Donald Trump’s extraordinary character and outrageous behaviour “threaten the world’s health, economic security and social fabric” and were shaped by his “high-functioning sociopath” father during childhood, according to a bombshell book written by the president’s niece.

Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man by Mary Trump will be published next Tuesday, 14 July. The Guardian obtained a copy.

As well as an extended consideration of familial dysfunction which she says shaped Donald Trump, Mary Trump alleges multiple instances of shocking behaviour by the president as a younger man, including academic cheating to get into a prestigious business school, and brutal treatment of women.

In the acknowledgments, Mary Trump thanks her aunt, Maryanne Trump Barry, “for all of the enlightening information”. Maryanne Trump Barry, the president’s sister, is a federal judge who retired in 2019, thereby ending an inquiry into fraudulent tax schemes.

Mary Trump was reportedly a key source for the New York Times’ Pulitzer-winning reporting on Trump family tax affairs. The US supreme court is currently considering whether the president’s tax and financial records should be released to the public.

On Tuesday afternoon, the White House press secretary, Kayleigh McEnany, said the president had “no response, other than it’s a book of falsehoods … ridiculous, absurd allegations that have absolutely no bearing in truth”.

The White House, she said, “had yet to see the book but it’s a book of falsehoods”.

Donald Trump’s niece writes her study of his character from the perspective of a trained clinical psychologist.

“Child abuse is, in some sense, the expectation of ‘too much’ or ‘not enough’,” she writes. “Donald directly experienced the ‘not enough’ in the loss of connection to his mother at a crucial development stage.

“… Having been abandoned by his mother for at least a year, and having his father fail not only to meet his needs but to make him feel safe or loved, valued or mirrored, Donald suffered deprivations that would scar him for life.

“The personality traits that resulted – displays of narcissism, bullying, grandiosity – finally made my grandfather take notice but not in a way that ameliorated any of the horror that had come before.”

Donald Trump’s mother, also called Mary, suffered health problems resulting from an emergency hysterectomy. That, she writes, left the future president and his siblings dependent on their father, Fred Trump, a New York property developer who died in 1999.

Mary Trump describes Fred Trump as a “high-functioning sociopath” and details his bullying, antisemitism, racism, sexism and xenophobia – all traits the president is regularly accused of.

Fred Trump’s oldest son, also called Fred, died in 1981 in his early 40s, from the effects of alcoholism. His daughter writes that Donald Trump’s character was formed by watching the traumas inflicted on and suffered by his older brother.

The man that emerges is ruthless and utterly self-centered, she writes. In a section on Trump’s education, Mary Trump describes how he paid someone else to take his SAT tests for him.

“Donald, who never lacked for funds, paid his buddy well,” she writes, of “Joe Shapiro, a smart kid with a reputation for being a good test taker”.

The scheme included Trump’s brother putting in a word at the Wharton Business School, at the University of Pennsylvania. Mary Trump writes that it “may not even have been necessary”, as “in those days, Penn was much less selective than it is now.”

Other than Maryanne Trump Barry, the judge, Donald Trump’s surviving siblings are Robert Trump, a businessman, and Elizabeth Trump Grau, a retired banker.

Robert Trump has sued Mary Trump in New York, claiming a non-disclosure agreement signed in 2001 over Fred Trump Sr’s will precludes publication. The president has said he thinks the NDA, which includes Maryanne Trump Barry, means the book cannot come out. Mary Trump has argued in appeal filings that the NDA was based on fraudulent financial information. A hearing was scheduled for Friday.

Simon & Schuster was dropped from the suit and subsequently brought publication forward by two weeks.

Arguing on first amendment grounds for the freedom of speech, lawyers for Mary Trump have pointed to how the president has “contributed to his and his family’s notoriety in a variety of ways, including as the author of nearly 20 books on topics including his family, his wealth, his businesses and his own life.”

Mary Trump details how she was contracted to ghostwrite one of those books, The Art of the Comeback.

“A few weeks after Donald hired me,” she writes, detailing an experience familiar to many of the president’s business partners and contractors, “I still hadn’t gotten paid.”

Trump’s notorious treatment of women is also discussed. Mary Trump says that when her uncle provided material, it was “an aggrieved compendium of women” – Madonna and the ice skater Katarina Witt among them – “he had expected to date but who, having refused him, were suddenly the worst, ugliest and fattest slobs he’d ever met.”

“I stopped asking him for an interview,” she writes, adding that on a visit to Trump’s Mar-a-Lago resort in Florida to work on the book, she was wearing a bathing suit when Trump looked at his niece and said: “Holy shit, Mary. You’re stacked.”

Trump has been accused of sexual misconduct and assault by more than 20 women. He denies all such claims.

Trump fired his niece from the project. Characteristically, Mary Trump writes, he had someone else tell her.

Mary Trump has expressed opposition to her uncle on social media. In her book, she writes of turning down an invitation to his 2016 election night party, because “I wouldn’t be able to contain my euphoria when [Hillary] Clinton’s victory was announced, and I didn’t want to be rude.”

Of the day after Trump’s victory, she writes, “I was wandering around my house, as traumatized as many other people but in a more personal way: it felt as though 62,979,636 voters had chosen to turn this country into a macro version of my malignantly dysfunctional family.”

Like a White House memoir by the former national security adviser John Bolton, also published by Simon & Schuster, Mary Trump’s book is now in the public realm.

In the words of a federal judge in Washington who declined to block Bolton’s book, “the horse is out of the barn”.