Mary Trump once stood up to her uncle Donald. Now her book describes a ‘nightmare’ of family dysfunction.

Mary L. Trump was embroiled in a feud over her inheritance two decades ago when her uncle Donald Trump and his siblings punched back in classic style. In an obscure court filing, they belittled her, alleging she “lives primarily off the Trump income” and is “not gainfully employed.”

Actually, Mary Trump had embarked on a new career. She studied patients with schizophrenia at Hillside Hospital on Long Island for at least six months during this period, meeting with an array of people who were delusional, hallucinatory and suicidal.

Over time, she deepened her studies of the disorder, contributed to a book on treating schizophrenia, wrote a dissertation on stalkers, and became a clinical psychologist. But not since she became part of the lawsuit in 2000 against her uncle has she spoken in detail about what she sees as the disorders of Donald Trump.

Now her silence could be coming to an end. Her book about her uncle — “Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man” — is slated to be published next month. The book is so potentially explosive that the Trump family is seeking to block publication, citing a confidentiality agreement that Mary Trump signed as part of a settlement about her inheritance. Mary Trump’s lawyer, Theodore Boutrous Jr., said the president is trying to “suppress a book that will discuss matters of utmost public importance.”

The publisher has not revealed specifics, and Mary Trump, 55, declined an interview request. But clues to her dark view of her uncle can be seen in lawsuits, and interviews with former colleagues and teachers, academic papers and a series of now-deleted tweets, including one that said her uncle’s election was the “worst night of my life.”

A description of the book from publisher Simon & Schuster suggests it will draw heavily on her studies of family dysfunction, with Mary using her clinical background to dissect “a nightmare of traumas, destructive relationships and a tragic combination of neglect and abuse,” including “the strange and harmful relationship between” her late father and Donald Trump.

The tragedy to which the book description alludes probably is informed by an event that infused both her life and that of her uncle: the death of her father — President Trump’s older brother Fred Jr. — of alcoholism when she was 16 years old.

Friends of her father’s told The Washington Post last year that they blame his death in part on the way he was treated by Donald Trump, and the president said in an interview last year with The Post that he regrets how he dealt with his brother.

President Trump told Axios that he didn’t think his niece was allowed to write the book because she signed the confidentiality agreement. The White House declined further comment.

Donald Trump’s brother Robert, who filed the petition to stop the book, said in the filing that Mary had agreed after accepting an unspecified financial settlement from the inheritance fight that she “would not publish any account” of her relationship with Donald Trump or his siblings. In a statement, Robert Trump said Mary’s decision to “mischaracterize our family relationship after all these years for her own financial gain is a travesty and injustice” to her late father, Fred Jr., and grandfather, Fred Sr., saying the family feels that “Mary’s actions are truly a disgrace.”

A Queens County Surrogate’s Court on Thursday denied the petition on grounds of lack of jurisdiction, but Robert Trump’s attorney said it would be refiled with the New York State Supreme Court.

Gilded life

From birth, Mary Trump was supposed to be set for a gilded life, a grandchild of Fred Sr. and Mary. Her father, Fred Jr., was the eldest of Fred Trump Sr.’s children, and he was expected to follow his father as the leader of the family business.

Mary was featured in society columns as a fashionably dressed young girl, and she spent time at her grandparents’ palatial home in Queens, watching her father feud with Donald and Fred Sr., who ran a New York City real estate company.

Much to the family’s consternation, Fred Jr. was interested in becoming a pilot for TWA, not in renting New York City apartments. After graduating from Lehigh University in 1960, he married a flight attendant named Linda Lee Clapp in 1962. He went to flight school and the couple had two children, including Mary, who was born in 1965.

Fred Jr. was already drinking heavily by the time Mary was born, and his troubles with alcohol may have caused him to give up his dream of becoming a commercial airline pilot, according to three former TWA employees who trained with him. Meanwhile, Donald Trump and Fred Sr. continued to pressure him to join the family business.

By the time Mary was 6 years old, her mother divorced Fred Jr. A family friend, David Miller, said in an interview that while Fred Jr.’s drinking played a role in the divorce, there was also a lot of pressure from Fred Sr., who Miller said disliked Linda. “She wasn’t welcomed into the family,” Miller said of Linda. Linda could not be reached for comment.

Fred Trump Sr. agreed at the time of the divorce to support Linda and his grandchildren, providing rent and $100 per week for expenses, plus $25 per week for Mary and Fred III, according to court records. Fred Sr. agreed to pay for Mary to attend a private school during her early years as well as her college and medical expenses.

On Sept. 26, 1981, Fred Trump Jr. died at 42 years old of a heart attack, which the family has said stemmed from alcoholism. Mary was 16 years old.

Carried a burden

Mary eventually attended Tufts University, where she studied the Southern novelist William Faulkner. In a seminar with English professor Alan Lebowitz, Mary and her 15 or so fellow students analyzed the Compson family portrayed in novels such as “The Sound and the Fury.

The Compsons bore some similarities to her own family: Like the Trumps, the Compsons migrated to the United States from Scotland, and the family was riven by dysfunction. At the time, Donald Trump was running his Atlantic City casinos, which went into bankruptcy, and preparing to divorce his first wife, Ivana, and marry Marla Maples.

Lebowitz said in a telephone interview that he has rarely had a student as exceptional as Mary Trump, who was featured in the Tufts commencement program as having won the award for top English student.

She was just as smart and accomplished as any I’ve taught in 40 years,” Lebowitz said. “She took a seminar on William Faulkner with me and she wrote two absolutely stunning papers, long, deep and elegant. We studied an enormously complex, interesting writer and she got deeply into it because she is a deep thinker.”

Lebowitz, who is retired, recalled that when she entered his classroom more than 30 years ago, he learned of the weight she carried.

“I knew that her father had been a very sad story and that she was carrying the burden of that story,” he said.

Mary and her brother Fred III had received some financial support over the years from the Trump family, and they expected to receive a significant inheritance from their grandfather, Fred Sr., who died in 1999. Mary and her brother had hoped they would get an amount close to what would have gone to their father, if he had lived, but they learned they were due to receive a lesser amount, and a probate fight ensued, court records show.

Mary and Fred III alleged that an unnamed person associated with the Trump family improperly engineered a change in the will of their grandfather, who had Alzheimer’s disease during his last years. Mary and her brother said the changes in the will were “procured by fraud and undue influence.”

Donald said at the time that he supported a cutoff of medical coverage that had been provided by a family company for Fred III’s son, William, who had cerebral palsy. Donald Trump told the New York Daily News that when he and his siblings were sued by Fred III and Mary, he felt, “Why should we give [William] medical coverage?”

Donald’s brother Robert said in a deposition that the family had given Mary annual gifts of $20,000, in addition to income from family ventures, estimating that Mary and Fred III annually received “close to $200,000 without either one lifting a finger at any time.”

Mary was livid about the family’s decision to cut off medical coverage for her nephew William. She told the Daily News at the time, “Given this family, it would be utterly naive to say it has nothing to do with money. But for both me and my brother, it has much more to do with that our father be recognized. He existed, he lived, he was their oldest son. And William is my father’s grandson. He is as much a part of that family as anybody else. He desperately needs extra care.”

In the 2000 lawsuit, Mary did not directly address her uncle Robert’s assertion that she was “not gainfully employed.” But it was around this time, after working on a master’s degree in English at Columbia University, that she served in a voluntary role in the study of schizophrenia patients, assisting senior social worker Rachel Miller at Zucker Hillside Hospital in Glen Oaks, N.Y.

Miller said Mary Trump showed an intense interest in understanding what drove people into psychological dysfunction. “She went into a situation that is hard to see. Many doctors and social workers couldn’t go there, it was so frightening to see somebody losing their mind,” Miller said.

Mary Trump accompanied her in visits with patients who were typically 16 to 25 years old and experiencing their first episodes of schizophrenia. “She had her life set on doing what she wanted to do, which was to be a psychologist,” Miller said.

Later, when Miller needed help on a book she co-wrote, “Diagnosis: Schizophrenia,” about the study, she said Mary worked long hours to help her research and write the manual, which became popular in the field and with families of people with the disease.

‘Worst night of my life’

Mary Trump continued her studies at Adelphi University, where she earned a master’s degree in psychology in 2001, a master’s in clinical psychology in 2003, and a doctoral degree in clinical psychology in 2010, a school official said.

In her 205-page dissertation, “A Characterological Evaluation of the Victims of Stalking,” she examined whether there were certain personality characteristics that made some people “more vulnerable to being victims of stalking by an intimate partner.”

A few years later, Mary founded a company called Trump Coaching Group, which provided wellness and fitness services on Long Island.

An archived version of the now-deleted company website said the company focused on nurturing relationships. It said Mary’s interest stemmed “from her own struggles as an athlete with asthma which have given her a true appreciation for the extent to which physical well-being is vital to psychological and emotional well-being.”

One of the coaches listed as a team member said the company didn’t develop much beyond the creation of the website. Paige Crosby, who said she participated in a year-long training program with Mary Trump to become a life coach, recalled her talking about her “hurt feelings” from her “sour relationship” with Donald.

As Donald Trump announced his candidacy in 2015, Mary Trump does not appear to have said anything publicly about him.

But when it became clear that her uncle had won the presidency, she took to Twitter. “Worst night of my life,” she wrote at least 12 times in tweets that have been deleted recently. She wrote that “We should be judged harshly. . . . I grieve for our country.”

Mary Trump’s publicist, asked to verify that Mary wrote the tweets, declined to comment.

Last year, according to corporate filings, Mary created a company that echoed the name of the tragic family in Faulkner’s novels: Compson Enterprises. In an initial listing for her book, designed to keep the project a secret, her name was given as Mary Compson.

Now Mary Trump appears to hope that, with an assist from the publication of her book, the next presidential election will turn out differently from the last. She foreshadowed it at 4:07 a.m. on Nov. 9, 2016, shortly after her uncle was declared the president-elect, when she tweeted simply: “2020.”