On Saturday, December 4, 1926, a green Morris Cowley motorcar stood abandoned in a roadside ditch near the city of Guildford, England. The car belonged to the renowned author Agatha Christie, who had apparently disappeared without a trace. But after missing for 11 days, she turned up in a hotel in Harrogate, a spa town in Yorkshire 200 miles north of Guildford. Christie was unable to explain what had transpired during the intervening time period, nor is this mysterious episode mentioned in her autobiography. Unlike those in her many books, this mystery remains unsolved.

Is it possible that Christie suffered from what is called retrograde amnesia as a result of an automobile accident and was no longer capable of remembering the event? Was she, by disappearing, perhaps exacting revenge on her unfaithful husband? Or was this just a clever public relations ploy aimed at promoting her latest novel?

The drama began in April 1926, when Christie’s mother died. According to Christie’s biographer Janet Morgan, the death hit her very hard. At the time her husband, Colonel Archibald Christie, known as Archie, was on a business trip. On returning, he informed his psychologically fragile wife that he had fallen in love with a woman named Nancy Neele. For a while the Christies stayed together for their daughter’s sake, even moving together to Styles, her house in Sunningdale, in the county of Berkshire. All the while, however, Archie maintained his affair with Neele.

On the morning of December 3, Agatha and Archie had a domestic argument. She drove off in the car that was found the next day near Guildford. Christie, meanwhile, had checked into the hotel in Harrogate—under the name Neele—and listed her place of residence as Cape Town, South Africa. While news of her disappearance sped around the globe and newspapers everywhere featured her photograph, Christie, alias Neele, took the cure, relaxing in the atmosphere of the spa. By all appearances, she seemed happy and content, not at all fearful of being discovered by the mob of journalists who were hot on her trail.

“I Do Not Think She Knows Who She Is”

In fact, two other esteemed writers, Sir Arthur Conan Doyle and Dorothy Sayers, joined in the search. One evening Christie was recognized in the hotel by a local musician, Bob Tappin. He notified the police, and two days later Archie confirmed that the lady in question was indeed his wife. Archie was also the one who first raised the question of a loss of memory. In a newspaper interview on December 15, 1926, he declared, “She has suffered from the most complete loss of memory, and I do not think she knows who she is. She does not know me, and she does not know where she is. I am hoping that rest and quiet will restore her. I am hoping to take her to London tomorrow to see a doctor and specialist.”

In her novel The Lost Days of Agatha Christie, American therapist Carole Owens doubts this was a case of amnesia because the author clearly remembered the name of her husband’s lover, at least to the extent that she used it in Harrogate. This argument, however, is less than cogent because we know today that partial amnesia can occur and that it can affect certain memory systems such as episodic memory (of events) while leaving semantic (factual) memory intact. In other words, the crime novelist could well have lost all recollection of how she got from Guildford to Harrogate while nonetheless retaining the name of her rival. In addition, as an eyewitness reported, she had no trouble playing cards with other guests in the hotel lobby and even dancing. This means her procedural memory, which enables people to perform actions such as dancing or cycling automatically, was apparently unaffected.

In addition, short-term memory lapses such as transient global amnesia lasting no more than 24 hours are known to occur. Although affected persons may be as attentive and awake as ever, their access to previously acquired memories may be disturbed (retrograde amnesia). Nor are they able to store new information (anterograde amnesia). This type of amnesia may be caused by severe emotional stress, but in such cases, people almost always retain knowledge of who they are and of those with whom they are close. This suggests Christie probably did not suffer from this syndrome.

Writer Agatha Christie and her second husband, Max E. L. Mallowan, pose in March 1946 on the grounds of their home, Greenway House, in the county of Devon in England. This marriage lasted until Christie’s death in 1976. Credit: Getty Images

Writing in 2003 in Practical Neurology, psychologists Mireia Pujol and Michael Kopelman, both then at King’s College London, discussed the possibility that Christie may have experienced psychogenic amnesia secondary to trauma. This memory disorder, also called dissociative amnesia, generally lasts for a few hours, days or even months and affects primarily memories of those events that occurred immediately before the traumatic experience. Such amnesia may be triggered by catastrophic news, a fight, financial ruin or war.

In 1935 two psychiatrists writing in Archives of Neurology and Psychiatry described the case of a woman who left her husband for another man. After a week, she decided to return home as if nothing had happened. The sheer impossibility of this endeavor caused her to consider suicide, just before she developed amnesia.

Fragments of Memories

Such a psychogenic “flight syndrome” exhibits some striking overlap with organic amnesia. In both types, for example, fragments of prior memories may remain but are covered by a blanket of forgetting. In neurological memory disorders, however, memories from the more distant past tend to be retained, whereas newly absorbed information is lost. In syndromes caused by psychological stress, this pattern is generally reversed: the memory of recently experienced events is retained, whereas older memories disappear.

This presumably has neurophysiological causes: Although freshly formed memory traces are largely limited to the hippocampus in the temporal lobes, information that has been repeatedly called up over time is activated by links with other regions of the cortex, such as the frontal lobe. The hippocampus is often damaged during brain injuries caused by an accident or by organic causes. When linked regions are intact, however, shards of older memories may make their way into consciousness. Acute stress, on the other hand, decreases neural processing in the frontal lobe, which is involved in retrieving episodic, autobiographical and factual knowledge. Because, among other things, certain regions of the frontal cortex are responsible for inhibiting memory, stress-related changes in the activity of the frontal lobe may more easily impair personal memories and semantic information acquired long ago than does damage to the hippocampus.

According to Kopelman, cases of total memory loss of the kind often seen in movies is practically unknown. Whether amnesia is caused by an accident or stress, the idea that patients would cease to have any knowledge of who they are, where they are or the identity of their spouse is largely a fiction. But because this cliché has been so popularized by the media, experts are easily able to distinguish simulated amnesia when they see it.

Was It All Just Made Up?

Gwen Robyns, author of The Mystery of Agatha Christie, believes Christie was in full control of her memory during the entire episode of her disappearance. As Robyns sees it, Christie was intent on exacting revenge on her husband by prolonging the separation. Another Christie expert, journalist Jared Cade, believes it is entirely plausible that Christie simply intended to make her husband’s liaison with Neele as stressful as possible. Cade asserts that Agatha later admitted to her husband that she had staged the entire disappearance. Edgar Wallace, another writer colleague of Christie’s who worked for the British tabloid the Daily Mail, claimed that this was a case of revenge for having been betrayed.

Her disappearance became a major public cause célèbre and, as Cade avers in his book, had political implications as well. During a parliamentary debate, Labor Party MP William Lunn asked a question that amounted to heresy: How much money had the state spent searching for this star author? Home Secretary William Joynson-Hicks estimated police costs at less than £13—about $1,000 in today’s dollars. To which Lunn responded, “Who is going to compensate the thousands of people who were deliberately misled by this cruel hoax?” Joynson-Hicks declined to answer.

But feigning the kind of amnesia from which Christie apparently suffered is much more difficult than it might appear. Most people have no idea what symptoms they should or should not display. A simple test of episodic, semantic and procedural memory would quickly diagnose fakery.

Given the many questions that are unresolved 90 years after Christie’s disappearance, it remains a mystery. Nor is it at all clear whether her amnesia was staged or was in fact caused by stress or some organic disorder. With regard to human memory, in which reality and fiction so easily become intermingled in an inextricable mélange, matters are never as straightforward as Christie, speaking of her mysteries, would have you believe: “The simplest explanation is usually the right one.”

Editors’ Note: This story is a translation of an article from Scientific American’s Italian-language sister publication, Mente&Cervello.

Diagnostic Criteria: Dissociative Amnesia

According to the World Health Organization, the main feature of this condition is “loss of memory, usually of important recent events, that is not due to organic mental disorder, and is too great to be explained by ordinary forgetfulness or fatigue. The amnesia is usually centered on traumatic events, such as accidents or unexpected bereavements, and is usually partial and selective. Complete and generalized amnesia is rare, and is usually part of a fugue.... If this is the case, the disorder should be classified as such. The diagnosis should not be made in the presence of organic brain disorders, intoxication or excessive fatigue.”

In other words, Agatha Christie could have suffered from a dissociative fugue, or state of psychological flight. Persons with this disorder exhibit all the symptoms of dissociative amnesia. Additionally, a person suffering from this disorder may seek to move well beyond his or her usual sphere of travel. And although the individual may suffer amnesia during a fugue state, behavior may seem completely normal to outsiders.

Source: International Statistical Classification of Diseases and Related Health Problems, 10th Revision. 2016 Version. World Health Organization, 2016