Gwen Stefani was "inspired" by Blake Shelton

She told Glamour magazine: "It's about saving my life. And it was interesting, because I know you're going to ask me about Blake, but finding somebody who was going through the exact same experience? That was an inspiration.

"He was a friend to me when I needed a friend. An unexpected gift. And that became an inspiration in the songwriting ... It's definitely two different cultures. But there are many similarities, in things that we love and our morals. But it's really fun when you can learn about so many new things and share those differences."

Meanwhile, the 47-year-old singer previously admitted she lost her confidence as a songwriter before she started work on her new album.

She shared: "At the time, not only did my family fall apart but my kids were taken away half the time. That was devastating. But if I didn't have that time, I wouldn't have written the record. I wouldn't have healed. I had already lost so much of my confidence, even before all the tragedy. You don't understand how far gone I was.

"There was a time when I was desperate to write. You have a long career and you don't want it to end. You start to become competitive with what you've done before and competitive with things people have done after you, that are like you. So many times I've gone into the studio and people are excited about me being there, yet don't have the confidence I can do anything any more. I had been praying I would find something. For this album I had the right team. When I wrote 'Used to Love You', that was a huge turning point."