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Ben Affleckhas his family on his mind as he continues rehab.

On Saturday, Ben’s younger brotherCasey AfflecktoldEntertainment Tonightthat Ben, 46, has four important reasons to be sober: his children —Violet, 12,Seraphina, 9, andSamuel, 6 — and their mother, Ben’s exJennifer Garner, 46.

“Alcoholism has a huge impact on not just the person, but also their family,” Casey, 43, said toET. “I think for his kids’ sake and for their mom, and for himself, he’s trying to do the work and get it together.”

Casey noted that the Affleck family has a history of alcoholism. “Benis an addict and an alcoholic,” Casey shared at an event for his movieThe Old Man and the Gun. “Most of my grandparents are alcoholics. My father is an alcoholic, as bad as you can be, and he’s been sober for about 30 years. I’ve been sober for about six years.”

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Describing his brother’s experience, Casey toldET, “Ben is trying to put it together, and it can be a very hard thing to do. He has the kind of resources and time, luckily, to take the time and go to a good facility.”

Ben’s fame adds another level of difficulty to his struggle, Casey explained toET: “It can’t be easier to have everybody looking at you and taking your picture as you’re walking out of an intervention. I saw my father struggle with it for many years and nobody was following him around with cameras and stuff.”

He added, “It’s not a great look. But on the other hand, it’s nothing to be ashamed of and it’s good that he’s taken care of.”

Garnerdrove Ben to a treatment facility in Malibuin August andhas hosted the Affleck brothers’ mom Chrisat her home as Ben continues rehab.

A source close to thePeppermintstar recentlytold PEOPLEthat when it comesto talking to her childrenabout their father’s addiction issues, “There are no secrets, and Jen is great at explaining what’s going on in ­age-appropriate ways.”

The source added, “She tells them Ben is sick and needs doctors. What she ultimately cares about is his sobriety and whether she can rely on him to co-parent.”

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PEOPLE confirmed Ben entered rehab for alcohol addiction on Aug. 22. “He knew he needed help and was vocal about it,” a source said at the time.

“He looks much better and seems healthier,” an insider previously told PEOPLE.

If you or someone you know is in need of help, please contact theSAMHSA substance abuse helplineat 1-800-662-HELP.

source: people.com