Stress, hypothalamic pituitary adrenal axis activity and autonomic nervous system function in adolescents with insomnia

Introduction: Abnormal stress responses have been linked to the etiology of insomnia. We investigated the relationship between insomnia, stress, hypothalamic-pituitary-adrenal (HPA) axis activity, and autonomic ner-vous system (ANS) function in adolescence. Methods: Forty-seven post-pubertal adolescents (16-20 years old, 28 female) with (N = 16; insomnia group) and without (N = 31; control group) DSM-5 insomnia symptoms were assessed for stress levels and stress reactivity and underwent a standardized stress protocol (Trier Social Stress Test (TSST)), after an overnight laboratory stay. Cortisol was measured upon awakening and 30-minutes later to calculate the cortisol awakening response (CAR). During the TSST, perceived stress, salivary cortisol (HPA activity), heart rate (HR) and blood pressure (BP) measures were collected. Results: Participants in the insomnia group reported more stress from school performance and work overload, with insomnia girls experiencing more stress from peer pressure and future uncertainty than control girls (p < 0.05). No group differences were detected in the CAR and pre-TSST stress levels. All participants showed sig-nificant increases in perceived stress (-19 %), HR (-33 %), systolic (-13 %), and diastolic (-15 %) BP in response to the TSST (p < 0.05). Overall HR stress response did not differ between groups, but was lower in boys with insomnia than in girls with insomnia (p < 0.05). Cortisol stress responses were inconclusive, possibly due to a masking effect of CAR, as the task was performed shortly after awakening and larger CARs were associated with blunted cortisol stress responses. Discussion: Results mostly show no group difference in physiological stress responses, although some interaction effects suggest a potential sex by insomnia interaction. Larger samples are needed to understand the physio-logical disturbances of insomnia in adolescence.

Automated summary

This study investigated the relationship between insomnia, stress, HPA axis activity, and ANS function in adolescence. The results showed that participants in the insomnia group reported higher stress levels from school performance and work overload, with insomnia girls experiencing more stress from peer pressure and future uncertainty. However, there were no group differences in physiological stress responses overall, although there was a potential sex by insomnia interaction.