Speaking to TMZ, the 47-year-old admitted "it happens" but "it was a slip."
"I’m not going to let it derail me," he added.
On Saturday night, the tabloid website shared footage of Affleck leaving the Unicef Masquerade ball, trying to steady himself against a SUV on the streets.
Over the last few years, the Good Will Hunting star has struggled with alcoholism, having several stints in rehab, as recently as August 2018. Despite splitting from his wife Jennifer Garner a year ago, the actress has been supporting him through his recovery.
Seventeen years prior, news first broke of Affleck's troubles. Affleck completed a 30-day residential rehabilitation program for alcohol abuse – his publicist confirming the actor was tackling his addiction head on.
"Ben is a self-aware and smart man who has decided that a fuller life awaits him without alcohol. He is committed to traveling to a healthier road with the support of his family friends and fans."
"I went to rehab for being 29 and partying too much and not having a lot of boundaries and to clear my head and try to get some idea of who I wanted to be," Affleck later told The Hollywood Reporter.
"It was more a 'let me get myself straight,' before it became a rite of passage."
Some suggest that his early years may have provided the trigger for his struggles later on in life.
In 2012, in an interview with Barbara Walters, Affleck opened up about his childhood, watching his father drink away most days and the breakdown of his parents marriage.
"(My father) was an alcoholic... I did know that as a child. He drank a lot. My father was a – what did they call him – a real alcoholic. He, you know, drank all day, drank every day, and to his credit, he got sober ultimately," he told Walters at the time.
"He's been sober for several decades, which I think is pretty impressive."
Drug and alcohol use can both lead to, and result from, depression. And turning to substance use is often a mechanism for coping.
According to Beyond Blue, over 500,000 Australians will experience depression and a substance use disorder at the same time, at some point in their lives.
According to the Australian Guidelines to Reduce Health Risks from Drinking Alcohol, to reduce risk of disease, healthy men and women should drink no more than two standard drinks on any day.
If you, or someone you know, is struggling with their mental health, chat to a medical professional and reach out to a support hotline:
Lifeline on 13 11 14
SANE on 1800 187 263
Beyond Blue on 1300 22 4636