One wrote: "Congratulations David. I'm considering giving it up completely myself (anxiety is always worse when I tipple)," and another commented: "Agreed. Three years for me. Hardest thing I've ever done. But also the best that thing that I've ever done."
A third remarked on Twitter: "It's been two years for me now - huge congratulations to you sir!"
When David decided to become sober, he told The Daily Telegraph he knew his drinking was an issue when his then four-year-old son, Leo, commented that "Daddy isn't well".
"I felt shame. I couldn't stand by and watch this be normalised with the next generation. I wanted to be a role model for him. I wanted to be the best father I could - I still do," he told the publication.
"So I quit alcohol, and I have never been happier. Now a year on, I have tripled my number of children and my resolve."
David's rocker dad Jimmy Barnes has also openly spoken about his addictions in his memoir Working Class Man.
During an interview with Now To Love, David's sister Mahalia Barnes revealed why her family is so open to sharing their stories.
"I think that being in the public profile, you do have less privacy, obviously. That's just how it works; it sort of comes with the territory.
"And obviously, there are things that you can choose to keep private, or you can speak openly. But when it comes to talking about things like alcoholism and drug addiction or domestic violence, that are generally kept secret and kept in the shadows, I think the more people that can publicly talk about that stuff, the better.
"It's not easy, it is vulnerable, but it's also really powerful and really important to do that because I think that there's a lot of stigmas that we have around those sorts of issues," said Mahalia.
If you or someone you know has been affected by any of the issues raised in this article, help is always available. Call Lifeline on 13 11 14 or visit their website.
This article originally appeared on our sister site, Now To Love.