‘Exploding Head’ study reveals hopes and fears of sufferers

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New research into the mysterious phenomenon of Exploding Head Syndrome explores who experiences the condition, why they believe it happens, and how they try to prevent it.

Exploding Head Syndrome (EHS), also called episodic cranial sensory shock, is a sensory disorder characterised by the perception of a loud noise or sense of explosion in the head, usually when transitioning into or out of deep sleep.

Little is known about the exact cause of EHS and, while it is not dangerous, it can lead to fear, anxiety, and interrupted sleep.

A team of psychologists at Goldsmiths, University of London, St Mary’s College of Maryland, the University of Notre Dame and the University of Sussex analysed self-reported data on 6,686 people who answered questions on EHS as part of a survey about sleep and sleep disorders run through BBC Science Focus magazine in 2017. 

The magazine published an article on the findings today (Monday 13 July).

The study, the largest survey of EHS to date, shows that just under half of sufferers reported moderate or high levels of fear during EHS episodes. 

Previous research suggests experiencing EHS is common. The sample of people with EHS taking part in this survey was large, with 3,286 people reporting EHS episodes. Another 446 people initially reported EHS symptoms, but were excluded due to other medical conditions or excessive pain during episodes. 2,954 people surveyed said they had never experienced EHS.

While 161 people said they experienced EHS several times a week, it occurred infrequently in most people. 1,147 people had an episode several times a year, and 1,318 experienced it twice or several times in a lifetime.

44.4% reported clinically significant levels of fear during EHS episodes. 25.5% reported clinically significant levels of distress and 10% impairment as a result of episodes. This risk increased with episode frequency. 

Participants were asked if they attempted to prevent EHS episodes and could list up to four prevention strategies and rate their perceived effectiveness from 0-100%.

The prevention attempts listed first, and their perceived effectiveness were: 

Increasing the use of alcohol (which was given an 81% perceived effectiveness rating by those who listed it) or medication (70%) before sleeping, avoiding sleeping on the back (80%) or sleeping on an unspecified side (64%), going to bed earlier (50%), getting more sleep (52%), using mindfulness (63%) or relaxation (49%) techniques, trying to stay awake (40%), getting up (92%), trying to wake up (81%), and adjusting sleep environment (40%). 

When asked what they think causes EHS, 60% of sufferers said that they believe it is due to “something in the brain”. “Stress” was frequently endorsed (by 1,136 people or nearly 35%), while 235 people (7%) think EHS might be a side effect of their medication. 92 people (3%) theorised it could be “something supernatural” while 75 people (2%) think “electronic equipment” might cause the condition. Participants could endorse multiple causes. 

The average length of sleep for all survey participants was six hours 42 minutes per night. People with EHS reported that their sleep duration was on average about six minutes shorter than those without, and it took 30 minutes longer for them to transition from full wakefulness to sleep.

Study co-author Professor Chris French, Head of the Anomalistic Psychology Research Unit at Goldsmiths, said: "Previous research has suggested that a substantial proportion of the population worldwide will experience EHS at least once in their lives. So although only a small percentage of our sample opted for unconventional explanations such as 'something supernatural' or the effects of 'electronic equipment', this phenomenon is probably explained in such terms by many millions of people around the world."

Study co-author Dr Brian Sharpless said: “Although they can be dramatic and scary, EHS episodes are relatively harmless. However, a small percentage of people have them so regularly that normal sleep patterns are disrupted and others worry that EHS episodes may be a sign that something is seriously wrong with their mental or physical health. Our hope is that future studies will help to identify effective treatment options for the minority of people who suffer from severe EHS.” 

Exploding Head Syndrome: largest ever study of mysterious condition was published by BBC Focus on Tuesday 14 July 2020

Exploding Head Syndrome: Clinical Features, Theories about Etiology, and Prevention Strategies in a Large International Sample by Brian Sharpless (St Mary’s College of Maryland), Daniel Denis (University of Notre Dame, Indiana), Rotem Perach (University of Sussex), Christopher French and Alice Gregory (both Goldsmiths, University of London) is published in the journal Sleep Medicine: https://doi.org/10.1016/j.sleep.2020.05.043