Australasian Science: Australia's authority on science since 1938

The Mystery of Agatha’s Amnesia

By Tim Hannan

A popular fictional theme, psychogenic amnesia is a possible consequence of stress or trauma.

A sudden attack of amnesia for one’s own identity has been popular grist for the Hollywood mill, with films such as Total Recall, X-Men and the Jason Bourne series all revolving around the protagonists’ inability to recall much of their personal histories. Indeed, the number of movies about this unusual type of amnesia has exceeded the count of well-documented cases in the psychological literature, and its apparent rarity and inexplicability has led to suspicions that sufferers were fabricating their symptoms – as happened to the crime novelist Agatha Christie in 1926. A new review in the journal Brain has identified more than 50 cases in a 20-year period at one London hospital, suggesting that this form of amnesia may not be quite as rare as previously thought.

Amnesia is most commonly observed after a neurological illness or injury, or as a consequence of the onset of dementia. In such cases, the person loses the ability to lay down new memories (anterograde amnesia) and struggles to recall certain memories from before the onset of the condition (retrograde amnesia). Usually, the amnesia for past events relates to specific facts or details, and is more prominent for recent events rather than long-held and well-learned facts. The neural damage is typically located in the medial temporal lobes, including the hippocampus.

In contrast to these “organic” forms of amnesia, “psychogenic” or “dissociative” amnesia is understood to arise as a result of trauma or other psychological stress, and involves forgetting personal information. The sufferer is able to recall and utilise her long-held general knowledge and skills to engage with people, objects and the environment, but is unable to recall her name, family members, residence, job or other personal details.

The best-known case of psychogenic amnesia, Agatha Christie, went missing for 11 days after disappearing suddenly from her home. Her car was later discovered abandoned 50 km away, and she was eventually located in a hotel in Harrogate 350 km to the north. At that time she reportedly lacked any recall of the intervening period and didn’t recognise her husband. Newspaper coverage at the time questioned the authenticity of Christie’s claims. No doubt her fame as a writer of crime fiction encouraged such scepticism.

However, a new review by clinicians from a London hospital demonstrates that her symptoms were quite consistent with those observed in well-documented cases of psychogenic amnesia. They identified 53 cases admitted to the hospital between 1990 and 2008, with examination of medical records revealing much about their individual symptoms. While most sufferers reported extensive amnesia for much of their personal history, others had one or more shorter memory “gaps” involving specific events or episodes.

Most cases of psychogenic amnesia included the “fugue state”. This refers to the tendency of sufferers to wander, possibly with the intention of locating people or places that may help them recover their memories.

In comparison with hospital patients presenting with “organic” amnesia following neurological injuries, those with psychogenic amnesia displayed higher rates of depression, more frequent incidences of severe family or relationship difficulties, and marked financial or employment problems. Some or all of these are the presumed triggers of their amnesic episodes.

Unlike the organic cases in which memory of recent events was most affected, most psychogenic patients demonstrated a consistently severe loss of memories across all time periods. The outcome for patients was generally positive, with the majority recovering their memories within weeks or months, although some had persisting gaps in their memory at follow-up years later.

While psychogenic amnesia may arise following some type of stressful episode, it is far from a common consequence of trauma. Those experiencing a traumatic event are more likely to be troubled by intrusive memories or “flashbacks” than lack any memory of the trauma. The present review’s finding that most cases of psychogenic amnesia spontaneously recover is just as well, for little is known about how to treat the condition.

In the absence of neural correlates of psychogenic amnesia, it may be difficult to determine whether an individual’s symptoms are authentic or feigned: it is suspected that in some cases the person is malingering to avoid an unpleasant circumstance, such as legal, financial or personal problems.

Whether or not Agatha Christie’s wandering was a true case of psychogenic amnesia remains, perhaps appropriately, an unresolved mystery.

A/Prof Tim Hannan is Head of the School of Psychology at Charles Sturt University, and the Past President of the Australian Psychological Society.