Sleep characteristics across the lifespan in 1.1 million people from the Netherlands, United Kingdom and United States: a systematic review and meta-analysis.

We aimed to obtain reliable reference charts for sleep duration, estimate the prevalence of sleep complaints across the lifespan and identify risk indicators of poor sleep. Studies were identified through systematic literature search in Embase, Medline and Web of Science (9 August 2019) and through personal contacts. Eligible studies had to be published between 2000 and 2017 with data on sleep assessed with questionnaires including ≥100 participants from the general population. We assembled individual participant data from 200,358 people (aged 1-100 years, 55% female) from 36 studies from the Netherlands, 471,759 people (40-69 years, 55.5% female) from the United Kingdom and 409,617 people (≥18 years, 55.8% female) from the United States. One in four people slept less than age-specific recommendations, but only 5.8% slept outside of the 'acceptable' sleep duration. Among teenagers, 51.5% reported total sleep times (TST) of less than the recommended 8-10 h and 18% report daytime sleepiness. In adults (≥18 years), poor sleep quality (13.3%) and insomnia symptoms (9.6-19.4%) were more prevalent than short sleep duration (6.5% with TST < 6 h). Insomnia symptoms were most frequent in people spending ≥9 h in bed, whereas poor sleep quality was more frequent in those spending <6 h in bed. TST was similar across countries, but insomnia symptoms were 1.5-2.9 times higher in the United States. Women (≥41 years) reported sleeping shorter times or slightly less efficiently than men, whereas with actigraphy they were estimated to sleep longer and more efficiently than man. This study provides age- and sex-specific population reference charts for sleep duration and efficiency which can help guide personalized advice on sleep length and preventive practices.

A pilot cluster-randomised study to increase sleep duration by decreasing electronic media use at night and caffeine consumption in adolescents.

OBJECTIVE: Bedtime electronic media use and caffeine consumption are risk factors for insufficient sleep and poor sleep quality during adolescence, which are in turn risk factors for mental wellbeing. Our study tested the effectiveness of a brief school-based psychoeducative intervention to primarily increase sleep duration, by decreasing bedtime electronic media use and caffeine consumption. Secondary outcomes included improving sleep quality and difficulties, daytime tiredness, and mental wellbeing. METHOD: A pilot cluster-randomised controlled study was conducted involving a 25-min psychoeducative school-based intervention combined with parent information. 352 adolescents from seven schools participated (Intervention Group/IG = 192 students vs. Control Group/CG = 160 students; age: Mean = 15.09 years; SD = 1.65 years; Females = 163). The intervention included information on the importance of sleep and good sleep hygiene habits, particularly emphasizing behavioural rules of avoiding electronic media use at night and evening-time caffeine consumption. A leaflet containing the rules was also sent to parents of IG participants. Baseline and post-intervention sessions were held approximately four weeks apart. RESULTS: Multilevel analyses revealed a significant but modest decrease in electronic media use for participants in the IG versus CG, but showed no effect on caffeine consumption or sleep duration. Moreover, the intervention did not impact any secondary outcome. CONCLUSIONS: Findings indicate the potential effectiveness of a short and easily administrable intervention to decrease electronic media use at night, which may be incorporated into school curricula and standardised for wider use in primary prevention. However, no further benefits of the intervention were found.

Chronic sleep reduction in adolescents-clinical cut-off scores for the Chronic Sleep Reduction Questionnaire (CSRQ).

The Chronic Sleep Reduction Questionnaire is a validated questionnaire that measures symptoms of prolonged insufficient and/or poor sleep and therefore accounts for individuals' sleep need and sleep debt. This study extends its psychometric properties by providing cut-off scores, using a matched sample of 298 healthy adolescents (15.38 ± 1.63 years, 37.9% male, mean Chronic Sleep Reduction Questionnaire score: 32.98 ± 6.51) and 298 adolescents with insomnia/delayed sleep-wake phase disorder (15.48 ± 1.62 years; 37.9% male, mean Chronic Sleep Reduction Questionnaire score: 42.59 ± 7.06). We found an area under the curve of 0.84 (95% confidence interval: 0.81-0.87). Cut-off scores for optimal sensitivity, optimal specificity and based on Youden's criterion are provided. These cut-off scores are highly relevant for use of the Chronic Sleep Reduction Questionnaire in future studies and clinical practice.

Differential effects of online insomnia treatment on executive functions in adolescents.

OBJECTIVE: To examine the effects of online Cognitive Behavior Therapy for Insomnia (CBTI) on adolescents' sleep and cognitive functioning. METHODS: 32 adolescents (13-19 years, M = 15.9, SD = 1.6) with DSM-5 insomnia disorder, were randomly assigned to a treatment group (n = 18) or a waiting list (n = 14). Treatment consisted of six guided self-help online CBTI sessions. Both groups were assessed at baseline and post-treatment. Sleep was measured with actigraphy, sleep logs, and questionnaires. Cognitive functioning was assessed with a battery of standard cognitive tests. RESULTS: After CBTI the treatment group showed significant improvements compared to the waiting list group in sleep efficiency from actigraphy and sleep logs. This finding was confirmed by improvements in other sleep variables from sleep logs, and in symptoms of chronic sleep reduction and insomnia. Most participants from the treatment group improved to sub clinical levels of insomnia. Cognitive functioning of the treatment group showed more improvement compared to the waiting list in visuospatial processing, selective attention and phonological working memory, and a trend of improvement in response inhibition and set shifting, letter fluency and sustained attention, but not in declarative memory, visuospatial working memory, category fluency, and general cognitive speed. Changes in sleep appeared to be related to changes in cognitive functioning. CONCLUSIONS: These results indicate that CBTI can have positive effects on cognitive functions in adolescents, with notable improvements in visuospatial processing and phonological working memory but not in visuospatial working memory.

Adolescents' electronic media use at night, sleep disturbance, and depressive symptoms in the smartphone age.

Adolescence is a time of increasing vulnerability for poor mental health, including depression. Sleep disturbance is an important risk factor for the development of depression during adolescence. Excessive electronic media use at night is a risk factor for both adolescents' sleep disturbance and depression. To better understand the interplay between sleep, depressive symptoms, and electronic media use at night, this study examined changes in adolescents' electronic media use at night and sleep associated with smartphone ownership. Also examined was whether sleep disturbance mediated the relationship between electronic media use at night and depressive symptoms. 362 adolescents (12-17 year olds, M = 14.8, SD = 1.3; 44.8% female) were included and completed questionnaires assessing sleep disturbance (short sleep duration and sleep difficulties) and depressive symptoms. Further, participants reported on their electronic media use in bed before sleep such as frequency of watching TV or movies, playing video games, talking or text messaging on the mobile phone, and spending time online. Smartphone ownership was related to more electronic media use in bed before sleep, particularly calling/sending messages and spending time online compared to adolescents with a conventional mobile phone. Smartphone ownership was also related to later bedtimes while it was unrelated to sleep disturbance and symptoms of depression. Sleep disturbance partially mediated the relationship between electronic media use in bed before sleep and symptoms of depression. Electronic media use was negatively related with sleep duration and positively with sleep difficulties, which in turn were related to depressive symptoms. Sleep difficulties were the more important mediator than sleep duration. The results of this study suggest that adolescents might benefit from education regarding sleep hygiene and the risks of electronic media use at night.