Saved by The Bell cast
Lark Voorhies played Lisa Turtle (far left) in the 90s show Saved by the Bell

Former Saved by the Bell star Lark Voorhies is battling with bipolar disorder, her mother has revealed.

The 38-year-old actress, who played Lisa Turtle in the 90s show, has been forced to lay low in recent years because of her mental illness, Tricia Voorhies said.

Unlike her co-stars, who continued to make a name for themselves, she has shied away from the spotlight following her diagnosis.

"There are things that have traumatised her. I care deeply about my daughter and I want her to resume her life," Voorhies told People magazine.

Lark made headlines earlier this year when she reportedly gave mumbled replies and kept seeming to zone out during an interview.

The Jehovah's Witness attributes her recent behaviour and long lapses of silence during conversations to "a strong spiritual sense" and insists that she was praying.

Her mother, however, said that the former teen star has refused to face up to her condition and see a mental health professional.

Lark now lives with her mother in California and has few friends. "They [physiatrists] don't explain it. They can't treat it. They don't know about it," he mother said.

Reflecting on her daughter's once successful acting career Voorhies said: "When Lark got on the stage a whole different side of her came alive."

Bipolar disorder, or manic depression, is a mental illness involving episodes of serious mania and depression. These can be severe mood swings accompanied by changes in emotions, thoughts, behaviours, physical health and functioning.