(CNN) Ben Affleck posted an Instagram statement Thursday in which he revealed that he recently completed a 40-day stay at a treatment center and continues his outpatient care for alcohol addiction.
"The support I have received from my family, colleagues, and fans means more to me than I can say," he wrote. "It's given me the strength and support to speak about my illness with others."
Affleck, 46, entered rehab back in August. He previously sought treatment in 2001 and 2017.
"Battling any addiction is a lifelong and difficult struggle," Affleck wrote. "Because of that, one is never really in or out of treatment. It is a full-time commitment."
He added: "I am fighting for myself and my family."
Affleck has three children with actress Jennifer Garner.
Garner and Affleck filed for divorce in 2017, two years after they separated. The two remain friendly, however.
Garner was photographed with Affleck on the same day he recently reported to rehab.
"So many people have reached out on social media and spoken about their own journeys with addiction. To those people, I want to say thank you," Affleck said. "Your strength is inspiring and is supporting me in ways I didn't think was possible. It helps to know I am not alone."
Affleck said he's "had to remind myself, if you have a problem, getting help is a sign of courage, not weakness or failure."
The actor, who was set to write and direct a standalone Batman film before leaving his directing role last year, said he hopes that "down the road I can offer an example to others who are struggling."