# Associations of Sleep, Screen Time, and Extracurricular Activities With Cognitive Development: A Longitudinal Study

## TL;DR

This study shows that sleep, screen time, and extracurricular activities are linked to cognitive development in adolescents, with lifestyle changes potentially supporting better brain development.

## Contribution

The study provides longitudinal evidence on how modifiable lifestyle factors influence cognitive development during adolescence.

## Key findings

- Longer sleep and less passive screen time are associated with improved cognitive scores in adolescents.
- Sex moderates the relationship between screen watching and physical activity with attention and inhibitory control.
- Females show stronger negative effects of passive screen watching on cognitive development.

## Abstract

Adolescence is a sensitive period typified by marked cognitive and neural development, during which modifiable lifestyle factors may be particularly relevant. However, longitudinal associations of modifiable lifestyle factors—including sleep, screen time, and extracurricular activities—with cognitive development over time remain to be investigated, leaving the directionality of these relationships unclear.

We used baseline and 2‐year follow‐up data (n = 7043) from the Adolescent Brain Cognitive Development (ABCD) study. Linear mixed‐effect models were employed to assess the association of modifiable lifestyle factors with the development of different cognitive functions over time. We additionally examined the moderating role of sex in these associations.

Longer sleep duration, greater time spent on nonphysical activities, and shorter duration of physical activity and screen usage—across passive watching, social media, and social engagement—were significantly associated with greater increases in cognitive scores. Sex moderated the association between passive screen watching and the duration of physical extracurricular activities with inhibitory control and attention. The negative association between passive watching and inhibitory control and attention development was stronger in females.

Our findings suggest that modifiable lifestyle factors are associated with adolescent cognitive development and point to the potential of lifestyle‐based interventions to support optimal development during this formative period.