Associations between sleep and cortisol responses to stress in children and adolescents: a pilot study.

A growing body of animal and human research suggests reciprocal associations between sleep and activity of the hypothalamic pituitary adrenocortical (HPA) axis. However, few studies have examined associations between sleep and stress-induced cortisol responses in children and adolescents. This pilot study examined associations among 3 sleep parameters (sleep-wake behavior problems, daytime sleepiness, sleep quantity) and cortisol responses to stress in 31 participants ages 10 to 17 (15 males, 16 females). During a "rest" session in which participants habituated to the laboratory, daytime sleepiness, sleep-wake behavior problems, and sleep quantity were assessed using a modified Sleep Habits Survey. On a separate day, participants completed a laboratory stress session involving 3 performance stressors. Salivary cortisol was collected during baseline, stress, and recovery periods. Significant associations between participant reported sleep-wake behavior problems and cortisol reactivity were found, with greater sleep-wake behavior problems associated with decreased cortisol responses. No associations emerged between sleep quantity and cortisol responses to stress; daytime sleepiness showed a trend toward an effect on cortisol reactivity. Although preliminary, results suggest there may be important influences of sleep quality but not quantity on HPA regulation and responses to daytime stressors in children and adolescents, and further study is warranted.