Adolescents often sleep less than recommended and have substantially different sleep patterns between weekdays and weekends. Their mismatch in sleep timing between school and free days, known as social jet lag, has been linked to adverse physical, cognitive, and mental health outcomes, though the mechanisms have been poorly understood. In a first of its kind study, published in the journal SLEEP, researchers from Boston Children's Hospital and Johns Hopkins All Children's Hospital have found that social jetlag has widespread negative effects on fundamental aspects of the developing brain's function and structure, impacting areas of the brain that support processes such as emotional regulation and social function.
In a study of over 3,500 adolescents from the Adolescent Brain Cognitive Development cohort, the team found that over 35% of youth had social jet lag of two or more hours. Boys, Hispanic and Black non-Hispanic youth, and/or those at later stages of puberty had longer social jet lag, which was also associated with higher BMI.
Those with longer social jet lag had weaker connections between the thalamus and the rest of the brain. The thalamus plays a critical role in supporting sensory processing and emotion regulation, as well as sleep, consciousness, and mental health. Longer social jet lag was also associated with weaker connections in the salience and dorsal attention networks which support attention, as well as reward and emotion processing.
Adolescents with longer social jet lag also had lower thickness and/or volume of structures overlapping with networks supporting emotional and reward processing and social function. Longer social jet lag was also involved with lower communication and information transfer between regions supporting social function and emotion regulation.
"These findings suggest that social jet lag may have extensive detrimental effects on the adolescent brain," said Caterina Stamoulis, PhD, the principal investigator of the Computational Neuroscience Laboratory at Boston Children's Hospital, and senior author of the study. "Given the vulnerability of the brain during this sensitive period, social jet lag may have important negative implications for both mental health and cognitive function. With nearly half of adolescents experiencing social jet lag, our results underscore the importance of establishing a consistent sleep routine for adolescents to promote healthy brain development."
This study was supported by the National Science Foundation's Developmental Sciences (DS) and Computational Neuroscience (CRCNS) programs.
