Actress Shelley Duvall is going public with her battle with mental illness in a new interview with Phil McGraw.

The actress, best known for her roles in “The Shining” and “Popeye,” looks startlingly different in a video previewing her upcoming appearance on “Dr. Phil.”

“I’m very sick, I need help,” Duvall, 67, tells him.

The clip reveals she doesn’t think her “Popeye” co-star Robin Williams is dead, but is “shape shifting.”

Duvall also believes she is being threatened by “the sheriff of Nottingham” and has a "whirring disc" inside her. The preview notes she has been “leading a life of near isolation” for more than a decade.

RELATED: Kristen Bell: 'There's nothing weak about struggling with mental illness'

People who come forward about about their struggles are often applauded for reducing the stigma of mental illness. But the “Dr. Phil” show is coming under fire from some observers for featuring Duvall.

“Your exploitive use of Shelly Duvall is a form of LURID ENTERTAINMENT and is shameful,” Vivian Kubrick, the daughter Stanley Kubrick — who directed “The Shining” — wrote on Twitter.

RELATED: Woman's photos after panic attack aim to de-stigmatize mental illness

My Letter to you @DrPhil

Re: Your exploitive use of Shelly Duvall is a form of LURID ENTERTAINMENT and is shameful. pic.twitter.com/4f6MRTzr0A — Vivian Kubrick (@ViKu1111) November 17, 2016

"Shelley Duvall doesn't need Dr. Phil. Shelley Duvall needs actual help from a team of medical professionals," a columnist for Jezebel wrote.

But a mental health expert said Duvall is performing an important service by opening up about her experience.

"She is modeling for other people that you don't have to be ashamed of having a mental illness," Dr. Lloyd Sederer, former mental health commissioner of New York City and author of the new book "Improving Mental Health," told TODAY.

"Isolation is the worst thing that anybody can have or experience when they're sick with any disease... It's one step to not be isolated with friends and family and it's another step to then reveal your struggles to a large general audience or general public. That is courageous, in my opinion. That's not exploitative."

When celebrities open up about their struggles, it often makes mental health professionals' job easier because their patients can see that people who lead big productive lives can also have mental illness, Sederer said.

The main message is to get help.

"It's about not going it alone, because going it alone does not work," he noted.

The full interview is scheduled to air Friday.

Follow A. Pawlowski on Facebook, Instagram and Twitter.