Two years later, the band returned to the charts with "Everybody Talks,"off 2012′s Picture Show. It, too, did well on the charts (No. 6 on the Hot 100), and earned more Glee love. They did another commercial, this time for Buick Verano, which not only featured "Everybody Talks" but the band itself.

It was all very exciting for the Provo, Utah band, but success started to take a toll on Glenn. "I always felt like we were playing catch-up," the singer told Radio.com. "And I always felt mentally, even like physically, I was figuring out who I was on stage� and that was a weird sort of thing for me to struggle with while gaining more popularity."

At some point, Glenn says, he started having an unhealthy outlook on life and told his bandmates-guitarist Christopher Allen, bassist Branden Campbell and drummer Elaine Bradley-that he wanted a break. The foursome canceled their tour and Glenn started seeing a therapist who helped him feel happy again. "It took a little while," Glenn admits. "And there's a lot of things I'm still working on."

The band's upcoming record, Pop Psychology (out April 22), is the result of Glenn's therapy sessions. "At moments there's a cry for help and sadness," he said of his band's third album. "But I think it's a real fun pop record at the heart of it and something with a message too."

Glenn admitted that he has always been a "strangely honest" person who often shares too much with his friends and family. So when it came to writing this album, he never felt like he had to hide the demons he was facing. If anything, he felt it would be a disservice to keep his mental issues a secret.

"There are some people that really come to our shows kind of clinging on to something, and I didn't want to stand up in the front of the stage and say, 'Be yourself and be happy with who you are' if I wasn't," Glenn explained. "I felt like it was lie."