Olivia Rodrigo had to "walk out" of new movie 'Beau is Afraid'.

The 20-year-old star admitted she struggles with horror movies, and she has described Joaquin Phoenix's surreal tragi-comedy horror - which was written and directed by Ari Aster - as a "bad acid trip".

Speaking to Phoebe Bridgers for Interview magazine, she said: "I convince myself that I see shit after I come home from watching Insidious or something.

“Also, I watched that new Ari Aster movie 'Beau Is Afraid' and I got so scared. I literally had to walk out of the theater.

"I have never had such a visceral reaction to a movie in my life. It felt like a bad acid trip.”

Phoebe agreed, saying: "[It was] the scariest movie I’ve ever seen, but I was laughing the entire time.”

Olivia added: “That’s the only reasonable reaction. Your body just can’t process it. You have to laugh.”

The movie - which also stars the likes of Nathan Lane, Amy Ryan, Kylie Rogers, Richard Kind, Michael Gandolfini and more - focuses on "a paranoid man [who] embarks on an epic odyssey to get home to his mother".

The 'High School Musical: The Musical: The Series' star isn't the only person struggling with the movie, and Phoenix himself previously warned viewers to "not take mushrooms" before watching.

He told Fandango: "I was told from someone in college that there was this college thread amongst friends, a challenge they were going to take mushrooms and go see this movie.

“And I just wanted to make a public service announcement and say do not take mushrooms and go see this f****** movie.”

Meanwhile, filmmaker Aster insisted the movie "benefits from going back" for another viewing.

Speaking to Empire magazine, he explained: "I don’t think you quite know what it is until you’ve gone all the way through.

"I imagine that the second viewing would be hopefully rich in a way that the first one can’t. It’s designed to be wrestled with.

"I consider the film to be a picaresque, and I think part of that tradition is a certain irreverence towards the integrity of any sort of narrative structure. The film is designed to kind of shapeshift a lot.”