These declines indicate that the intensity of the homeostatic or restorative processes at the beginning of sleep diminished across adolescence. We propose that this change in sleep regulation is caused by the synaptic pruning that occurs during adolescent brain maturation.

Although traumatic events are presumed to cause sleep disturbances, particularly insomnia, sleep in populations subjected to forced displacement has received little attention. The present study examined the prevalence of insomnia and associated factors in internally displaced persons (IDPs) from Abkhazia 15 years after displacement to Tbilisi. Detailed subjective information about sleep-wake habits, sleep-related and stress-related parameters were obtained from 87 IDPs categorized into good sleepers and insomniacs. The Insomnia Severity Index, Perceived Stress Scale and Beck Depression Inventory were administered. The incidence of insomnia was 41.4%. The majority of insomniacs strongly believed that war-related stress accounted for the onset of their insomnia. Stepwise regression (95% confidence interval) revealed four variables significantly associated with insomnia status: self-estimated influence of war related stress (odds ratio (OR) = 2.51), frequency of nightmares (OR = 1.6), Perceived Stress Scale score (OR = 1.14) and Beck Depression Inventory score (OR = 1.12). Insomnia in IDPs was strongly related to war-associated remembered stress. ‛Over thinking' about major stress exposure enhanced IDPs' vulnerability to insomnia. These findings have implications for the management of insomnia and associated impairment of daytime functioning in IDPs.

The extent to which sleep disorders are associated with impairment of health-related quality of life (HRQoL) is poorly described in the developing world. We investigated the prevalence and severity of various sleep disorders and their associations with HRQoL in an urban Georgian population. 395 volunteers (20–60 years) completed Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, STOP-Bang questionnaire, Insomnia Severity Index, Beck Depression Inventory-Short Form, and Short Form Health Survey (SF-12). Socio-demographic data and body mass index (BMI) were obtained. The prevalence of sleep disorders and their association with HRQoL was considerable. All SF-12 components and physical and mental component summaries (PCS, MCS) were significantly lower in poor sleepers, subjects with daytime sleepiness, apnea risk, or insomnia. Insomnia and apnea severity were also associated with lower scores on most SF-12 dimensions. The effect of insomnia severity was more pronounced on MCS, while apnea severity—on PCS. Hierarchical analyses showed that after controlling for potential confounding factors (demographics, depression, BMI), sleep quality significantly increased model’s predictive power with an R2 change (ΔR2) by 3.5% for PCS (adjusted R2 = 0.27) and by 2.9% for MCS (adjusted R2 = 0.48); for the other SF-12 components ΔR2 ranged between 1.4% and 4.6%. ESS, STOP-Bang, ISI scores, all exerted clear effects on PCS and MCS in an individual regression models. Our results confirm and extend the findings of studies from Western societies and strongly support the importance of sleep for HRQoL. Elaboration of intervention programs designed to strengthen sleep-related health care and thereof HRQoL is especially important in the developing world.

The incidence of eye movements during rapid eye movement sleep is substantially reduced in the elderly. We hypothesize that this reduction is due to degenerative (aging) rather than developmental brain changes. The correlation analysis indicates that EMD is a reasonably stable individual trait in both young and elderly adults. These results encourage normative studies of EMD over a wider age span and continued exploration of the relation of EMD to cognitive function in the elderly.