1.Overview

Insomnia and hypersomnia are defined in the International Classification of Sleep Disorders, 3rd Edition (ICSD-3), an international standard established by the American Academy of Sleep Medicine.

2.Features

Insomnia is characterized by persistent difficulties in initiating, maintaining, stabilizing, or achieving adequate quality of sleep despite having adequate opportunity and environment for sleep, resulting in significantly impaired daily functioning.

Hypersomnia, classified by the ICSD as a central disorder of hypersomnolence, involves severe daytime sleepiness and impairment in daily life that does not stem from nocturnal sleep or circadian rhythm problems. It may cooccur with other sleep disorders, necessitating differential diagnosis even with ongoing treatment for those conditions. Furthermore, its causes are diverse. Although narcolepsy is the primary cause, considering the prevalence rates, hypersomnia associated with psychiatric disorders and sleep deprivation syndrome are more commonly encountered forms of hypersomnia in pediatric psychosomatic medicine.

3.Definitions

Insomnia is diagnosed according to criteria established by the ICSD and broadly categorized into short-term sleep disorders, chronic sleep disorders, and other conditions. Figure 1 illustrates the diagnostic criteria for chronic sleep disorders as an example. Characteristically, it refers to a condition where, despite adequate sleep hygiene, sleep-related symptoms and resulting symptoms are present at least three times per week, and these symptoms persist chronically (for ≥3 months) or acutely. Additionally, this condition cannot be adequately explained by other sleep disorders.

Hypersomnia arises from various causes, primarily narcolepsy, as mentioned earlier. Figure 1 shows sleep deprivation syndrome as an example. Hypersomnia is classified into narcolepsy (types 1 and 2), idiopathic hypersomnia, Kleine–Levin syndrome, hypersomnia caused by physical illness, drug- or substance-related hypersomnia, hypersomnia associated with psychiatric disorders, and sleep deprivation syndrome. Long sleepers may be classified as a normal variant; however, because underlying causes may exist, careful investigation is essential.

4.Treatment and management

In general, in pediatric outpatient settings, treatment should be structured with careful consideration of underlying conditions that may affect sleep, including thyroid dysfunction, central nervous system genetic disorders (such as Niemann–Pick disease type C), physical illnesses (such as metabolic encephalopathy), and psychiatric disorders (such as depression) in conjunction with psychosocial information obtained during the medical history interview.

Oral medications may be not initiated immediately. Therefore, flexible lifestyle guidance was first provided while assessing sleep environment and hygiene. This can be achieved effectively by using sleep diaries, medical questionnaires, and surveys to understand and consider the social background, focusing on daily rhythms and family structure and habits. Although detailed questioning (as shown in Figure 2) is ideal, considering consultation time limitations, focus inquiries on the following four points when assessing sleep status:

1) Sleep quantity (total sleep time, time taken to fall asleep)
2) Sleep quality (presence of nighttime awakenings or nightmares, etc.)
3) Sleep phase (timing issues, such as reversed sleep–wake cycles, bedtime, and waking times)
4) Symptoms (daytime sleepiness, decreased concentration, headaches, etc.)

Questionnaires are also effective tools for screening sleep disorders. In Japan, the children’s sleep questionnaire and the Japanese version of the children’s sleep habits questionnaire (CSHQ-J) are have been used. The CSHQ-J can screen for sleep disorders in children aged 4–10 years using a cutoff value of 48 points (sensitivity, 0.69; specificity, 0.79). Currently (December 2023), the children’s sleep questionnaire is available for reference online.

Life guidance is extremely important; however, it may create tension for families and the child. Therefore, healthcare professionals should communicate challenges gently yet clearly, focus on the healthy aspects of children who are struggling and making efforts, and engage with the child and family in a constructive manner that respects everyone rather than adopting an authoritative stance. Psychosocial support is also vital for reducing psychological burden. In some cases, actively pursuing school collaboration, such as accommodations for daytime sleepiness, can be effective.

As lifestyle guidance forms the foundation, medication therapy is carefully considered only when improvement is not achieved and with the consent of the patient and their family. Furthermore, if psychosocial factors are assessed and mental symptoms are severe, or if psychological treatment is deemed necessary, collaboration with specialists in pediatric psychosomatic medicine or child psychiatry is crucial.

For hypersomnia, diagnosis may require more specialized tests, such as them multiple sleep latency test, polysomnography, or actigraphy. Therefore, consider seeking a referral to a specialized medical facility. We recommend inquiring at facilities employing specialists certified by the Japanese Society of Sleep Medicine.

ISHII, Ryuta
Kurume University School of Medicine

Fig 1

Fig 2