American Psycho author Bret Easton Ellis has said he will always be defined by his iconic, psychopathic antihero Patrick Bateman, and revealed that his character would be “embarrassed” by Donald Trump today after revering him in the novel.

Ellis’s iconic book about 1980s consumerist culture and masculinity was published in 1991; it was dropped the previous year by publisher Simon & Schuster due to concerns about the content and eventually published by Vintage Books (now Penguin Random House). It was hugely divisive due to Bateman’s detatched dabblings in rape, torture, cannibalism, murder and necrophilia; in the Guardian, Joan Smith called it “nasty, brutish and long” and the New York Times deemed it “the most loathsome offering of the season”.

Marking the 25th anniversary of the book in an interview with Rolling Stone, Ellis revealed he found the book’s most violent scenes “depressing and gross to write, but at the same time, exciting”, and said his initial editor wanted to remove most of it. “He thought it was disgusting and that I was going to be ashamed of it five years down the road. Now I honestly don’t remember a lot of what I put in there.”

In the novel, Bateman is a huge fan of the now-presidential candidate Donald Trump, at one point attending a U2 concert because he is told Trump likes them. He recommends Trump’s how-to book The Art of the Deal to a detective investigating the disappearance of someone Bateman murdered. But Ellis said in the interview that if Bateman was voting today, he “may be disappointed by how Trump is coming off and who he’s connecting with”.

In an interview with Rolling Stone, Ellis says: ‘Trump today isn’t the Trump of 1987… Now he seems to be giving a voice to white, angry, blue-collar voters. I think, in a way, Patrick Bateman may be disappointed by how Trump is coming off.’ Photograph: ddp USA/REX/Shutterstock

“Trump today isn’t the Trump of 1987. He’s not the Trump of Art of the Deal,” Ellis said. “He seemed much more elitist in 87, 88. Now he seems to be giving a voice to white, angry, blue-collar voters ... To the guys that I was talking to in the Eighties when I was researching American Psycho, Donald Trump was an aspirational figure. That’s why the jokes are throughout the book. It wasn’t like I pulled that out of my hat; that was happening. And so I just thought it was funny that ‘OK, well, Patrick Bateman’s gonna be obsessed with Donald Trump. He’s gonna want to aspire to be Donald Trump.’ And I don’t know if he would think that today.”

Christian Bale as Patrick Bateman in the film adaptation of American Psycho. Photograph: Moviestore Collection / Rex Feat

In an interview with the Guardian in 2010, Ellis claimed it never occurred to him that American Psycho would cause offence: “No, not at all. That was shocking.” That same year, Ellis revealed that he had previously lied about the inspiration behind Bateman being a combination of his own father, Robert Ellis, and American bankers. “Patrick Bateman was about me,” he said, in an interview with Australian magazine Three Thousand. “I didn’t want to own up to the responsibility of being Patrick Bateman, so I laid it on my father; I laid it on Wall Street.”

Bateman appeared in other books by Ellis: a small, pre-Psycho appearance in The Rules of Attraction (1987), a cameo in Glamorama (1998) and Lunar Park (2005), a novel Ellis said started as a homage to Stephen King but became an autobiographical analysis of the fame that came with creating Bateman. “I will always be defined by Patrick Bateman. I don’t think there’s ever another character I will create that will have that kind of impact,” he told Rolling Stone. “I thought it was fun to grapple with that idea, but I really don’t know if there’s any way I would reference it now.”

Ellis said he had no problem with American Psycho being adapted into the film in 2000 starring Christian Bale, or the musical version in 2013, with ex-Doctor Who actor Matt Smith playing Bateman in London, and now Benjamin Walker for the show’s new run on Broadway. “I don’t really see what the drawback is,” Ellis said. “Every now and then you see things like, ‘Dear God, this is a musical. How did Bret Ellis let this happen?’ Well, Bret Ellis didn’t really let anything happen. Ultimately, I don’t have a problem with it.”

Much of the book’s significance lies in the shocking twist that Bateman’s violent behaviour may have never happened at all, and are just the imaginings of a unreliable narrator. Ellis revealed to Rolling Stone that he still has not decided if Bateman does what he says he did in the book. “When I was writing the book, I couldn’t make a decision. That was what was so interesting to me about it. You can read the book either way.”

Due to the nature of its content, American Psycho is still sold shrink-wrapped in Australia and New Zealand, a practice Bret Easton Ellis has called “adorable” and “cute”. Last year, a bookstore in Adelaide was visited by local police after it displayed the book unwrapped on a shelf.