Negative comments from trolls convinced Hailey Bieber her marriage to singer Justin wouldn't last.

The couple married in an intimate ceremony late last year (18) and will stage a second celebration for family and friends on 30 September. And while their relationship has gone from strength to strength, the model told Vogue Australia speculation about her marriage had a negative effect on her mental health.

"What’s so tricky about mental health is that it can be easy to let people convince you of something that’s not real…," Hailey, 22, shared. "When I had hundreds of thousands of comments bombarding me with: ‘He’s never going to this’, ‘You’re never going to that’, ‘You’ll be divorced by then’, you can’t help but wonder: ‘Does someone see something that I don’t see?’

"It starts to mess with your mind," she added.

But the star insisted she's now adopted a different mindset and is working to make her relationship more private to help keep the speculation at bay.

"The only two people in a relationship are the two people in it. I’ve been working on retraining my thought process to understand that," the star explained. “Nobody from the outside really knows what’s going on between us. I wake up every morning with this person. I’m the only person that has direct dialogue with this person. This is my relationship."

Justin, 25, also recently opened up about their marriage, in a candid note on social media, gushing over Hailey, and admitting she has taught him how to be "a good man".