Nightmare frequency is related to a propensity for mirror behaviors

Nightmare distress as a mediator between frequent nightmares and depressive symptoms in Chinese adolescents

BACKGROUND

Frequent nightmares are related to depressive symptoms in adolescents. Little is known about pathways from frequent nightmares to depressive symptoms. This study aimed to examine the mediation effect of nightmare distress in the association between frequent nightmares and depressive symptoms in a large sample of Chinese adolescents.

METHODS

A total of 11,831 adolescents who participated in the baseline survey of Shandong Adolescent Behavior and Health Cohort were included in the analysis. A self-administered questionnaire was used to measure nightmare frequency, nightmare distress, depressive symptoms, sleep duration, insomnia, and demographic characteristics. Linear regressions and mediation analyses were performed to examine the associations between frequent nightmares, nightmare distress and depressive symptoms.

RESULTS

Of 11,831 participates, 50.9% were males and the mean age was 14.97 ± 1.45. Adolescents with frequent nightmares scored significantly higher on nightmare distress (t = 29.87, P <  0.001) and depressive symptoms (t = 20.05, P < 0.001) than those adolescents without frequent nightmares. Frequent nightmares (β = 1.04, 95% CI: 0.48-1.60) and nightmare distress (β = 0.30, 95% CI: 0.28-0.32) were associated with depressive symptoms. Mediation analyses showed that nightmare distress accounted for 63.76% of the total effects in the entire sample, 51.17% in males and 80.00% in females, respectively.

LIMITATION

No causality could be made from the cross-sectional data and possible information bias due to self-report.

CONCLUSIONS

The association between frequent nightmares and depressive symptoms appears to be substantially mediated by nightmare distress. Assessing and intervening distress associated with frequent nightmares may have important clinical implications for reducing the risk of depression in adolescents.

Nintendo Wii Fit-Based Sleepiness Testing is Not Impaired by Contagious Sleepiness

Sleep deprivation may cause accidents, and it has deteriorating effects on health. A measurement of postural steadiness by a portable and affordable Nintendo Wii Fit balance board can be used to quantify a person's alertness. At work, people are under the influence of their environment-often other people-that may affect their alertness. This work investigates whether sleep deprivation among people is "contagious," as quantified by sway measures. We measured 21 volunteers' postural steadiness while alert and sleep deprived. During the measurements, a screen placed in front of the participants showed a footage of either alert or sleep-deprived faces. We found a significant difference between the day time and night time steadiness, but found no effect resulting from watching footage of sleep-deprived people. This finding shows that a posturographic sleepiness tester quantifies physiological sleep deprivation, and is insensitive to the influence of social factors.