Here’s something that I’m sure will be in no way controversial or argued about on Twitter. In a new interview, Quentin Tarantino revealed that Leonardo DiCaprio‘s Once Upon a Time in Hollywood character Rick Dalton is bipolar. The disorder is never mentioned by name in the film, and Rick himself is unaware he even has it. This confirmation lends a whole new layer to Rick and his problems, and attitude, throughout the film.

Did you interpret Rick Dalton’s wild mood swings in Once Upon a Time in Hollywood as a symptom of bipolar disorder? If so, congratulations: that was intentional. In a video interview with Vanity Fair (via THR), Tarantino and DiCaprio broke down the mental state of Rick Dalton and also revealed the real-life inspiration for the character and his condition: actor Pete Duel.

Duel starred on the ’70s Western series Alias Smith and Jones and committed suicide in 1971. Tarantino reveals that he researched Duel’s life for inspiration for Rick, who is also a TV Western actor, and discovered Duel had “a drinking problem due to self-medicating his apparent undiagnosed bipolar disorder.” In Once Upon a Time in Hollywood, Rick’s drinking problem is front and center. There’s even a scene where the actor goes back to his trailer during a shoot and has a complete breakdown, verbally chastising himself for getting too drunk the night before filming.

“Now, we already had Rick a drinker,” Tarantino says, “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 don’t have to revolve around the story of the scene.”

That said, if you didn’t pick up on Rick being bipolar, don’t sweat it. Tarantino also felt that Rick’s condition didn’t need to be “overtly” shown. “We never say the word ‘bipolar,'” he adds.

I’ll confess that I didn’t pick up on this myself when I saw Once Upon a Time in Hollywood – it’s clear the character is dealing with many issues, but I didn’t interpret them as bipolar. However, I’m now curious to see if it seems more overt when I see the film again. Once Upon a Time in Hollywood is now playing in theaters.