Picoult remembers when everyone seemed to praise her novel Nineteen Minutes, a 2007 bestseller about a school shooting, that now tops a PEN America list of the books most banned in schools.
"Not only was it recommended for young adults to read, but it was on the curriculum in schools where it's now banned," the author said.
On Friday, PEN issued a report that expands upon numbers released in September for Banned Books Week, when libraries and stores around the country highlighted censored works.
PEN compiled more than 10,000 cases of books temporarily or permanently removed during the 2023-2024 academic year, roughly four times higher than for 2021-2022.
The bans affected around 4200 individual titles, compared with around 1600 two years ago.
More than 80 per cent of the bans came in Iowa and Florida, states that have passed laws restricting school books.
Around 4500 were removed in Florida, and more than 3600 in Iowa, according to PEN.
"What students can read in schools provides the foundation for their lives, whether critical thinking, empathy across difference, personal well-being, or long-term success," PEN's director of its Freedom to Read program, Kasey Meehan, said in a statement.
"The defence of the core principles of public education and the freedom to read, learn, and think is as necessary now as ever."
Besides Nineteen Minutes, books most frequently removed include John Green's Looking for Alaska, Alice Walker's The Colour Purple, Margaret Atwood's The Handmaid's Tale, Toni Morrison's The Bluest Eye and several novels by romantasy favourite Sarah J. Maas.
Many of the works had themes of sex, race or gender identity.
Picoult noted that objections to her book centred on a single page referring to a date rape.
"There was nothing gratuitous about it. It's not porn," she said.
"I think that some people are unhappy because it makes you look at the world in a different way. That's what's behind a lot of the bans."
AAP