The terms ‘nightmare’ and ‘night-terror’ are often used interchangeably but they are actually very different occurrences.
Night terrors
Night terrors are a form of parasomnia, a sleep disorder that occurs when there is a partial arousal from non-REM (deep) sleep.[1]
Typically, during a night terror a child will shout or scream, thrash/flail and exhibit signs of autonomic arousal, such as increased heartrate and sweating, seeming neither fully awake nor fully asleep.
This can understandably be distressing for a parent, especially as a child may have their eyes open and look awake but be unable to ‘snap out’ of the episode, even if a parent intervenes.
As they occur during periods of non-REM sleep, night terrors are most common in the first three hours of the overnight sleep.[2]
Night terrors are much more prevalent in children than adults[3] and most children eventually grow out of them by adolescence.[4] Research conflicts as to the most likely age for their occurrence. One recent study found around 18 months old to be the peak for night terrors.[5] Other studies have found they peak in the early school years.[6]
While night terrors affect over half of children at some point,[7] in most cases, their occurrence is relatively benign and does not pose a significant problem.[8]
What contributes to night terrors?
Tips for if your child experiences night terrors
The likelihood of experiencing night terrors can be reduced by: ensuring your child has the opportunity to take enough sleep (both at night and through the day); a consistent bedtime preceded by a predictable and positive bedtime routine; and ensuring your child’s sleep environment is calm and sleep-supportive.
Sometimes though, night terrors are beyond our control and when a child experiences one, the key concern is to keep them physically safe.
During REM sleep, our muscles are paralysed.[10] This isn’t the case in non-REM sleep when night terrors occur, meaning children may thrash, kick, sit up and even get out of bed. Keep them safe by clearing bedroom floors of trip hazards and ensuring there is no open access to stairs or windows.
It is tempting to wake a child from a night – terror, but there is no need to and attempts to do so, or to comfort, may lead to more distress. Monitoring without intervening tends to be best, unless your child is at risk of hurting themselves. Night terrors can last anywhere from a few minutes through to 30-40 minutes.
Try to stay calm and remember that these are a physical event, they rarely indicate any underlying pathology, and that once the episode passes your child will settle back into quiet sleep.
If your child does wake fully during a night terror, they are likely to be groggy and irritable, having awoken from what is still quite a deep state of sleep. If this happens, calmly soothe your child back to sleep.
Night terrors are not something a child will remember on waking[11] and there is no need to discuss their occurrence – doing so can cause a child to become confused or anxious about what happened.
If your child frequently experiences night terrors at a similar time each night, gently nudging/rousing around 20 minutes before this usually happens can be an effective way to help to avoid the night terror occurring.
Nightmares
In contrast to night terrors, which occur in non-REM sleep, nightmares are much more likely to happen REM sleep, when our brain is very active.[12] As we have more REM sleep in the second half of the night, nightmares are more common after midnight.
While some studies show parents reporting bad dreams in toddlers,[13] most experts agree that nightmares as we know them are unlikely under the age of two. By ages four to six, over two thirds of children report experiencing bad dreams from time-to-time.[14]
Children are much less likely to vocalise or move when experiencing a nightmare but are likely to wake suddenly in a state of ongoing distress. What they dreamed about is likely to feel real.
Tips for helping your child if they have a nightmare
Bringing your child into the parental bed following a nightmare might help them to resettle to sleep in the short term. However, this can lead to your child being reluctant to sleep in their own room thereafter. For your child to feel safe in their own room, a more consistent approach is for them to remain in their own bed, with your support, to settle back to sleep after the nightmare.
Unlike night terrors, it can help to discuss a nightmare after the event – but only if your child wants to. Try not to trivialise or dismiss any worries your child expresses – what can seem small or silly to us can be a big deal for a still-developing brain.
Don’t collude in fears by engaging in activities such as under-the-bed monster checks. Explain in age-appropriate terms that dreams are just thoughts, that they happen to everyone sometimes, but they can’t physically hurt us.
As with all things sleep, having a consistent bedtime routine,[15] a calm sleep environment and practising good sleep hygiene, such as turning off tech for at least the last hour of the day and avoiding eating too close to bedtime, can help all children settle in a restful sleep.
For children who become anxious as to the possibility of further bad dreams, helping them to ‘park’ worries ahead of bedtime using a worry-eater or a children’s guided meditation to fall asleep to, can be useful tools.
If nightmares or night terrors persist despite you taking steps to minimise their likelihood, or if they are causing your child a significant amount of disturbance or distress, it is worth discussing matters with your GP or health visitor.
References:
1. Moreno M. A (2015) Sleep Terrors and Sleepwalking: Common Parasomnias of Childhood. JAMA Pediatrics, 169(7) p. 704.
2. Leung A. K. C, Leung A. A. M, Wong A. H. C & Hon K. L (2020) Sleep Terrors: An Updated Review. Current Pediatric Reviews, 16(3) p. 176-182.
3. Mason T. B 2nd, Pack A. I (2007) Pediatric Sleep, 30(2) p. 141-151.
4. Laberge L, Tremblay R. E, Vitaro F & Montplaisir J (2000) Development of parasomnias from childhood to early adolescence. Pediatrics, 106(1 Pt 1) p. 67-74.
5. Petit D, Pennestri H, Paquet J, Desautels A, Zadra A, Vitaro F, Tremblay R. E, Boivin M & Montplaisir J (2015) Childhood Sleepwalking and Sleep Terrors: A Longitudinal Study of Prevalence and Familial Aggregation. JAMA Pediatrics, 169(7) p. 653-658.
6. Leung A. K. C, Leung A. A. M, Wong A. H. C & Hon K. L (2020) Sleep Terrors: An Updated Review. Current Pediatric Review, 16(3) p. 176-182.
7. Ellington E (2018) It's Not a Nightmare: Understanding Sleep Terrors. Journal of Psychosocial Nursing and Mental Health Services, 1;56(8) p. 11-14.
8. Petit D, Touchette E, Tremblay R. E, Boivin M & Montplaisir J (2007) Dyssomnias and parasomnias in early childhood. Pediatrics, 119(5) p. 1016-1025.
9. Nguyen M. D, Perusse D, Paquet J, Petit D, Boivin M, Tremblay R. E & Montpaisir J (2008) Sleep Terrors in Children: A Prospective Study of Twins. Pediatrics, 122 (6) p. 1164–1167.
10. Brooks P. L & Peever J. H (2011) Triggers Cardinal Features of Rapid Eye Movement Sleep Behavior Disorder in Mice. Journal of Neuroscience, 31(19) p. 7111-7121.
11. Leung A. K. C, Leung A.A. M, Wong A. H. C & Hon K. L (2020) Sleep Terrors: An Updated Review. Current Pediatric Review, 16(3) p. 176-182.
12. Leung A. K. C, Leung A.A. M, Wong A. H. C & Hon K. L (2020) Sleep Terrors: An Updated Review. Current Pediatric Review, 16(3) p. 176-182.
13. Hawkins C, Williams T. I (1992) Nightmares, life events and behaviour problems in reschool children. Child Care Health Developments, 18 p. 117-128.
14. Simard V, Nielsen T. A, Tremblay R. E, Boivin M & Montplaisir J. Y (2008) Longitudinal study of bad dreams in preschool-aged children: prevalence, demographic correlates, risk and protective factors. Sleep, 31(1) p. 62-70.
15. Mindell J. A & Williamson A. A (2018) Benefits of a bedtime routine in young children: Sleep, development, and beyond. Sleep Medicine Reviews, 40 p. 93-108.