Sleep disturbances are observed at any stage of the life. These disturbances are typically characterized by a decrease in the ability to initiate and maintain sleep, and by a reduced proportion of the deeper, more restorative sleep. Quality of life is substantially impaired in individuals suffering from those alterations.
Infant sleep normally changes over the first months of life to follow a diurnal rhythm with sleep lasting for a long unbroken period at night and, similarly, sleep states change from being equally distributed between REM (active) and NREM (quiet) sleep at birth to one third REM and two thirds NREM by 8 months of age. Any failure to successfully negotiate these changes in infancy can also have lasting effects on the sleep patterns of the child.
The most common sleep disturbances in infants and children are those related to wakefulness (i.e. either difficulties in settling at bedtime or failure to sleep through the night without interruptions). It has been estimated that these disturbances affect 15 to 35% of infants aged less than 24 months (France et al, “Infant Sleep Disturbance: Description of a problem behaviour process”, Sleep Medicine Reviews, Vol 3, No 4, pp 265-280, 1999). Infant and child sleep disturbances inevitably lead to parental sleep disturbance and stress which may result in inadequate child-parent interaction which in turn aggravates infant and child symptoms leading to a vicious circle.
Much of the literature which deals with infant sleep disturbance focuses on psychological factors such as pre- and post-natal stress and high levels of anxiety in the mother. For example, Field and co-workers studied the relationship between sleep disturbance, depression, anxiety and anger in pregnant women in the second and third trimesters of pregnancy and sleep patterns of their new-born infants. They observed that infants born to depressed mothers also suffered from sleep disturbances including less time in deep sleep and more time in indeterminate (disorganised) sleep (Field et al, “sleep disturbances in depressed pregnant women and their newborns”, Infant Behavior and Development 30 (2007) 127-133).
These and similar observations have led paediatricians when consulted by parents of infants and children about infant sleep disturbance to focus on recommending behavioural management techniques, such as establishing a consistent bedtime ritual, moving gradually bedtime to an earlier time or gradually reducing attention given on waking. These measures can be effective but are often difficult for the parents to apply.
Normal aging is accompanied by changes in the sleep quality, quantity, and architecture. Specifically, there appears to be a measurable decrease in the ability of the healthy elderly to initiate and maintain sleep, accompanied by a decrease in the proportion of the deeper, more restorative NREM sleep (Espiritu J R. Aging-related sleep changes, Clin Geriatr Med. 2008 24(1):1-14)
Acute and chronic stress, anxiety and depression typically lead to alterations in sleep patterns and insomnia at any age (Chorney D B, Detweiler M F, Morris T L, Kuhn B R, The interplay of sleep disturbance, anxiety, and depression in children, J Pediatr Psychol. 2008 33(4):339-48; LeBlanc M, Mérette C, Savard J, Ivers H, Baillargeon L, Morin C M, Incidence and risk factors of insomnia in a population-based sample. Sleep. 2009 32(8):1027-37).
Occasionally and in extreme cases, anxiolytic drugs (e.g. benzodiazepin) may be prescribed. However, the efficiency of these drugs is variable, establishment of the correct dose difficult to reach and the risk of adverse side-effects is high. In any event, there is a general reluctance to prescribe powerful medicaments of this type, specially for infants and young children.
From the foregoing, it may be seen that there remains a need for alternative methods to reduce sleep disturbances and improve sleep patterns in different phases of the life.