Shawn Hornbeck and parents
Speaking out for the first time, Shawn Hornbeck says his four years of being held captive was a nightmare so horrendous it would "send psychiatrists insane."
"I'm not gonna lie – there were times when it seemed like I was better off dead," Hornbeck, 17, tells CBS correspondent Troy Roberts in an interview airing Sept. 27 on 48 Hours Mystery.
Hornbeck was kidnapped in October 2002 and held in the home of pizza parlor worker Michael Devlin, 43, until the teenager was rescued in January 2007 after Devlin kidnapped another boy, 13-year-old Ben Ownby. (Devlin was given 74 life sentences).
Hornbeck spent most of his first month bound to Devlin's futon; he was constantly sexually abused.
"There wasn't a day when I didn't think he was just gonna kill me," says Hornbeck, adding that his story features "a lot of gory, nasty details that a lot of people really can't handle."
For more on Shawn Hornbeck's ordeal, pick up PEOPLE on newsstands Friday