The real life inspiration for Nightmare on Elm Street was a mysterious psychological condition, linked to the Cambodian civil war. Its cause is still unknown.
In 1969, the Vietnam War escalated dramatically when American forces began operations in Cambodia.
Cambodia, Vietnam’s neighbour to the west, was officially neutral. But the country’s leader, King Norodom Sihanouk, allowed the Viet Cong to use bases along the border, and resupply through its territory.
US President Richard Nixon, newly elected and frustrated with Cambodia’s position, authorised covert action in the country. This commenced in March 1969; the Viet Cong bases were bombed by American planes, followed by incursions of ground troops.
Congress and the US public were initially unaware of the Cambodian campaign. It was only revealed after an investigation by the New York Times, the following May.
America entered Cambodia at a volatile moment.
Two years earlier, in 1967, civil war had broken out. Communist insurgents known as the ‘Khmer Rouge’, inspired by events in Vietnam, had taken up arms against the country’s ruling monarchy.
The American intervention added to the instability; shortly afterwards the monarchy was overthrown in an internal coup. In October 1970, Sihanouk was deposed and fled into exile, a pro-US government was formed, and the country proclaimed a republic.
The civil war continued throughout. The Khmer Rouge, now backed by North Vietnam, fought the Cambodian republican government, now backed by America.
The conflict escalated in the years following.
Government forces numbered around 200 000, supported by hardware and advisors from the United States and South Vietnam. The US withdrew their ground troops but continued their bombing campaign; between 1969 and 1973 more than half a million tonnes of bombs were dropped, causing an equal number of casualties.
America also employed thousands of locals as guides, translators, and drivers.
The Khmer Rouge used the US presence as a recruiting tool. From its original size of 3 000 poorly armed guerrillas, their forces swelled to 50 000, bolstered by weapons from North Vietnam.
The ground fighting was fierce.
In the areas under their control, the Khmer Rouge exacted violent reprisals against anyone suspected of aiding the opposition. These included executions, murders, and sexual assaults; people who had worked with the US were particularly targeted.
By 1975, Nixon was out of power, and America was keen to exit southeast Asia.
The American bombing campaign in Cambodia had ceased late in 1973, after which the Khmer Rouge advanced steadily. While still superior numerically, government forces offered only token resistance.
Phnom Penh, the capital, came under siege in January 1975. By April, the Khmer Rouge was in control of the city, and country.
Saigon fell the same month. The last American personnel in both countries were evacuated by helicopter, a humiliating defeat for the superpower.
Khmer Rouge leader Pol Pot now turned on his own country.
Foreign nationals, ethnic minorities, and anyone with links to the former government were rounded up, and either sent to forced labour camps, or done away with. More than 1 million people would be killed in the war’s aftermath, a genocide known to history as ‘The Killing Fields’.
Starvation and disease killed hundreds of thousands more.
The situation in Cambodia created a global crisis, as survivors fled the chaos. Large refugee camps were established in Thailand, and many of the displaced persons looked to America for asylum.
The American government responded by accepting large numbers of Cambodian refugees. Between 1975 – 85 more than 100 000 would be resettled in the US.
The refugees faced a difficult time. Most spoke little English and lacked formal education, they struggled to find employment and were socially isolated.
While these issues were not uncommon for new arrivals in America, as time passed it was discovered the Cambodians also faced another problem. Some of them began to die in their sleep.
In 1981, the Centre for Disease Control (CDC) began tracking a mysterious new ailment. A small but significant number of Cambodian refugees were dying each year while they slept, seemingly without explanation.
While the cause was mysterious, the victims were similar.
They were nearly all men (only 1 fatal case involving a woman was recorded), averaging 33 years of age. All were in good health, without any existing medical conditions. And all died during the night, somewhere between 10pm and 8am.
Autopsies of the victims revealed little.
‘They didn’t die of getting shot in the head, stabbed in the heart; they didn’t fall off the roof; they didn’t get poisoned.
We did an autopsy in each case, and we got a big zero.’
– Dr Michael McGee, Medical Examiner, Ramsey County
The only finding was that the victim’s hearts had suffered some kind of stress. The official cause of death was often listed as ‘cardiac arrythmia’, irregular heartbeat.
But how this caused healthy individuals to die suddenly in their sleep, remained unclear.
As doctors investigated, they came across an unusual illness largely unknown in America; a condition often called ‘Sudden Unexplained Nocturnal Death Syndrome’ (SUNDS).
First recorded in the Philippines in 1917, SUNDS seemed to provide a precedent. Victims were usually middle aged men, and were recorded gurgling or gasping in their sleep, before dying of heart failure.
The cause of SUNDS was also unknown.
SUNDS had been recorded in several southeast Asian countries, including Thailand, Laos, Vietnam and Cambodia; another link to the refugees. In those countries it had a colloquial name: ‘nightmare death syndrome’.
It was thought that the victims had frightened themselves to death.
Most of the Cambodian refugees belonged to an ethnic group known as the Hmong.
The Hmong religion is animist: they believe in a rich afterlife, replete with good spirits and demons, who can interact with the living. It is thought that a person can offend the spirits and be pursued by them, physically attacked, or even killed.
Among the refugees, this was often the accepted explanation for the mysterious deaths: the victims had been attacked in their sleep by a malevolent spirit.
While doctors could not accept that, what they did observe was that the refugees were under great psychological stress.
They had escaped a violent conflict, and many of them had directly witnessed atrocities. They had lost loved ones, and spent considerable time in refugee camps, where conditions were poor.
Finally they had been sent to America, where they struggled to adapt.
In combination with the Hmong beliefs, these experiences provided a possible explanation for the cases of SUNDS. Psychological stress, exacerbated by a fear of evil spirits, causing an extreme mental state that triggered heart failure.
Other researchers rejected this theory, and looked for a simpler explanation.
Some doctors suggested that the refugee’s physical health had been damaged in the war, which left them vulnerable to heart disease and other adjacent conditions. Another doctor proposed that their inadequate diet was responsible.
Between 1981 and 1987, the CDC recorded more than 100 fatal cases of SUND among the refugees.
And then, just as suddenly, the illness faded away again. Proponents of the psychological stress theory suggested this showed the refugees adjusting to life in America, and leaving their war experiences behind.
The cause of the deaths remains officially unknown.
Such an unusual medical mystery was widely reported in the media at the time. Among the people puzzling over it, was an aspiring young filmmaker.
Wes Craven was a former English and Humanities teacher, who followed his love of movies into a film career.
He got his start in the 1960s in the adult film industry, writing, editing and directing pornographic material, usually under a pseudonym. In the 70s he moved to Hollywood, and began working on low budget features.
Craven’s first two films as director were ‘The Last House on the Left’ and ‘The Hills Have Eyes’; both gritty, violent horror films that found a cult audience. Despite this initial success, he then struggled to find work.
The extreme content of his first movies made it hard to get projects off the ground. By the 1980s he had not worked for several years, and was struggling financially.
He developed a drug problem, and his first marriage failed.
During this period, Craven became fascinated by the ‘nightmare death syndrome’ cases, which he read about in the L.A. Times.
‘I’d read an article about a family who escaped the Killing Fields in Cambodia. Things were fine, and then suddenly the young son was having very disturbing nightmares.
He told his parents he was afraid that if he slept, the thing chasing him would get him, so he tried to stay awake for days at a time.
When he finally fell asleep, his parents heard screams in the middle of the night. By the time they got to him, he was dead. He died in the middle of a nightmare.’
– Wes Craven
The article gave Craven an idea: an evil entity, that stalks and kills a group of suburban teenagers through their nightmares, while they sleep.
Craven began developing his idea into a script, called ‘A Nightmare on Elm Street.’ Freddy Krueger, a demonic figure with a scarred face and knives on his fingers, would be the film’s nightmare killer.
Around the same time, Craven’s personal fortunes improved. He remarried in 1982, and was able to beat his addiction problems; development of his new project then became all consuming.
‘We were living in Venice, and Wes had a studio in the back. He’d be there in his bathrobe and a pith helmet, banging away on the computer.
And oh my god, it was a wonderful script.’
– Mimi Craven
Hollywood was less enthusiastic; when the script was finished, every major studio passed.
Then Craven met Bob Shaye, producer and founder of ‘New Line Cinema’. Shaye was unafraid of chancy material; New Line had been the first company to distribute films by John Waters and Werner Herzog, among other pioneering film makers.
They also produced genre films aimed at college audiences and young people.
New Line backed ‘Elm Street’ with a modest $1.1 million dollar budget. Craven would direct his own script, the cast of largely unknown actors featuring future star Johnny Depp.
When the film was released in 1984 it was a huge hit.
The movie grossed $24 million in its initial run, twenty times its budget, and far and away New Line’s most successful film to that point. The studio was known afterwards as, ‘the house that Freddy built.’
While Craven was not interested in making sequels, ‘Elm Street’ spawned a successful franchise. A follow up film, ‘Freddy’s Revenge’, was rushed out just a year later; other sequels came at regular intervals thereafter (Craven was tempted back in 1994, for his ‘New Nightmare’).
The films were all commercially successful, and were also popular on home rental.
Including a 2010 reboot there have been 9 ‘Elm Street’ films overall. Freddy Krueger has become one of the most iconic villains in film history, in one of the most recognisable horror series.
Other major outbreaks of SUNDS were subsequently recorded. One of the most serious occurred in Singapore between 1982 and 1990, when 230 immigrant Thai workers died from the condition.
Recent research has identified a range of factors that may trigger SUND, including nutrition, heart disease, metabolism, genetics, and other medical conditions like diabetes.
There is still no consensus on the primary cause.