Chronobiology internationalJul 17, 2025

Validating the Japanese short morningness-eveningness questionnaire using melatonin timing and sleep patterns in young adults

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Mar 25, 2026

Abstract

Significant correlations were observed between rMEQ scores and dim light melatonin onset (DLMO) in a sample of 20 young adults.

The Reduced Morningness-Eveningness Questionnaire (rMEQ) is a tool for assessing individual circadian preferences.
DLMO is used as a biological marker of circadian phase.
rMEQ scores showed stronger correlations with DLMO compared to the original Morningness-Eveningness Questionnaire (MEQ).
Correlations between rMEQ scores and subjective/objective sleep-wake habits were significant based on various assessment methods.
The findings support the validity of the Japanese rMEQ for evaluating circadian typology in young adults.

Simplified

The Reduced Morningness-Eveningness Questionnaire (rMEQ), a five-item version of the 19-item MEQ, is a practical tool for assessing circadian typology or "morningness" and "eveningness" preference. Although we previously validated the Japanese version of rMEQ with MEQ, external validation against an established standard was lacking. This study aimed to additionally validate the Japanese rMEQ in young adults by assessing the dim light melatonin onset (DLMO), a marker of circadian phase, and subjective/objective sleep-wake habits. Twenty healthy young adults (mean age: 23.0 ± 1.9 years) participated in this study and were assessed the circadian typology by rMEQ and MEQ. The sleep-wake habits were measured by sleep diary, actigraphy and the Pittsburgh Sleep Quality Index (PSQI). Salivary melatonin samples were collected to determine DLMO. Results showed significant correlations between rMEQ scores and DLMO, as well as sleep variables based on sleep diary, actigraphy and PSQI. Correlations between rMEQ scores and these variables were consistently stronger than those for MEQ. These findings highlight the validity of the Japanese rMEQ and that the rMEQ more accurately reflects circadian typology and internal circadian phases compared to MEQ, at least in Japanese young adults. The Japanese rMEQ could be a valuable tool for efficiently assessing circadian typologies in Japanese young adults.

Full Text

Full text is available at the source.

View Full Text ↗

Validating the Japanese short morningness-eveningness questionnaire using melatonin timing and sleep patterns in young adults

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief