Intraindividual variability of sleep/wake patterns in relation to child and adolescent functioning: A systematic review

Abstract

Summary Substantial research attention has been devoted to understanding the importance and impact of sleep in children and adolescents. Traditionally, this has focused on mean sleep variables (e.g., a child’s “typical” or average sleep duration), yet research increasingly suggests that intraindividual variability (IIV) of sleep/wake patterns (sometimes referred to as sleep variability or night-to-night variability) regularly occurs and may have implications for adjustment. A systematic search of five electronic databases identified 52 empirical studies published between 2000 and 2015 that examined correlates of sleep IIV in children and adolescents, with a recent increase in the publication rate of such studies. Identified studies were often atheoretical and included post hoc analyses, though IIV in select aspects of sleep does appear to be associated with increasing age/pubertal status, non-White race, physical and neurodevelopmental conditions (e.g., attention-deficit/hyperactivity disorder; autism), psychopathology symptoms (e.g., anxiety, depression, inattention), body weight, stress, aspects of cognitive functioning, and poorer sleep functioning/habits. The limited intervention work examining sleep IIV in adolescents is promising, though studies are needed using more rigorous intervention designs. Clinical sleep recommendations may not only need to address overall sleep duration and sleep habits but also the stability of sleep duration and timing. It will be important for future research examining sleep IIV in children and adolescents to use a developmental framework in advancing theory pertaining to the causes, mechanisms, moderators, and outcomes of sleep IIV in youth, and a conceptual model is proposed to help guide such efforts.

Prevalence of sleep problems and its relation to sleeping habits in toddlers

“…The effects of increased air pollution and climate change on sleep have been associated with respiratory problems in sleep [40]. The daily nap rate of the children in this study is similar to other studies [3-29-30-34-41] and is in the desired range [1][2][3][4][5][6][7][8]. We didn't pay on the number of daily naps of children, rather we checked the duration of the daily nap, because according to a systematic review, the frequency of daily naps at 2 years old was 0.4 -2.1 (on average 1.2 times) and have biological root and did not differ across different communities [1].…”

Sleep and mood during hospitalization for high‐dose chemotherapy and hematopoietic rescue in pediatric medulloblastoma

“…Although all sleep variables exhibited between‐subjects variability, sleep latency was the only variable with statistically significant intraindividual variability. Preliminary evidence suggests that depression is associated with greater future risk of variability in sleep latency, sleep latency variability is associated with shorter average sleep duration, and sleep variability has implications for health and well‐being . This suggests that both mean sleep and sleep variability warrant further examination.…”

Difficult to Bed and Difficult to Rise: Complex Interplay Among ADHD, Sleep, and Adolescence

“…Second, children with ADHD appear to have a stronger circadian evening preference (i.e., biological bent to stay up late) in comparison to their peers (Gruber et al, 2012), though this too remains to be examined in adolescents specifically when circadian preferences markedly shift for all youth (Hagenauer, Perryman, Lee, & Carskadon, 2009). Third, youth with ADHD exhibit significantly higher intraindividual variability of sleep in comparison to their peers (Becker, Sidol, Van Dyk, Epstein, & Beebe, 2016). This greater sleep variability may be attributed to environmental factors such as parental structure and routine and conflicts surrounding homework, leading to an increased frequency of "problematic nights" with delayed bedtime and sleep onset (Moreau, Rouleau, & Morin, 2014).…”