Early adolescent physical activity, sleep and symptoms of depression at 16 years of age

Aim: To examine early adolescent physical activity and risk of later depressive symptoms at age 16 years in a prospective cohort study.

Methods: Participants were children and parents enrolled at birth of the child. Approximately half the children enrolled in the Auckland Birthweight Collaborative Study were small for gestational age at birth (SGA ≤10th percentile for sex and gestation) and half were appropriate for gestational age (AGA >10th percentile). Maternal demographic data were collected at birth, and children were followed through to age 16 years. Depression at 16 was assessed using the Center for Epidemiological Studies Depression Scale for Children. Accelerometer measures of physical activity and sleep were measured at 11 years of age.

Results: Moderate to severe depression was present in 15.6% of the 467 16-year-olds. Objectively measured physical activity and sleep at 11 years were not significantly associated with depressive symptoms at 16 years of age.

Conclusion: Prospectively collected objective measures of physical activity levels and sleep were not predictive of depressive symptoms later in adolescence in a healthy community cohort. While interventions to promote increased physical activity and sleep in adolescents who are depressed may be effective, physical activity and sleep in the general population of adolescents does not protect against future depression.