[The psychometric properties of the Hungarian version of the Morningness-Eveningness Questionnaire (MEQ-H): the separate factors of Morning Freshness and Circadian Rhythmicity].

Introduction: A large body of research has been accumulated concerning the relationship between circadian preferences (chronotype) and certain personality traits and psychopathological symptoms. Given that chronotype is related to clinically relevant personality traits, risk factors as well as diurnal variations in behavioural performance, the reliable measurement of circadian preferences might become an important step in daily psychiatric practice. In the present study, we examined the psychometric properties of the Hungarian adaptation of the Morningness- Eveningness Questionnaire (MEQ-H).

Methods: Based on the (online) questionnaire data of 840 healthy individuals, we examined the factor structure and the internal reliability of the questionnaire. The validity was assessed by different scales (sensory seeking, depressive symptoms and sleep complaints) that were previously shown to be associated with chronotype. Test-retest reliability was calculated from the data of 55 participants who completed the questionnaire twice (eight months apart).

Results: We identified two strongly correlated but separate factors, that we called Morning freshness and Circadian rhythm. According to our results, the questionnaire is a reliable instrument in order to measure individual differences in these factors, however, to increase the reliability of the scale as well as in light of practical considerations, the use of a shortened 13-itemed version might be reasonable. The two factors of the MEQ-H showed the expected associations with the examined constructs, however, the independent predictors of Morning freshness were age, gender, depressive symptoms and sleep complaints (insomniac symptoms and morning misalignment), while the independent predictors of Circadian rhythm were age, gender, depressive symptoms, circadian misalignment and sensory seeking.

Conclusion: The MEQ-H fulfils the methodological requirements of reliability and validity testing, and proved to be an adequate instrument in order to measure circadian preferences: an important factor that could be included in experimental or clinical investigations.