Katy Perry's last album release 'Witness' generated extra headlines for all the wrong reasons after her former arch-nemesis Taylor Swift decided to reinstate her back catalogue on Spotify on the same day that it was released.

Swift's cheeky move raised a lot of eyebrows and kept neutral audiences entertained, but now Perry has revealed that she suffered 'bouts of situational depression' after the reaction to the album didn't pan out as she'd hoped.

In an interview with Vogue Australia, Perry said: "I have had bouts of situational depression and my heart was broken last year because, unknowingly, I put so much validity in the reaction of the public, and the public didn’t react in the way I had expected to … which broke my heart.”

She added that it had been a learning experience, however, and that she had spent a week in the Hoffman Insitute, a 'personal growth retreat', to "reboot" herself after a tough period. "Music is my first love and I think it was the universe saying: ‘Okay, you speak all of this language about self-love and authenticity, but we are going to put you through another test and take away any kind of validating “blankie”," she said. "Then we’ll see how much you do truly love yourself.’That brokenness, plus me opening up to a greater, higher power and reconnecting with divinity, gave me a wholeness I never had. It gave me a new foundation. It’s not just a material foundation: it’s a soul foundation.”

It's not yet clear whether Perry's olive branch to Swift - when she sent her a literal olive branch at the beginning of her 'Reputation' stadium tour - has seen the two former friends fully reconcile.