late 2000s with hits like 'Knock You Down', but her second album 'No Boys Allowed' in 2010 turned out to be her last record for 15 years as she tried to deal with the "beast" of being well-known.

She told People: "I didn't even know [it would be my last for so long].

"I was also depressed at the new height of my career with the success of 'Pretty Girl Rock.' I was just not okay. I was not well, I needed a break. I hadn't taken a break since I was 14 years old in my first girl group. When we disbanded, I went headfirst into songwriting at 17, got my first big check by 18. I joined another group and ...