Sia said Katy Perry working on her mental health was "the best thing that could have ever happened to her"

Sia is sharing how she bonded with Katy Perry over their mental health struggles.

In a new interview with The Los Angeles Times, the "Chandelier" singer, 44, opened up about meeting Perry in 2014, becoming fast friends as Perry acted as Sia's "pop-star concierge" during her rise to mainstream stardom.

Their friendship became more than just surface-level after they opened up to each other about their individual internal strifes.

"She had a real breakdown," Sia said of Perry, 35. "She’s on stage with 10 candied lollipops and clowns and dancers, selling the dream, the joy, the happiness — and that’s really hard sometimes when you’re not feeling it yourself."

"I knew she was driven and ambitious, that was clear from the beginning. But I didn’t realize that she was so reliant on that validation for her psychological well-being," she continued. "She did say ‘I feel lost.’ I think it was a big kick to her ego, but it was the best thing that could have ever happened to her, really, because now she can make music for the fun of it. Getting No. 1's does nothing for your inside.”

Sia also shared that she was close with both Perry and Orlando Bloom, who are now engaged and expecting a daughter together. "I’d be on the phone with Orlando and have call waiting with Katy trying to call me," she recalled.

Sia and Katy Perry
Sia and Katy Perry
| Credit: Todd Williamson/January Images/Shutterstock; Adam Bettcher/Getty

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Earlier this month, Perry opened up to PEOPLE about overcoming her "darkest" days. After surviving those difficult years of her life, the "Smile" singer said she's now well-equipped to handle some curveballs.

"Having a great partner, having a sound mind, continuing to do the work, I'm not as flinchable," said the star, who found relief from a deep depression over the last several years with a combination of medication, therapy and support from loved ones. "I'm not untouchable or invincible, but it's a little bit more like water off a duck's back."

Perry also reflected on how far she's come since 2017 when her album Witness failed to make the same impact as her previous record-breaking hits. Around the same time, she also put her then-yearlong romance with Bloom on hold.

Katy Perry
Katy Perry shot at Lotusland in Montecito, California

"After being on a rocket ship and just going straight up, it was just a small change in the trajectory, but it felt seismic," recalled Perry. "It's been two-and-a-half years of trying to find my footing. It's so easy for me to work, work, work and avoid, but I had to go on a mental and spiritual journey."

RELATED VIDEO: Katy Perry on the Resilience She Found After Surviving Her ‘Darkest’ Days: ‘It Was All Worth It’

The artist told PEOPLE that her lowest points felt like a "nightmare," saying, "You feel like you're being attacked, and you can't wake up."

"We all have negative conversations going on in your head that can take the wheel. You have to take the wheel back, and I definitely did," she said. And though the process was at times unbearable, Perry shared that the devastation she felt was necessary for her to finally shift priorities.

"It got me out of this desperate loop of being the 'best pop star ever.' I just really want to be a human being and have the dimension of life," she said. "... [Now] I get to live life, and I get to bring life into the world. Finding the gratitude in this pain has been a real journey, but the outcome is worth it."

If you or someone you know need mental health help, text "STRENGTH" to the Crisis Text Line at 741-741 to be connected to a certified crisis counselor.