Quentin Tarantino Explains Choice to Make Leonardo DiCaprio's 'Once Upon a Time in Hollywood' Character Bipolar

Rick Dalton Once Upon a Time in Hollywood - Photofest - H 2019
It's never spelled out in the film, but aging actor Rick Dalton has hidden struggles.

Quentin Tarantino has pulled back the curtain a little more on Leonardo DiCaprio's character in Once Upon a Time in Hollywood.

In a recent video from Vanity Fair, the Oscar-winning director (accompanied by the actor) explained the decision to make the fictitious aging TV star Rick Dalton bipolar and the origins of that development.

Tarantino, a well-known fan of classic film and TV, would tell DiCaprio during production about Dalton's past exploits based on actual characters in shows. After a while, DiCaprio needed more to find his character.

"In a very nice way, Leo would say, 'Okay, all of that is well and good about all this minutia, [but] I need something to act,'" the filmmaker said.

In one instance, Tarantino told DiCaprio a story about the late actor Pete Duel, who starred on the 1970s Western series Alias Smith and Jones (a childhood favorite of Tarantino's).

The 31-year-old Duel died by suicide in 1971. Through his research, Tarantino learned the actor had a drinking problem due to self-medicating his apparently undiagnosed bipolar disorder.

"Leo got that," Tarantino said. "Now, we already had Rick a drinker, but the whole thing about undiagnosed bipolar and not knowing how that works, and the weird pendulum swings of emotion you would have … that became a really interesting thing that we thought Rick could deal through. And that gave Leo a good, solid ground in which to work and build a character and have a subtext going on inside of scenes that doesn't have to revolve around the story of the scene."

Rick has numerous breakdowns in the film, the largest outburst being in his trailer after forgetting his lines during a scene for his guest spot on a TV series.

DiCaprio said Rick being bipolar did not need to be "overtly" shown to the audience. "We never say the word 'bipolar,'" Tarantino interjected.

Also starring Brad Pitt and Margot Robbie, Once Upon a Time in Hollywood, Tarantino's ninth film, bowed Friday. The Sony pic has been met with critical and box office success.

Watch the full video with Tarantino and DiCaprio, below.