Later chronotype linked to small increases in adolescent externalizing symptoms and psychotic-like experiences

Researchers examined whether sleep–wake timing preferences during early adolescence influence subsequent mental health using the Adolescent Brain Cognitive Development (ABCD) study. The cohort included 7,489 adolescents aged 9–10 at baseline and 13–14 at the fifth assessment. Chronotype was measured using the youth-reported Munich Chronotype Questionnaire at ages 11–12 and 12–13. Marginal structural models with machine learning-based weight estimation were used to estimate causal effects on parent-reported internalizing and externalizing symptoms (n = 2,668) and youth-reported psychotic-like experiences (n = 2,698).

Chronotype at ages 11–12 showed no effect on any assessed outcome. Later chronotype at ages 12–13 was associated with slightly greater externalizing symptoms (b = 0.29; p = 0.04) and more psychotic-like experiences (b = 0.05; p = 0.02) at ages 13–14. There was no association with internalizing symptoms; post hoc analyses also found no relationship with anxiety or depression symptoms in either sex.

The findings suggest that relationships between chronotype and mental health may differ by developmental stage and symptom dimension. Although the models were designed to estimate causal effects, the observational design does not establish causation. The reported effects were small, and their clinical importance cannot be determined from the abstract alone. The study does not establish that changing sleep timing improves adolescent mental health.