Stress reactivity in salivary cortisol and electrocardiogram in adolescents: Investigating sleep disturbances and insomnia.

This study examined the role of sleep disturbances and insomnia in the context of stress reactivity in adolescence. One-hundred and thirty-five 11-18 year olds (Mage  = 14.2 years, SD = 1.9, 52% female) completed the Trier Social Stress Test for Children. Salivary cortisol and subjective stress ratings were collected at six time points, and heart rate as well as heart rate variability were measured pre-, during and post-stress induction. Additionally, sleep disturbances and insomnia diagnosis were assessed by a self-report questionnaire and a sleep interview. Robust mixed models investigated if adolescents with compared with adolescents without (a) sleep disturbances and (b) insomnia differ regarding cortisol, heart rate, heart rate variability and psychological stress reactivity considering gender effects. The results indicated that boys with high sleep disturbances showed higher cortisol activity compared with boys with low sleep disturbances, B = 0.88, p < 0.05. Moreover, in boys with insomnia, heart rate and alpha 1 significantly differ less than in boys without insomnia. These findings support the notion of sex differences regarding the association between poor sleep and increased activity of the hypothalamic-pituitary-adrenal axis, and a less adaptable autonomic nervous system in boys in response to an experimental social stress task.

Neuronal Oscillations Indicate Sleep-dependent Changes in the Cortical Memory Trace.

Sleep promotes the consolidation of newly acquired associative memories. Here we used neuronal oscillations in the human EEG to investigate sleep-dependent changes in the cortical memory trace. The retrieval activity for object-color associations was assessed immediately after encoding and after 3 hr of sleep or wakefulness. Sleep had beneficial effects on memory performance and led to reduced event-related theta and gamma power during the retrieval of associative memories. Furthermore, event-related alpha suppression was attenuated in the wake group for memorized and novel stimuli. There were no sleep-dependent changes in retrieval activity for missed items or items retrieved without color. Thus, the sleep-dependent reduction in theta and gamma oscillations was specific for the retrieval of associative memories. In line with theoretical accounts on sleep-dependent memory consolidation, decreased theta may indicate reduced mediotemporal activity because of a transfer of information into neocortical networks during sleep, whereas reduced parietal gamma may reflect effects of synaptic downscaling. Changes in alpha suppression in the wake group possibly index reduced attentional resources that may also contribute to a lower memory performance in this group. These findings indicate that the consolidation of associative memories during sleep is associated with profound changes in the cortical memory trace and relies on multiple neuronal processes working in concert.

Sleep Reactivity and Related Factors in Adolescence: An Increased Risk for Insomnia? A Longitudinal Assessment.

Purpose: The individual vulnerability for stress-related sleep difficulties (eg, sleep reactivity) is known as a predisposing factor of insomnia in adults, yet relatively little is known about sleep reactivity in adolescence. The study goal is to determine factors related to sleep reactivity and to investigate whether sleep reactivity and related factors predict current and new incidents of insomnia in adolescents. Patients and Methods: At baseline, 11-to-17-year-olds (N = 185, Mage = 14.3 years, SD = 1.8, 54% female) answered an age-appropriate version of the Ford Insomnia Response to Stress Test, questionnaires about sleep, stress, psychological symptoms, and resources, filled out a sleep diary and used actigraphy. Insomnia diagnoses according to ISCD-3 criteria were assessed at baseline, after 9 months and after one and a half years. Results: Adolescents with high compared to low sleep reactivity had increased pre-sleep arousal, negative sleep-related cognitions, pre-sleep mobile phone use, stress experience, stress vulnerability, internalizing and externalizing symptoms, less social resources, and a later midpoint of bedtime. High sleep reactivity increased the likelihood for currently having insomnia, but not for the development of insomnia at subsequent assessments. Conclusion: The findings suggest that high sleep reactivity is related to poor sleep health and mental health but cast doubt on sleep reactivity as a pivotal predisposing factor for the development of insomnia in adolescence.

Personal and social resources in the context of adolescent sleep.

OBJECTIVE: The existing literature has focused little on the health-promoting role of resources for sleep. Mainly risk factors have been highlighted regarding mental health in general. Moreover, for the vulnerable age group of adolescents, resources and their relation to sleep have hardly been explored. Therefore, this study aims to investigate the predictive role of personal/social resources for the likelihood of having chronic sleep problems in adolescents. METHODS AND MEASURES: A sample of n = 131 adolescents (M = 14.31 years, SD = 1.84) completed the Sleep Disturbance Scale for Children and the Questionnaire to Assess Resources for Children and Adolescents at two measurement points about 8 months apart. RESULTS: Binomial logistic regressions controlling for age and sex revealed that higher levels of personal and social resources were associated with a lower likelihood of having chronic sleep problems. Especially optimism and school integration were associated with not experiencing chronic sleep problems. CONCLUSION: For the first time, this study highlighted multiple resources and their health-promoting role in adolescent sleep. Both personal and social resources seem to be relevant for preventing adolescents from chronic sleep problems. Prevention and intervention programs for sleep disorders in teenagers should especially promote optimism and school integration.

Sleep and stress in times of the COVID-19 pandemic: The role of personal resources.

There is still little research on the association between COVID-19-related stress and insufficient sleep. As distress is assumed to be high in these times, the role of personal resources becomes more important. The current study aimed to investigate the predictive role of COVID-19-related stress, positive affect, and self-care behavior for subjective sleep quality and sleep change measures since the outbreak of COVID-19 in Germany. A sample of 991 adults (M = 34.11 years; SD = 12.99) answered questionnaires during the first lockdown period in Germany and afterward (between April 1 and June 5, 2020). A higher stress level predicted lower sleep quality and more negative changes in overall sleep and pre-sleep arousal. Higher levels of positive affect and self-care predicted higher sleep quality and more positive changes in sleep. Analyses showed a moderation of positive affect on the association between stress and change in pre-sleep arousal. The improvement in personal resources, especially positive affect, in times of high stress seems relevant to overcome sleep problems. Future research should include objective measurements of sleep and longitudinal designs to uncover causal directions of effects.