Britney Spears just released a statement confirming the story TMZ first reported ... that she's leaving "X Factor" and will go back to making music ... but Spears notes it was a "very difficult decision."
"I had an incredible time doing the show and I love the other judges and I am so proud of my teens but it's time for me to get back in the studio," Spears said.
She continues, "Watching them all do their thing up on that stage every week made me miss performing so much! I can't wait to get back out there and do what I love most."
Spears would've made $15 million to return to the show next season ... but it's not like she'll be hurting for cash. She's currently working on her 8th album and is in serious talks to headline a show in Vegas.