Sleep in Williams Syndrome
Sleep has been investigated in a few research studies. In one study, parents reported that almost all of their children with Williams syndrome had sleep problems. Some of the most commonly reported problems included greater bedtime resistance, sleep anxiety, night waking and daytime sleepiness. Nevertheless, it was also found that children with Williams syndrome tend to sleep for 10 hours a night on average. This is similar to children in the typically developing population and is higher than the sleep time reported in many other developmental disorders.
Other research work has measured sleep experimentally over four days in children with Williams syndrome using actigraphy watches. These watches measure the amount and quality of sleep using an activity monitor worn on the wrist. This study reported the greatest sleep problem to be sleep latencies (time to get to sleep). The average latency time was 48 minutes for children with Williams syndrome, compared to 25 minutes for typically developing participants. Parents also reported night wakings and short sleep duration to be a problem; however this was not reflected in the watch data. This shows the difficulty of researching some of these behaviours.
There is some evidence that sleep problems may improve with increasing age in Williams syndrome, although this requires further investigation.