Study Suggests Older, Preteen Children May Not Be Getting Enough Sleep To Meet Their Daily Physical And Mental Needs

Washington - Children in the sixth-grade may suffer adverse cognitive, behavioral and emotional consequences due to an increased risk of being chronically sleep deprived, according to a new study in the May issue of Developmental Psychology, a journal published by the American Psychological Association (APA). The study of 140 Israeli elementary school children also found that family stress, parental age and parental education may all play a role in a child's sleep-wake patterns.

Study authors Avi Sadeh, Ph.D., Amiram Raviv, Ph.D., and Reut Gruber, Ph.D., of Tel Aviv University, used various methods to gauge the sleep patterns of 72 boys and 68 girls in the second, fourth and sixth grades from mostly two-parent middle-class or upper middle-class families. Each child was monitored with an actigraph, a miniaturized wristwatch-like device that the child attaches to his or her wrist during the recording period. The device enables continuous recording for prolonged periods with no interference with the child's natural sleep environment. Daily logs were used to obtain subjective information from the children, along with a questionnaire on sleep habits that the parents and children filled out independently.

Results show that sleep onset time in second grade was more than one hour earlier than that in sixth grade, although sleep quality appears to remain stable across the age range studied because no age differences were found on any of the objective sleep quality measures. However, the subjective measures indicate that the older children (sixth grade) reported increased morning drowsiness compared with the younger children. "These findings," according to the authors, "suggest the age-related significant delay in sleep onset and the shortening of sleep lead to chronic partial sleep deprivation and increased day-time sleepiness even in this age group preceding adolescents, where such a tendency has already been established."

"The significant reduction in sleep duration coupled with the significant increase in daytime sleepiness found in our study suggests that the sleep behavior of the older children may not be in accordance with their physiological needs," say the authors. These children, according to the researchers, are at increased risk of being chronically sleep deprived, which could have adverse consequences, involving the child's development.

Physiological and hormonal changes explain part of the reason for the older children delaying sleep, but psychosocial reasons that are familiar to American children are also involved, according to lead author Dr. Sadeh. "There are increased school demands, the need of children to feel more like adults by having a more active night life and the incentives like late-evening or late-night TV shows and Internet surfing," he said.

Other findings of the study suggest that younger parents are more likely to enforce an earlier bedtime, which resulted in extended sleep durations. However, the best predictors of sleep quality measures, according to the authors, were the parents' education and family stress. "Although it is not entirely clear why the children of parents with a higher education level sleep better, this finding is consistent with a recent report correlating poor sleep with lower maternal education," said the authors. They add that family stress (loss, illness, hospitalization, relocation and emotional turmoil within the family) may lead to poor sleep in children because increased stress and the anxiety associated with it are likely to activate an alarm response that triggers the activity of the adrenocortical system, which results in alertness.

Article: "Sleep Patterns and Sleep Disruptions in School-Age Children," Avi Sadeh, Amiram Raviv and Reut Gruber, Tel Aviv University; Developmental Psychology, Vol. 36, No. 3.

Full text of the article is available from the APA Public Affairs Office or at http://www.apa.org/journals/dev.html