On Thursday, the former The Hills star, 27, wrote a personal essay for The Huffington Post, in which he explained how he deftly kept his addiction a secret from his friends.
"A few years ago, I would host parties at my house in L.A. where there would be 50-100 people raging out of control. While everyone thought I was enjoying the party as much as they were, little did they know I was secretly going into the master bathroom and snorting as much coke and drinking as much alcohol as I could," Wahler reveals, adding that he became quite adept at keeping secrets.
"When I was done, I would grab a beer and get back into the party as if nothing happened," he adds.
Wahler – who appeared on Celebrity Rehab with Dr. Drew in 2010 and has completed several stints in rehab – says the death of Hoffman at 46 serves as a reminder of his own, intense battle with substance abuse.
"It brought me right back to those days of partying where my addiction was so bad that I didn't care who was around, how loud the music was, or how fancy the party was," Wahler writes. "It wasn't about the party at all – all I cared about was using and escaping reality even if it was by myself in a bathroom."
When the news of Hoffman's death broke online, Wahler recalls seeing a lot of negative comments about the actor, but he says people shouldn't be so quick to judge.
"I immediately began seeing comments all over the Internet about Hoffman's reported overdose – remarks to the effect of 'it's his own fault,' 'he got what he deserved,' and 'that's what you get for partying too much,' " Wahler writes.
"This wasn't a result of just feeling like using drugs or partying too much, but instead it was a snapshot into what the life of an addict can truly become."
Adds Wahler: "It can be incredibly hard for people who haven't been afflicted with addiction to understand the thinking and behaviors of an addict. I have witnessed just how close-minded some people can be when it comes to addiction, and combined with the passing of Phillip Seymour Hoffman, it only drives me to keep pushing to raise awareness," he writes.
"Unlike some other major celebrities who never made it out of active addiction alive, Hoffman was able to put a face to recovery. It's my hope that his passing isn't in vain, and that I can continue to educate more people about how important it is to not only get into treatment if necessary, but also to continually stay connected to prevent relapse."