Bethany Joy Lenz spent years trapped in what she calls a cult — and her One Tree Hill costars could tell something was wrong.

The actress behind Haley James Scott detailed her time in a high-control religious group in an interview with PEOPLE, noting that her costars on the WB teen drama recognized her struggle. "I could read it on people's faces," she said of her costars' reactions. "But the justification of it can't possibly be that I'm actually in a cult. It's just that I've got access to a relationship with God and people in a way that everybody else wants, but they don't know how to get it, and they're too afraid to be that vulnerable with each other. And so we've got it, and they just don't understand.' That's how you have to rationalize it."

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At one point, Craig Sheffer, who played Keith Scott, explicitly told Lenz that she was in a cult. "I was like, 'No, no, no. Cults are weird. Cults are people in robes chanting crazy things and drinking Kool-Aid," she remembered saying. "That's not what we do!'"

She gave more details about her experience in an August episode of her podcast Drama Queens, noting how her time filming One Tree Hill on the East Coast helped her eventually detach from the group. "In a lot of ways, One Tree Hill saved my life, because I was there nine months out of the year in North Carolina," she said. "I had a lot of flying back and forth, a lot of people visiting and things like that, but my life was really built in North Carolina. And I think that spatial separation made a big difference when it was time for me to wake up."

Elsewhere in the PEOPLE interview, Lenz explained how she ended up in the group in the first place. "I was looking for a place to belong that was also attached to a higher spiritual experience, and it looked so normal," Lenz said. "It looked so much like a lot of other Wednesday night Bible studies that I had been to in my life. And it was at first, and then it just morphed. But by the time it started morphing, I was too far into the relationships to really notice, and I was very young."

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The group began as a Bible study, but eventually began to revolve around the personality of a visiting pastor the actress calls "Les" — who eventually persuaded many members to move into a commune-esque community in Idaho. The group became increasingly insular, and encouraged Lenz to distrust anyone outside of it.

Lenz explained why the group appealed to her at the time. "We crave that kind of intimacy," she said. "The idea that someone out there says, 'No matter what you do or how badly you might behave or what dumb choices you make, I still love you, and I'm here for you.'”

Lenz first discussed her time in the group on her podcast last year. "I was in a cult for 10 years," Lenz said last July. "That would be a really valuable experience to write about, and the recovery — 10 years of recovery after that. So there's a lot to tell."

Now, she's making good on that idea with her book Dinner for Vampires, which details her time in The Big Family House church — an "abusive, high-demand group (a.k.a. cult)," she wrote on Instagram.

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Dinner for Vampires hits shelves Oct. 22.