"Scott is really trying to work on himself," the Keeping up with the Kardashians matriarch, 54, told PEOPLE at the show's season 5 press gathering. "Scott has really stepped up to the plate. It's been amazing, because Kourtney and him are really trying to work on their relationship."
According to a rep for the show, Kardashian and Disick are in couples therapy, and Disick has been abstaining from drinking.
Jenner says even though not every moment filming with Disick has been pleasant, his presence on the series has been helpful – to him.
"The show's been instrumental in helping Scott see a very dark side of himself," Jenner explains. "When you see your behavior on a television screen in color, you might wake up one day and say, 'Gee, I might have a problem.' "
Jenner's other daughter, Kim Kardashian, says she's "always been supportive of Scott and Kourtney's relationship," adding that her mother has been "more sympathetic" to Disick's problems since he has made an effort to seek help.
"I was always more like, 'Scott, get it together,' " Jenner says. "And when he didn't, I got angry, because I didn't understand that he had a disease."
Meanwhile, in other Kardashian relationship news, despite being seen all over town with Dallas Cowboy Miles Austin (and sharing lip-locks with him in the KUWTK season 5 trailer), Kim insists she's totally unattached, and Austin won't be featured regularly on the show.
"[Having Miles in the season trailer] was a great teaser," Kim says. "This season is all about me being single. This is the one time in my life where I can be 100 percent selfish. I don't have a husband, I don't have babies. I don't really have any other responsibility. I can focus on work and me. That's really what I want to do. So, I don't think you'll see too much of any [guy] on the show."
The new season of Keeping Up with the Kardashians premieres Sunday, August 22 on E!.