Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Quadratic effect for subjective sleep problems2 predicting (a) average Stanford Achievement Test (SAT) scores and (b) teacher-reported internalizing (trend level association). CI = confidence interval. The x-axis range is ± 1.75 SD (maximum range of the data) for sleep problems.
