Cory MonteithJordan Strauss/Invision/AP

"Glee" star Cory Monteith was found dead in his room at the Fairmont Pacific Rim Hotel in Vancouver on July 13.

While the actor's cause of death has not been released, he spent the month of April in rehab for substance addiction -- an issue he'd previously addressed in his late teens and early 20s and discussed frankly in a 2011 interview with Parade.

When he was 19 and using "anything and everything, as much as possible," his mother and friends staged an intervention, he told the magazine. He ended up in rehab for the first time, but then "went back to doing exactly what I left off doing." However, it wasn't long before he hit bottom and then took steps toward recovery.

"I stole a significant amount of money from a family member," he confessed. "I knew I was going to get caught, but I was so desperate I didn't care. It was a cry for help."

Monteith drew on these personal struggles last September while filming the gritty cop drama "McCanick" in Philadelphia. In the movie -- his last -- Monteith played Simon Weeks, a drug-addicted criminal who's spent seven years behind bars on murder charges.

Director Josh C. Waller admits that Monteith, best known for playing jock-turned-singer Finn Hudson on "Glee," wasn't his first choice for the part. "In my mind, I was envisioning a teeny little drug guy [for the role], but Cory Monteith is this tall, strapping man," Waller told the L.A. Times on July 14. "But when I met with him, he wanted to do it so badly. 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 added, "He didn't say it was a cathartic experience, but you could sense it."

"McCanick" does not yet have a distributor, and Waller hasn't heard back from the Toronto Film Festival about whether or not the film has been accepted. "I want people to see the movie, because Cory deserves that," Waller said. "People would ultimately see that he had a lot more to offer artistically."

Monteith's autopsy is on the fast-track, reports E! News, with a Vancouver Police Department source telling the site to expect the toxicology results in two or three days.

Fox and the "Glee" producers released a statement expressing their shock and sadness -- sentiments echoed throughout Hollywood and on Twitter: "We are deeply saddened by this tragic news. Cory was an exceptional talent and an even more exceptional person. He was a true joy to work with and we will all miss him tremendously. Our thoughts and prayers are with his family and loved ones."

Cory Monteith and Lea MicheleJordan Strauss/Invision/AP

Monteith's girlfriend and co-star Lea Michele, 26, is quietly grieving, with her rep exhorting everyone to "kindly respect Lea's privacy during this devastating time."

Michele stood by Monteith when he entered rehab for a monthlong stay on March 31, and then expressed joy when he completed the stint in late April. "Today is a great day:)" she gushed on Twitter. "Love you all! Xo." Dating for a year and a half, the couple made their final red carpet appearance together at the Chrysalis Butterfly Ball on June 9.

Monteith, whose other movies include the 2011 rom-com "Monte Carlo" and the yet-to-be-released indie "All the Wrong Reasons," was in Vancouver visiting his mother at the time of his death.

[via L.A. Times, Parade, E! News, Us]
'Glee' Actor Cory Monteith Found Dead