Functional consequences of inadequate sleep in adolescents: A systematic review

Summary

During adolescence, changes in sleep patterns due to biological and environmental factors are well documented. Later bedtimes and inadequate sleep, i.e., short and disrupted sleep patterns, insomnia and daytime sleepiness, have become increasingly common. Accumulating evidence suggests that sleep plays a crucial role in healthy adolescent development. This review systematically explores descriptive evidence, based on prospective and cross sectional investigations, indicating that inadequate sleep is associated with negative outcomes in several areas of health and functioning, including somatic and psychosocial health, school performance and risk taking behavior. Findings highlight the need for longitudinal investigations aimed at establishing the underpinnings of these associations and for developing and implementing interventions designed to achieve healthier and more balanced sleep patterns in the adolescent population.

Introduction

In the past decade, there has been an increasing interest in the investigation of sleep in adolescence.*1, 2, 3, 4 Growing evidence suggests that sleep plays a crucial role in healthy adolescent development, particularly in the regulation of important daily functions such as behavior, emotion and attention.*1, 5, 6, 7, 8, 9, 10 The main lines of evidence are obtained from sleep restriction protocols as well as descriptive studies and survey data, in which associations between sleep loss and various functional and behavioral outcomes are explored.

Investigations examining the effects of experimentally induced sleep restriction in adolescents have demonstrated declines in some neurocognitive functions.*1, 6, 7, 11, 12 In a review of the evidence, sleepiness was consistently demonstrated in most case-control sleep restriction protocols. However, evidence for cognitive deficits as a function of sleep restriction, was found in tasks of complex cognitive functions such as verbal fluency and creativity, computational speed and abstract problem solving, but not in low complexity tasks such as verbal memory, auditory attention, visual sustained attention, psychomotor speed and computational accuracy.⁷ Furthermore, it has been hypothesized that whereas single tasks may be resistant to the effects of sleep deprivation, the performance of two different tasks simultaneously, such as cognitive and emotional tasks, may be particularly sensitive to the effects of sleep loss.¹ Dahl and Lewin have suggested that such dual or multi-tasking may well represent the challenges typically encountered in adolescents' daily lives.¹

This hypothesis may explain why more consistent relationships have been reported between sleep loss and more global measures of functioning and behavior. Experimental studies have demonstrated increased academic difficulties and attention problems following sleep restriction, based on teacher ratings blind to experimental condition,¹³ as well as greater problems with behavioral regulation such as impulse control, emotional regulation and behavioral flexibility.⁵

Despite the potentially serious implications of inadequate sleep on the development and well being of young individuals, to date, the consequences of sleep patterns and disturbances on daytime functioning and health issues in the adolescent population remains a relatively understudied and unappreciated area of investigation.⁴ Few descriptive reviews, based primarily on experimental findings (i.e., sleep restriction protocols), have previously been published.7, 10, 14 However, a systematic review of descriptive studies based in naturalistic settings on sleep, health and functioning in the healthy adolescent population is lacking. The aim of this study was to systematically review the associations between inadequate sleep (i.e., sleep loss, disturbed sleep patterns and insomnia), and impairments in various measures of health (i.e., somatic and psychosocial) and daytime functioning (i.e., school performance and risk behaviors), in the normative healthy adolescent population in a naturalistic setting.