Ben Affleck opens up about the 'lifelong and difficult struggle' of alcohol addiction "I am fighting for myself and my family," he wrote.

Ben Affleck opened up this week about his “lifelong and difficult struggle” with alcohol addiction.

The Oscar winner said in an Instagram post on Thursday that he has completed a 40-day stay at a substance abuse treatment center, and remains in outpatient care.

Battling addiction, he added, "is a full-time commitment," noting that "one is never really in or out of treatment."

"I am fighting for myself and my family," he continued, thanking those who have shared their personal stories of addiction with him. "With acceptance and humility, I continue to avail myself with the help of so many people and I am grateful to all of those who are there for me. I hope down the road, I can offer an example to those who are struggling."

In August, reports surfaced that Affleck, 46, had entered rehab for the third time. He had previously sought treatment in 2001 and 2017.

The next month, his younger brother Casey acknowledged in an interview with "Entertainment Tonight" that the "Batman v Superman" star was "trying to do the work and get it together," at least partially for his estranged wife, Jennifer Garner, their three young children.

"Ben is an addict and an alcoholic," Casey Affleck said. "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."

"Ben is trying to put it together," he added. "It can be a very hard thing to do."