Evidence Hub

Association between salivary melatonin levels, sleep habits, and academic achievement in children: a pilot cross-sectional study

M. Matsui, K. Ishii, Koya Suzuki, K. Togashi

Biological rhythm research, 2026

63 participants

Abstract

ABSTRACT Sleep is crucial for brain development in children and melatonin is the main sleep-inducing hormone. However, the relationship between melatonin and academic achievement in children is not well understood. This study aimed to examine the associations between salivary melatonin levels, sleep habits, and academic achievement in elementary school children. The study comprised 63 children (26 boys and 37 girls) aged 9–12 years. Salivary melatonin levels were measured at two time points: morning (6:30 AM) and evening (9:30 PM). Sleep duration and social jetlag were assessed using self-report questionnaires. Teachers assessed the academic achievement (ranging from 21–63 points across seven school subjects). Morning salivary melatonin levels were negatively correlated with academic achievement (β = −0.312, p = 0.018), and the morning-to-evening salivary melatonin ratio was positively correlated with academic achievement (β = 0.291, p = 0.014). No correlation between evening salivary melatonin levels and academic achievement was observed. Sleep duration and social jetlag were also associated with academic achievement (p < 0.05 for all tests). Overall, morning salivary melatonin levels, morning-to-evening salivary melatonin ratios, sleep duration, and social jetlag were independently associated with academic achievement in elementary school children.

How strong is the evidence?

Evidence Hub reads this as a cross-sectional, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause. Reported size: 63 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free