Lark Voorhies Battling Bipolar Disorder, Her Mom Tells PEOPLE

While most of the cast from Saved by the Bell have remained in the spotlight, Lark Voorhies has largely been out of sight.

The former teen star, known to a generation of fans as the fashionable Lisa Turtle, denies anything is wrong, but after a bizarre Yahoo! video went viral earlier this year, some questioned whether drugs played a role. Voorhies adamantly denied it. Instead, her mother says, she has been diagnosed with bipolar disorder.

In a series of interviews with PEOPLE, it was clear something wasn’t right. Voorhies, 38, would frequently stop mid-sentence and stare off, often mumbling to herself or to others who weren’t there.

“There are things that have traumatized her,” says Tricia, 64, who shares a home with her daughter in Pasadena, Calif. “I care deeply about my daughter and I want her to resume her life.”

PHOTOS: Saved by the Bell: Where Are They Now?

Voorhies says her “over-loving” mother worries about her, but there’s no need. She says she is not sick and keeps busy by working on low-budget indie productions, recording music and self-publishing her own books.

But what about the vacant stares and rambling moments?

“I have a strong spiritual sense,” she says. “You caught me in moments of pray [sic].”

For much more about Lark Voorhies’s sad spiral, what caused it and how her Saved by the Bell castmates reacted, pick up this week’s issue of PEOPLE