April 9, 2016 | 9:17pm
Gloria Vanderbilt attends the premiere of the HBO documentary ‘Nothing Left Unsaid: Gloria Vanderbilt & Anderson Cooper’ on April 6.
“She’s still a mystery,” said one viewer at a Time Warner Center screening with guests including Lee Radziwill and Carolina Herrera. “[The film] glossed over the son. How do you live having a son who doesn’t want to see you?”
In the HBO doc about Vanderbilt and her CNN-anchor son, Cooper, there’s virtually no mention of Chris Stokowski — Cooper’s half-brother who vanished nearly 40 years ago after cutting himself off from the clan.
Vanderbilt’s eldest son, Stan, is in the movie. His and Chris’ father was conductor Leopold Stokowski, to whom Vanderbilt was married before Wyatt Cooper.
But Chris stopped speaking to his mom after a psychiatrist at the time, Dr. Christ L. Zois, allegedly influenced Chris’ relationship with his ex-fiancée April Sandmeyer.
When we contacted Sandmeyer on Friday, she told us Chris and Vanderbilt were once close: “She was his best friend. They were a really loving family . . . Everyone treated each other well and with respect. It’s probably painful, but as a mother, I think she respects [Chris’] privacy and [not mentioning him] is out of love for him. She knows he doesn’t want to be in the public eye. He doesn’t want the public’s attention.”
In 1993, Vanderbilt won a $1.5 million judgment against Zois and a lawyer she had accused of “preying on her wealth and emotional fragility.” There’s no mention of it in the movie.
“I was just horrified. I can’t reveal [what happened],” Sandmeyer told us of Zois’ influence. “It’s very sad and it’s very horrible and it has a lot to do with [the doctor] . . . [Chris] started to become estranged after the incident. I won’t divulge anything more.”
Sandmeyer (who referred to Gloria as “Mrs. Cooper” and said she hasn’t seen the film) added, “It’s a sensitive topic. [Zois’] relationship with Mrs. Cooper . . . wasn’t a normal doctor-patient relationship. She was too much under his influence.” Zois couldn’t be reached for comment.