How much sleep to children need?
In 2013 we asked parents of children between the ages of 0-16 to complete a sleep survey to see whether children had difficulty getting to sleep and their ability to stay asleep during the night.
We divided the children into 3 age groups: ages babies and toddlers, primary and secondary school children.
We have received many replies and have collated the information.
At age 6-9 boys had a slight increased incidence of sleep problems but this gap has widened by the time they were aged 10-13.
For both boys and girls, the older age group found it more difficult to get to sleep.
Waking during the night was a minor problem at ages 6-9 but of those that did wake, the majority woke only once. As the children got older they were more likely to wake up more than 3 times a night than the younger age group.
Common effects of lack of sleep
The most common affects of waking for both sexes and all age groups were:
- Low energy levels
- Ability to concentrate
- Family relationships
Exposure to screens
The 10-13 age group had more access to media in their bedrooms including TVs, and computer access where they were using social media such as YouTube or equivalent and Facebook.
There is an increasing interest in the sleep patterns of both adults and children and how it affects our health in both the short and long term.
Research from Harvard Medical School has shown that energy efficient LEDs in light bulbs, computer screens, phones are harmful to the wake sleep cycle.
TVs, laptops, hand held devices are rich in blue light. This affects light sensors in the retina which are tuned to night-day cycle. Artificial light inhibits sleep-promoting neurons (brain cells) and the hormone melatonin which aid sleep, and activate neurons that boost alertness.
Dr Karrie Fitzpatrick from Northwestern University in Illinois, states: “having computer screens held close to your face exposes you to more light than watching a TV that is on the opposite side of room”. This proximity tells the brain to stay awake and resets circadian rhythm resulting in disturbed sleep.
Sleep and learning
Lack of sleep leaves pupils more emotionally volatile, potentially disruptive and physically struggling to learn.
However the good news is that loss of learning can be reversed providing the sleep deprivation has not become extreme. An average of 7-9 hours per night should be able to restore the functionality of accumulating, processing and being able to recall memories.
Research based on 900,00 pupils in primary/secondary schools in more than 50 countries found that internationally on average pupils who have more sleep achieve higher in maths science and reading.
The researchers believe that prevalence of computers and mobile phones in childrens’ bedrooms are primarily to blame for sleep deprivation resulting in this decreased ability to learn.
Sleep and health
Till Roenneberg, a psychologist from the University of Munich found that exposure to light in the evenings was exacerbated by the fact that many children get little natural light during day. It seems that children are sleeping 1.2 hours less on weeknights than a century ago. The research concluded that insufficient sleep may contribute to ADHD because children become hyperactive when they have too little sleep resulting in difficulty focussing attention.
Long term sleep deprivation contributed to an increased risk of cardiovascular disease, diabetes and possibly neuro-degenerative disease such as Alzheimers.
Derk-Jan Dijk, professor of sleep/psychology at the University of Surrey revealed lack of sleep affects activity pattern of more than 700 genes resulting in an increased risk of cardiovascular disease and obesity. He found that lack of sleep alters gene activity in human blood cells making some less active. Research in sleep disorders show the importance of sleep in memory and consolidating information. Without sleep the brain struggles to absorb and retain ideas thus linking an association between sleep and academic performance.
The Childrens’ Anxiety institute in the US state that children and teens need a lot of sleep with adolescents needing about nine to ten hours a day. Many parents don’t realize that once children approach puberty, their internal “sleep clock” resets, signaling them to go to bed later; however, that doesn’t mean they need less sleep. It just means that they may be incapable of getting to sleep at an early hour.
How do sleep habits affect stress and anxiety levels?
- Sleep Deprivation Increases Physical Symptoms of Anxiety
When children and teens are deprived of sleep, the physical symptoms associated with anxiety also intensify. Headaches, nausea, and hyperactivity are common responses in sleepy children.
Furthermore, children who lack the necessary sleep experienced a decreased degree of physical coordination.
- Sleep Disturbances Interfere with the Ability to Control Emotions
There is a direct link between sleep deprivation and depression and anxiety. Although depression may lead to excessive sleep in some individuals, studies have shown that children who are deprived of sleep are also at increased risk of depression. Sleep deprivation also makes children and teens irritable and easily frustrated, with emotions that fluctuate up and down. Children who accumulate a sleep debt are more likely to have a negative self-image than those who are well rested.
- Sleep Deprivation Leads to Poor Decision Making
When children don’t get enough sleep they often become impatient, which leads to poor decision making. Poor impulse control is also associated with lack of sleep, which often leads to acting out behaviors.
- Sleep Disturbances Lead to Sleepiness in School
There’s no doubt about it; sleepiness in school is a major problem for many children and teens alike. With the inability to focus, children are unable to perform optimally academically.
- Sleep Deprivation That Occurs on a Regular Basis May Be Sleep Anxiety
Sleep anxiety is a problem for 40 million Americans alone, and many children suffer from it as well. Also known as insomnia, your child may suffer from sleep anxiety if he or she has trouble falling asleep, wakes up frequently during the night, wakes up too early, or is fatigued after what appears to be a “good night’s sleep.” If a child regularly has sleep difficulties, sleep anxiety may be an underlying factor. The question is whether child anxiety leads to sleep anxiety or whether sleep anxiety is a contributing factor to general feelings of anxiety.
2005 study published in the Archives of General Psychiatry states that anxiety disorders emerge early in life: the median age of onset is 11, according to the study. Rates of depression spike in adolescence, too.
Prof Ronald Dahl, a leading researcher in paediatric sleep, from the University of California, Berkeley says: “We think that healthy, optimal sleep may be a buffer against developing anxiety and depression in kids.”
Regular bedtimes and cognitive development
The study, published in the Journal of Epidemiology and Community Health, examined more than 10,000 children who are taking part in the Millennium Cohort Study – a long-term study of children born in the UK between September 2000 and January 2002.
The research was drawn from regular surveys and home visits made when the children were three, five and seven to find out about family routines, including bedtimes.
When children were three, almost one in five had irregular bedtimes but the figure reduced to less than one in 10 when the children were older.
By the age of seven, more than half the children went to bed regularly between 7.30pm and 8.30pm.
They found that seven-year-old girls who had irregular bedtimes had lower scores on all three aspects of intellect assessed compared to children who went to bed at a regular time. But the effect was not found in boys.
Non-regular bedtimes at age three were associated with lower reading, maths and spatial awareness scores in both boys and girls.
Girls who had never had regular bedtimes at ages three, five and seven had significantly lower reading, maths and spatial awareness scores than girls who had had consistent bedtimes. For boys this was the case for those having non-regular bedtimes at any two ages.
But they also found that irregular bedtimes by the age of five were not associated with poorer brain power in girls or boys at the age of seven.
“Sleep has a crucial and complex role in the maintenance of health and optimal function,” the authors wrote.
“Inconsistent bedtime schedules might impact on markers of cognitive development in two ways, via disruptions to circadian rhythms and/or sleep deprivation and associated effects on brain plasticity.”
“Our findings suggest that inconsistent bedtimes, especially at very young ages and/or throughout early childhood, are linked to children’s cognitive development.
“Relations between inconsistent bedtimes and aspects of early child development may have knock-on effects for health and broader social outcomes throughout the lifecourse.
Consultant paediatrician Dr Robert Scott-Jupp, from the Royal College of Paediatrics and Child Health, said: “At first glance, this research might seem to suggest that less sleep makes children less intelligent, however, it is clearly more complicated than that……….such as family income, parents’ level of education and mental health with this research confirming a strong link between social disadvantage and late bedtimes.
“Researchers did go to great lengths to try to allow for this statistically yet still found the relationship between lack of sleep and development was apparent – and more so for girls.
“While it’s likely that social and biological brain development factors are inter-related in a complex way, in my opinion, for school children to perform their best, they should all, whatever their background, get a good night’s sleep.”
Strategies to encourage healthy sleep in kids
- Set a regular bedtime and wake time, even on weekends. Children who go to bed at the same time each night and wake up at the same time every morning sleep better and have fewer night wakings. Studies also show that consistent bedtimes encourage cognitive development with children displaying fewer behavioural problems and performing better in school.
- Make the bedroom a dark and quiet oasis for sleep. No homework in bed.
- Create a calming bedtime routine. A consistent routine (10 to 15 minutes long) – brushing teeth, changing into pyjamas and reading a book – helps children go from alert and active to a quieter state, giving them the ability to fall asleep on their own.
- For younger kids: a bath and story. For older kids: Reading or listening to mellow music. We recommend John Levine’s Alphamusic (www.silenceofmusic.com)
- Limit caffeine consumption, especially after 4 p.m. ie fizzy drinks, chocolate etc
- Ban technology (TV, web surfing, texting) in the half hour before bed. The activities are stimulating. The light from a computer can interfere with the production of the sleep-promoting hormone, melatonin. Encourage reading instead.
- Don’t send kids to bed as punishment or allow them to stay up late as a reward for good behaviour. This delivers a negative message about sleep.
- Exercise and access to fresh air and natural daylight can help improve sleep patterns.
YJ* Kelly, JAJ Kelly, A Sacker: J Epidemiol Community Health 2011; 65:Suppl 2 A39-A40 doi:10.1136/jech.2011.143586.88
John Levine at Alphamusic: www.silenceofmusic.com/