Halsey thought she would "die" if she wrote an album of "angry" songs.
The 25-year-old singer initially penned ‘Nightmare’ for her new record ‘Manic’ but decided not to include the dark track on the LP and wouldn’t give into calls from fans asking for similar-themed songs because she felt having to perform them would be detrimental to her mental health.
Halsey – who has been open about her struggles with bipolar disorder – said: "I was like, ‘Woah. I can’t make an album full of songs like this, I will f***ing die. I can’t be out being angry all the time, it’s going to hurt me.’
"My fans keep saying, ‘We want more angry songs like ‘Nightmare’.’
"I’m like, ‘You don’t understand what that would do to my mental health.’ If I have to go on stage and be angry all night, every night, then that has an effect on me. I couldn’t do that."
And in addition, Halsey didn’t think she could write any similar songs because she’d vented all her frustrations in ‘Nightmare’.
She added in an interview with The Sun newspaper: "At the same time, I couldn’t think of anything to say because I wasn’t mad any more.
"That was a lot I had to vent with ‘Nightmare’, and I did it and then I had nothing else to do to draw from. Once I made peace, I was done with the anger."
Despite having collaborated with the likes of Post Malone and Justin Bieber in the past, the ‘Clementine’ singer found it "terrifying" approaching Alanis Morissette for ‘Mania’ track ‘Alanis Interlude’.
She explained: "It was so scary because I thought she was going to say no. And then she said yes, which is even crazier. She hasn’t put out music in 13 years.
"My mum raised me on her music. It was so important for me to have her on a record that is so about me and the development of me.
"Then working with Suga from BTS on ‘Suga’s Interlude’ was awesome because he is by far the quietest member of the group and his lyrical content is so introspective. And I also work with Dominic Fike on ‘Dominic’s Interlude’. He is brilliant and is going to have a massive career."