The 31-year-old musician, who formed the band in the early 2000s with twin brother Gary and younger brother Ross, said that he received treatment after being "ill" and is now on the road to recovery.
Jarman told NME magazine: "I've been living with Ross for the last few months. We're closer than we've ever been. And Gary's been in America so I go out and see him. I felt those guys came through for me.
"I was just quite ill last year, during the writing of the record, and it's cost me a lot. I had real self-loathing issues. Things are getting better… the last couple of years haven't been easy."
Ross admitted that he wasn't sure about whether The Cribs should go on tour due to Ryan's state of mind. He said: "Going back on the road… I don't necessarily think it'd be a good thing for him, mentally. It does concern me. We're a close band, so I think it'll be okay."
Ryan also revealed that during his "ill" period, he also split from long-term girlfriend, singer Kate Nash. The couple got together in 2007.
> The Cribs unveil new single 'Come On, Be a No-One' - listen
> The Cribs confirm fifth album details, UK tour
Watch The Cribs' 'Hey Scenesters' music video below: