Age as a moderator of the association between depressive symptoms and morningness–eveningness

Abstract Objectives We aimed to investigate the moderating effect of age on the association of morningness–eveningness with depression in subjects with a broad range of ages. The hypothesis of the current study was that there would be a relationship between depressive symptoms and eveningness, especially in young age groups. Methods Three hundred sixty-one subjects (male/female=140/221) from 19 to 79 years of age participated in the study. Subjects were separated into five age groups: (1) ≤20s ( n =70), (2) 30s ( n =85), (3) 40s ( n =97), (4) 50s ( n =54) and 5) ≥60s ( n =55). The Horne–Osteberg Morningness–Eveningness Questionnaire (MEQ) and the Center for Epidemiological Studies for Depression Scale (CES-D) were administered to all subjects. Results MEQ showed a significantly independent and negative association with CES-D ( β =−.27, P