Dengler, aka Carlos D, parted ways with the band shortly before the release of its self-titled fourth album in 2010, and has since been pursuing a career as an actor.
And he admits he reached his decision while watching a "boring" Coldplay concert.
"I was experiencing so much pain being in the band, being in the music industry," he tells Talk Music Talk. "I have to admit that I couldn't help but feel that the band was constraining a creative impulse. It wasn't for lack of actually trying to make it work; it was still three tortuous years of trying to...
"I got sober and I said, 'OK, enough of this f**king rock star s**t. Who am I really?'"