The 40-year-old producer has collaborated with the 'Love Yourself' hitmaker a number of times and knew he didn't need to listen to the grim predictions as their music would speak for itself.
He said: "At one point Justin was one of the most unpopular artists. But we thought, the music's going to cut through all of this, if we make something crazy and loud. And that's what we did."
The 'Where Are Ü Now' hitmaker has also worked with Madonna and admitted the 60-year-old pop legend wouldn't let him give their sessions anything but his full attention.
He told ES magazine: "Even on the first day she was not having my bulls***, I could not be on my phone -- with Madonna, it's serious work."
Diplo admitted sometimes his "emotion takes over", though he can largely keep feelings of depression at bay with his worl.
He said: "Anyone who's creative, who really is in touch with their creative side, is always going to be in touch with depression. Mostly I'm making music and I'm thinking about business, and that drowns out the emotion. But sometimes... The emotion takes over. And I have to deal with that just like anyone else. When I was younger I was diagnosed with ADHD. It's not a severe case, but I probably had other things [too].
"The really good feelings? You've got to suppress them sometimes. The high you get, it's just like taking ecstasy. The next day is the worst.
"You have to always balance that: suppress the great feelings because it will make the lows not have such an aggressive touch on your life. That's not good advice for everybody, and I know enough adult people, friends of mine, who've been suicidal and have committed suicide. I see that it's so common."
The full interview appears in this week's issue of ES Magazine, which is out now.