The late "Glee" star also deals drugs in the upcoming drama, "McCanick"
The same day the Canadian authorities revealed that actor Cory Monteith died due to mixed drug toxicity involving heroin and alcohol, the director of his last film released the first clip of him playing a drug addict in "McCanick."
Waller told the Los Angeles Times on Sunday that Monteith was not shy about his demons, and channeled his addiction experience for the role he shot last September in Philadelphia.
"He was very vocal about his past, and said he wanted to tap into things from his youth that he hadn't been able to use as an actor yet," Waller said.
Monteith, who was found dead in a Vancouver hotel room on Saturday, has been open about his struggles with addiction. In a 2011 interview, he revealed he first sought treatment at the age of 19 after his friends and mother staged an intervention. Last April, he once again entered rehab for substance addiction.
"He didn't say it was a cathartic experience, but you could sense it," Waller added.
While "McCanick" was the last film Monteith shot, he also stars in writer-director Gia Milani's upcoming comedy, "All the Wrong Reasons."
Watch a preview of Monteith's final performance, below: