Halsey was "terrified" when she became ill shortly after becoming a mother

She told The Hollywood Reporter: "I was in that in-between space, waiting for answers from doctors for months of like, you know, not only could I be not in a position where I get to be a musician anymore, but I don't even know now if I'm going to get to be anymore. And that was terrifying.

"Kind of like the greatest thing in the world ever happened to me [becoming a mom]. And then all of a sudden, a really scary thing happened to me.

"And then I knew that I had to start writing because I knew that that was going to help me process what was going on."

Meanwhile, Halsey - whose real name is Ashley Nicolette Frangipane - caused a stir when she sampled the classic Britney Spears track 'Lucky' in her song of the same name and insisted that she did get permission from the pop superstar to do so.

She said: "She was so supportive out the gate. I thought it was gonna take some convincing because I didn't think she knew who I was.

"I didn't just reach out to her cold, because, what do you do? You don't just reach out to Britney Spears. I wrote this really long letter... just talking about her and how much I love her in the song. And you know, what I'd been going through and what it meant to me. And I'd also just become a single mom, you know? So I really related to her in that way as well."