Sleep disorders in children
Mindell defines pediatric insomnia as "a repeated difficulty with sleep initiation, duration, consolidation, or quality that occurs despite age-appropriate time and opportunity for sleep and results in daytime functional impairment for the child and/or family”.
Research estimates that between 1 and 6% of children suffer from pediatric insomnia, more if children with developmental or chronic medical/psychiatric conditions are considered. In a 2006 Sleep in America poll, more than 50% of children and adolescents had difficulty falling or staying asleep during the week.
Other research show that a common type of pedriatric insomnia is sleep-onset association. This is a type of behavioural insomnia wherein children are unable to fall asleep without a certain association such as:
- Undergoing a certain activity (e.g., watching TV)
- Being in a certain place (e.g., parents' bed)
- Holding a certain object (e.g., a favourite stuffed toy)
This form of insomnia occurs in around 10-30% of children, mostly in infants and toddlers, and is rare over the age of 4.
Circadian sleep disorders
Delayed Sleep Phase Disorder (DSPD)
This is a sleep rhythm problem wherein individuals tend to fall asleep very late and have difficulty waking in the morning. It occurs mostly in adolescents and young adults, in about 0.13-3% of the population.Chronic insomnia is often associated with DPSD. It is associated with psychiatric and personality problems, and has a strong genetic component.
Advanced Sleep Phase Disorder (ASPD)
Individuals tend to fall asleep very early in the evening and wake up very early in the morning. This disorder is very rare in children and is generally seen in middle-age.
Individuals seem to have no stable circadian rhythm (unlike DSPD or ASPD where the rhythm is simply shifted forwards or backwards), is common in blind individuals including children. It can occur in sighted individuals who are being treated for DSPD or who have been isolated from external time cues such as light.
Sleep-related movement disorders
Restless Legs Syndrome (RLS)
Previously thought to affect only adults, this disorder wherein individuals feel compelled to move their limbs (typically their legs) to improve a feeling of discomfort is now thought to affect between 1-2% of children and adolescents. It’s more common in females and has a genetic component. Children with ADHD are at particular risk for this disorder.
Periodic Limb Movement Disorder (PLMD)
This disorder is characterized by repeated limb movement during sleep, especially extension of the legs. It is worse while resting or sleeping. It is related to RLS but lacks the feeling of discomfort characteristic of that disorder.
This is a broad category of sleep problems, the third most common in children after insomnia and night awakenings. It includes nightmares, sleepwalking and sleeptalking, nocturnal bruxism (grinding of the teeth), nocturnal enuresis (bedwetting), and some movement disorders. They are primarily linked to genetic and developmental factors rather than psychiatric factors (which is the case in adults).
Sleep-related breathing disorders
Obstructive Sleep Apnea Syndrome (OSAS)
OSAS is a common sleep disorder in young children, affecting between 2-3% of the population. It is characterized by repeated episodes of respiratory obstruction leading to hypoxia (low oxygen levels), hypercapnia (high carbon-dioxide levels), or respiratory arousal where cessation in breathing wakes the child up. OSAS can lead to health problems including slowed growth, neurobehavioural problems, and cardiovascular problems. Risk factors include: African descent, obesity, sinus problems and allergies, a family history of OSAS, and being born premature.
Upper Airway Resistance Syndrome (UARS).
UARS is brief but recurring respiratory arousals similar to those in OSAS but without sleep apnea or hypopnea. It is difficult to diagnose but has been associated with neurobehavioural problems such as learning disabilities and ADHD.
Persistent Primary Snoring (PPS)
Habitual snoring in children is often associated with respiratory problems but not with arousals such as in OSAS or UARS. It occurs in up to 27% of children, of whom some 2-3% have clinical levels of OSAS.
Narcolepsy is a rare rapid-eye movement sleep hypersomnia (excessive sleepiness disorder) whose symptoms include sudden and unexpected sleep, hypnagogic hallucinations (which occur on the border of sleep and wake), cataplexy (sudden loss of muscle tone), and sleep paralysis (wherein individuals find themselves unable to move for a short time after waking). It is rare in children and usually starts occurring during adolescence. Two major types of narcolepsy exist, with and without cataplexy.
This disorder is characterized by periodic excess sleepiness along with increased appetite, hypersexuality, and behavioural problems. It is rare and starts in early adolescence, with females having a later onset and lower occurrence than males.
Behaviourally induced insufficient sleep syndrome
This syndrome occurs when someone continually does not get enough sleep at night, which prevents them from feeling well-rested and alert throughout the day. The lack of sleep results from personal choices one makes (i.e., putting their social life, work obligations, schoolwork, etc. ahead of getting enough sleep). They are normally unaware, however, that they need more sleep than they are getting, and would be able to sleep well if given the chance. There is no other medical explanation for the fatigue and poor concentration experienced by these individuals. This disorder can affect people of all ages and genders, though it occurs most frequently in adolescents.
Psychiatric disorders and sleep
Sleep problems are frequently reported in clinical practice for children with ADHD. However there has been little research done on the connection between sleep and neurobehavioural function in ADHD. Some findings suggest that children with ADHD have unstable sleep patterns, a harder time falling asleep, and more daytime sleepiness than children without ADHD.
The hyperactive and inattention aspects of ADHD have also been linked to a number of sleep disorders:
- Restless legs syndrome possibly due to a common dysfunction in dopaminergic systems
- Sleep-disordered breathing, which disrupts daily recovery of executive functions in the pre-frontal cortex
Children with anxiety or depressive disorders have high rates of nightmares and restless sleep. More specifically, childhood depression is associated with increased insomnia, early morning awakenings, and problems with sleep onset. Similar problems have commonly been reported in children with autism spectrum disorder (ASD).
In general, behavioural problems are associated with wrong sleep duration and latency (time at which one falls asleep), and psychiatric disorders are associated with restless sleep.
This content was developped by Reut Gruber, PhD, thanks to the support of Manulife.