"Ben seems to be taking it very seriously," a source told E! News. "This isn't like the other rehabs he has done in the past. This is a residential program, and he is staying on property. He is not at the point where he has a lot of freedom or is able to leave. He is doing intense counseling and spending a lot of time in meetings and therapy. He also has time in his day to workout and spend time outside in the mountains."
The source added, "He is trying to get better and really wants to for his kids."
A second source told E! the actor plans to stay in treatment until he gets it right.
"Ben is there for as long as he needs to be. Like before, he is dedicated to beating this," that source said, "and however long they feel he should be in, that is the time limit."
Ben, the second source said, is "working hard doing therapy [and] meetings" and "working out quite a bit." He's also been getting a lot of support from both Jen and his brother, Casey Affleck.
A third source claimed Ben was open to this new treatment program because he "wants to try something different and knows he needs more help."
A few days before the intervention, paparazzi photos showed Ben getting a delivery of alcohol to his house. According to TMZ, that's when Jen decided to intervene.
Since checking into rehab, Jen has been "supportive, but firm" with her ex, a fourth source told E!, adding, "She wants him to be clean and healthy and will help him get there if he's committed. She is glad he is in a safe place and getting the help he needs."