In a surprisingly candid 2011 interview for Parade magazine, Monteith spoke openly about his history of substance abuse, describing his past drug use as "Anything and everything, as much as possible."
In that profile, which, because it was Parade, was probably printed opposite a crossword puzzle, Monteith revealed that he began skipping school at age 13 to drink alcohol. He dropped out of high school entirely at age 16, only return for the rest of his life on Glee at age 27.
Monteith told Parade he became clean at age 19 after he was caught stealing "a significant amount of money from a family member."
After the news of Monteith's latest admission to rehab broke, his girlfriend and co-star Lea Michele said in a statement "I love and support Cory and will stand by him through this. I am grateful and proud he made this decision."
E! reports that Monteith's treatment "will not affect the shooting of Glee's two remaining episodes of the season," which is the most important thing.