Sleep disturbance and its psychological significance in children with Down's syndrome.
The aims of the present research were to describe in more detail than previous
investigations the occurrence and nature of sleep problems and behaviours in children with
Down's syndrome compared with other learning disabled and non-learning disabled groups
and to investigate the psychological associations of these sleep problems.
The research has been conducted in two distinct phases. In the first phase, the prevalence
and range of sleep disorders was investigated in a group of children with Down's syndrome
(n=91)u sing parentalq uestionnaires.T he findings were comparedw ith a group of their nonlearning
disabled brothers and sisters (n=54), a group of children from the general
population (n=78) and a group of children with other forms of learning disability of various
aetiologies (n=71). Questionnairesw ere sent via schools in one county of the UK. Overall,
children with Down's syndrome and children with other forms of learning disability showed a
significantly greater number of sleep disorders than the siblings and children from the
general population. However, different patterns of sleep disorders were seen in the two
groups of children with learning disabilities. The findings indicated that the sleep problems
of children with Down's syndrome were predominantly physical in origin and were related to
disordered breathing and possibly obstructive sleep apnoea. Various significant associations
between sleep disorders and daytime behaviour problems, excessive daytime sleepiness
and maternal stress were also found.
The second phase consisted of a series of studies in which some of the issues from the first
phase were investigated. Overnight recordings were carried out on a group of local children
(n=31) including video and audio recording, oximetry and activity monitoring during sleep.
Information on the children's daytime behaviour was collected from parents and teachers
and a Continuous Performance Task assessment was performed on the children the next
day. Study 1 assessed the accuracy of parents' reports of the two main features used in the
clinical assessment of sleep related breathing disorders, namely restlessness during sleep
and snoring. Study 2 investigated associations between objective measures of restlessness,
snoring and blood oxygen saturation during sleep. Study 3 investigated associations
between these objective overnight measures and daytime psychological function to
determine the psychological significance of these measures in children with Down's
syndrome. The research carried out and the implications of the findings are discussed
together with future research possibilities.