As in most areas of medicine, children cannot be viewed simply as ‘little adults’ when assessing and managing sleep-related problems. Firstly, with the exception of nightmares, children rarely complain of sleep disorders themselves. Whether it is excessive snoring or behavioural disturbances at night, it is almost invariably observations from parents that lead to clinical attention. Secondly, the expectations of parents may be inappropriate, especially in the context of infants’ sleep patterns. A further potential issue for clinicians involved with children is that sleeplessness might directly reflect the effects of domestic stress or even abuse in a small minority of cases.

With these caveats, however, it is important to stress how chronic bad quality sleep in children might well have profound adverse consequences on the developing brain, body and mind. In addition, the entire family is usually affected by a sleepless child. It is not rare for a worn, haggard parent to seek help for a child who appears ostensibly happy, active, alert and well rested.

As with adults, it is simplest to consider sleep disorders in children as reflecting either insomnia or sleeplessness; excessive or inappropriate sleepiness during the day; or abnormal activities and behaviours from sleep. As with adults, these categories are by no means necessarily mutually exclusive.

Normal patterns of nocturnal sleep in children are clearly heavily influenced by age.

Newborns sleep for up to 18 hours a day with alternating 2–3 hourly cycles of wakefulness and a form of ‘active’ sleep that most closely resembles REM sleep.

By three months of age, the sleep of most babies becomes concentrated at night with 70% sleeping through until morning. Through the first year, overall sleep requirement subsequently declines progressively such that a typical one-year old will require 13 hours.

By one year, non-REM sleep stages start to be easily identified and polysomnographic measures of sleep resemble the adult pattern. Although waking through the night remains extremely common, the important variable in practice is whether the baby quickly returns to sleep when aroused or becomes even more alert and calls out. Around 10% of parents report being routinely awoken through the night by babies at one year.

Co-sleeping with infants is common in many cultures. Potential concerns over damaging or suffocating a small baby have almost certainly been exaggerated in the past. Increasingly, in industrialised populations, it is typical for parents to sleep in separate bedrooms away from young children, predominantly to avoid the absolute need for a parent to be present at any sleep–wake transition. The appropriateness of this strategy is debated, since many parents become excessively attentive to their child when the sleeping environments are separated. Furthermore, the use of intercom units potentially fuels unnecessary parental arousal.

Afternoon scheduled naps are routine at 18 months but usually decline over the subsequent three or four years such that most five- year-olds will be continually awake through the day, typically requiring around 11 hours of sleep. Problems with sleep timing most often arise when social and educational demands are juxtaposed with sleep demands.

A systematic approach and detailed history, perhaps aided by a questionnaire, is usually helpful in identifying sleep patterns and potentially bad habits or routines. The principles of sleep hygiene in childhood are outlined in Box 8.1.

Behavioural or conditioned factors are far commoner than any formal sleep disorder and will usually respond to a disciplined behavioural approach. In young children, the process of sleep onset needs to be ‘learnt’. Establishing calming bedtime rituals or sleep onset associations is crucial, certainly in the pre-school years. Prolonged nocturnal awakenings requiring the input of a parent to restore sleep are the usual main concern. Strict protocols and adherence to programmes designed to gradually establish sleep onset associations through the night are generally successful, effectively ‘extinguishing’ sleep disruptive behaviours. Positively rewarding ‘good’ nights is also advocated by some.

A common situation arises when babies are given excessive nocturnal fluids overnight such that maladaptive behaviours and bladder distension may fuel the fragmented sleep further. Gradual discontinuation of nocturnal fluids over two weeks is usually effective.

Occasionally, unsuspected medical conditions may cause insomnia secondarily. These include nocturnal asthma, cow’s milk allergy, otitis media or other painful disorders. Furthermore, the majority of neurological syndromes affecting young children will have adverse consequences for the sleep–wake cycle. This may require specialist advice regarding pharmacological treatments to aid sleep.

Children diagnosed with attention deficit hyperactivity disorder (ADHD) appear to have disproportionally disrupted sleep. Indeed, some propose that the sleep disruption in these children is the primary problem, fuelling daytime inattention and behavioural abnormalities as secondary features. In particular, as a result of poor quality sleep, children with ADHD might experience unrecognised so-called ‘microsleeps’. Any sleep subsequently accumulated during the day will reduce the sleep drive at night, reinforcing the poor sleep–wake schedule. Although unproven, this speculative interpretation might explain the paradoxical success of stimulant therapy in ADHD. These drugs may eliminate daytime microsleeps, thereby improving both the deficits in attention and the integrity of the sleep–wake cycle.

A common scenario in middle childhood and early adolescence relates to inadequate limit setting, such that a child physiologically prepared for sleep simply refuses to stay in the bedroom. The ensuing struggle with parents may escalate, most often terminating with a parent acceding to the child’s wishes and reinforcing the unwanted behaviour. Persistence and consistency with a bedroom ritual, perhaps enhanced by closing a door or gate to the bedroom, rather than punishment or expressions of anger are central to successful behavioural modification in this situation. Social or environmental factors, however, such as sharing a room with a sibling may complicate the issue of limit setting.

A significant proportion of adolescents might be considered ‘night owls’ in that they prefer to stay up late and extend their sleep period to mid-morning or later. Although behavioural or psychosocial factors may clearly fuel this tendency, it is increasingly acknowledged that the typical circadian rhythm of a teenager is delayed compared to adults such that they are, in a sense, ‘programmed’ to sleep and arise later.

A small minority of subjects with this tendency fulfil the criteria for delayed sleep phase syndrome (DSPS), in which the inability to arise at a conventional hour is so impaired as to cause major problems with schooling. Other than the timing, the sleep of these individuals is normal and the problem often resolves at weekends or when an early schedule is unnecessary. It is important to recognise that DSPS reflects a true disorder of circadian timing and not to dismiss the problem simply as reflecting bad habits or indiscipline. Treatments attempting to advance the clock mechanism are often justified although the evidence base is poor. Low dose melatonin (0.5 mg) taken at 9:00 p.m. may help to facilitate sleep onset around 11:00 p.m. whereas bright light or phototherapy immediately on waking, ideally around 8:00 a.m., may enhance morning arousal.

Benign noisy nocturnal breathing is frequently observed in young children and should be distinguished from potentially serious conditions such as obstructive sleep apnoea (OSA) or other breathing-related disorders.

Approximately 10% of five-year-olds will snore most nights without evidence for airway obstruction or sleep fragmentation (primary snoring). However, depending on precise definitions, between 1 and 2% of children will exhibit pauses in their breathing pattern, so-called hypopnoeas or apnoeas, at least five times an hour. Aside from the adverse consequences for sleep quality, secondary effects such as school failure or growth retardation can be profound.

Parents will report a variety of symptoms in children with OSA (Box 8.2). Most describe loud snoring and frequent mouth breathing at night with restlessness and enuresis affecting around 50%. Difficult daytime behaviour is also observed in 50%, with developmental delay in 20%. Overnight, children will often adopt an unusual sleeping posture with their neck hyperextended. Unlike with adults, frank daytime sleepiness is relatively rare in childhood OSA. However, in common with the adult population, increasing evidence suggests a strong correlation between the severity of sleep apnoea and hypertension, particularly systolic blood pressure.