Ben Affleck - who has previously been in a clinic in 2001 and December 2017 - reportedly agreed to enter a facility to get help with alcohol addiction following an intervention by estranged wife Jennifer Garner.
The 'Justice League' star - who has children Violet, 12, Seraphina, nine, and six-year-old Samuel with Jennifer - was accepting of the accusations against him and was aware he needed help.
A source told 'Entertainment Tonight': "Jen is proud of the strides he's made, but some of his friends were worried he might be taking some steps backward and could be on a slippery slope.
"Ben wants nothing more than to get sober for his kids, for Jen and also for his career. He realises the dangers of what he could lose in life if he doesn't stick to the programme, and dedicate himself to these big changes."
The 'Alias' actress was seen looking "tearful and shaking" as she visited Ben, 46, at his Pacific Palisades home on Wednesday, August 22, afternoon, and shortly afterwards she drove him to a live-in facility in Malibu.
According to reports, Jennifer decided to take action two days ago after a dishevelled-looking Ben was pictured taking a delivery of alcohol a few days ago.
The 'Argo' filmmaker also called concern after he was seen partying with Playboy model Shauna Sexton following his split from girlfriend Lindsay Shookus.
The source added: "Sadly, he seemed to be putting himself in some unhealthy situations for someone who has plans to sustain a sober
"Ben was back to staying out late and hanging with his old crowd.
"Just the other night he was out late with a group of old friends and lots of women, all who were partying up a storm. It's truly worrisome for those who have seen him fall off the wagon in the past. The bottom line is he was going out again and hanging with drinkers, and it seems to have all happened too quickly.
"Lindsay was a huge support to Ben and he was doing really well. She truly helped him with his sobriety and Jen loved that he had a steady situation.
"Lindsay thought they had a future together, and she was a positive influence on him, but he felt tied down."