'Nothing Left Unsaid' delves into Anderson Cooper's relationship with mother Gloria Vanderbilt

The documentary is the newest from HBO, which has also produced such acclaimed content as the documentary series 'The Jinx' and the film 'Going Clear.'

A new HBO documentary, “Nothing Left Unsaid,” which stars Anderson Cooper and Mr. Cooper’s mother Gloria Vanderbilt, explores the relationship between the two.

The film premieres on HBO on April 9 after being screened at the Sundance Film Festival, among other venues. 

Cooper said he was motivated to star in a documentary with his mother, who is 92, because he wanted to explore all possible topics with her. 

“Like the movie title says, I really didn’t want there to be anything left between us unsaid,” the journalist said in an interview with the Washington Post. “I wanted to finally ask her everything I wanted to know.” 

The movie is the newest documentary program to make its debut on HBO, which has previously been the home of such TV series as “The Jinx,” which fascinated viewers when it aired in early 2015; “Going Clear,” which won the Emmy Award for best documentary or nonfiction special; and “Mapplethorpe: Look at the Pictures,” a film about the photographer that debuted earlier this week. 

Boston Globe writer Matthew Gilbert noted last year that documentary TV in general has been both plentiful and of good quality recently, and that HBO has been an important part of this. 

“Many networks – HBO, Showtime, CNN, Al Jazeera America, ESPN – have been upping and improving their documentary content significantly,” Mr. Gilbert wrote. “...They are a prestige product, one that adds value to brand identity and, in the case of HBO, attracts subscribers."

Will viewers tune in for the documentary with Cooper and Vanderbilt? Some may do so because of the interest of the American public in some of the wealthiest families in the country. 

Newsday writer Verne Gay writes that those who can best remember the history of the Vanderbilt family over the past decades will likely most enjoy “Nothing.”

“’Nothing Left Unsaid’ will resonate with a viewer of a certain age – not the type of viewer who typically heads to HBO for their ‘Game of Thrones’ fix,” Mr. Gay writes. “They’re older, or old enough, to have witnessed most of the 20th century and the role Gloria Vanderbilt played around its edge, as the most famous child of the century, then one of the most famous socialites.”

But Vanity Fair writer Richard Lawson writes that the movie seems to lean too much into the belief that viewers will be enthralled by seeing members of the Vanderbilt family. 

“The film maybe too immediately buys into the mythos of Vanderbilt, and of all Great Families: a purchased idea that there is something innately worth knowing about them, an argument ‘Nothing Left Unsaid’ fails to make convincingly enough,” Mr. Lawson writes.