RYAN SEACREST and JULIANNE HOUGH have broken up.  The split was amicable . . . she just got tired of his work schedule . . . which is pretty relentless.

--A source says, quote, "He works all the time.  He never sleeps.  It's a lifestyle she couldn't handle anymore.  Work always, always came first.  She wants a more low-key life."  (--Ryan is 38, Julianne is 24.)

--On Saturday, Julianne Tweeted a picture of herself with some friends, along with the hashtag "friends are the best therapy".  (--One of those friends is Nina Dobrev from "The Vampire Diaries".  She's the one on top.  Here's the pic.)  (Instagram)