Shorter weeknight sleep duration mediates the relationship between earlier adrenarche and depressed mood in adolescents.

BACKGROUND

Shorter weeknight sleep duration has not been assessed as a mediating mechanism linking earlier pubertal timing to a greater burden of adolescent depression symptoms.

METHODS

Among 1138 participants (48.6 % female) from Project Viva, a pre-birth longitudinal cohort, we examined relationships among pubertal timing measures, actigraphy-captured and self-reported weeknight sleep duration across mid-adolescence, and depression symptoms in late adolescence. We assessed pubertal timing using age at peak height velocity, self-reported adrenarche (Tanner pubic hair stage) and parent-reported Pubertal Development Scale scores in early adolescence. Relationships were adjusted for age, sex, mid-childhood BMI, and socioeconomic status; effect modification by sex was considered throughout. The mediational g-formula estimated the indirect effect of pubertal timing on depression symptoms via weeknight sleep duration.

RESULTS

All measures of earlier pubertal timing predicted shorter actigraphy-measured sleep duration; self-reported adrenarche predicted self-reported sleep duration and depression symptoms. No effect modification by sex was found. In both sexes, a 1-stage advance in adrenarche was associated with less (-0.14 h (95 % CI -0.23,-0.05)) self-reported sleep on weeknights across the mid-adolescent years. The relationship between earlier adrenarche and depression symptoms was mediated by self-reported weeknight sleep duration - a decrease in sleep duration in mid-adolescent years attributable to a 1-stage advance in adrenarche increased depression symptoms by 0.22 points (95 % CI 0.08,0.40).

LIMITATIONS

The geographic specificity and attrition in Project Viva limit the generalizability of our findings.

CONCLUSIONS

Maintaining adequate weeknight sleep across adolescent years may mitigate the impact of earlier adrenarche on depressed mood in late adolescence.