In 2006, Dr. Christopher D. Martin, a psychiatrist and admirer of Hemingway, published a pioneering study based on medical records, correspondence, biographies and interviews aimed at shedding light on the history of Hemingway's mental health.  

He found what he believed to be important evidence that Hemingway showed symptoms of bipolar disorder, in addition to acute personality traits and narcissism. 

In this report translated by Ahwal Al-Ma'rifah magazine, Martin's deepening also reveals the history of both Ed and Grace for depression, arguing that Hemingway likely carries a genetic tendency towards mental illness, in addition to his deep unresolved anger from his parents due to his upbringing.

 In his 2017 book titled Hemingway’s Brain, psychiatrist Andrew Farah argued that Hemingway’s symptoms resemble chronic traumatic encephalopathy (CTE) more than bipolar disorder. 

According to Farah, Hemingway was subjected to at least nine concussions or severe brain traumas during his life, which may explain his instability and increasing volatility. and the electric pulse treatments that Hemingway received in his last months may have actually worsened his psychological decline.

 However, there is another theory that sees that Hemingway suffered from hemochromatosis, which is a rare genetic disorder that leads to the inability to absorb iron. if left without treatment, it may lead to severe stress and loss of memory and depression and diabetes, all of which affect both Hemingway and other family members.  

But as with the other conjectures about the cause of Hemingway's mental struggles, the experts cannot be 100% sure of any diagnosis.

 Many members of Hemingway's family suffered later from mental health problems. Only five years after Hemingway's death, his sister Ursula, who was fighting cancer and continuous depression, died because of taking an intentional overdose of pills. Canary Leicester, the only brother of Hemingway and the youngest among the six siblings, was an author of several books, including the biography of his brother. and he shot himself in the year 1982, after years of health problems resulting from diabetes. as the youngest of Hemingway's children, Grery (also known as Gloria), suffered from manic depression. 

 Also two of Hemingway's granddaughters faced their own battles with mental health. Joan, nicknamed "Muffet" and the eldest daughter of Hemingway's first son, Jack, was diagnosed with manic depression. her sister Mart struggled to overcome learning difficulties, including dyslexia, and found fame as a model and actress in the late seventies. fascinated by the charm of her famous grandfather, she claimed later that she lived her fast life in imitation of him.  

 His granddaughter became a fierce advocate for mental health, as Mariel Hemingway, the younger sister of Mart and Muffet, was also an actress, and obtained an Oscar nomination for her work in Manhattan.  

She too suffered from depression in several stages of her life, unable to process the multi-generational mental illness. She was born after several months from Hemingway's death, and she remembers a dangerous and chaotic upbringing, where she and her sisters were told little about their famous grandfather but they suffered from a chaotic and dangerous upbringing at times.