The effects of medical or psychiatric diseaseson the association between morningness-eveningness and somatization

Abstract

Objective: Morningness-eveningness (M-E) has been found to be associated with various psychiatric disorders or symptoms. However, the relationship between M-E and somatization has not yet been fully investigated. This study aims to explore the relationship between M-E and somatization. Methods: A total of 171 subjects (mean age: 41.1±8.2 years; 42.7% males) were recruited from the Incheon area, Republic of Korea. All subjects were asked to complete questionnaires including the Horne and Ostberg morningness-eveningness questionnaire (MEQ), the Center for Epidemiological Studies Depression Scale (CES-D), and the Symptom Checklist Somatic from the Symptom Checklist-90-Revised (SCL-SOM). Multiple regression analysis was used to test hypotheses. Results: The MEQ and CES-D scores were predictors for the SCL-SOM score (MEQ: β=-0.185, p=0.001; CES-D: β=0.234, p<0.001). In subjects without medical diseases, both the MEQ and CES-D were predictors for the SCL-SOM score (MEQ: β=-0.179, p=0.007; CES-D: β=0.220, p<0.001). However, only the CES-D score, and not the MEQ score, was a predictor in subjects with medical diseases (CES-D: β=0.230, p=0.019). Similarly, the CES-D score was the only significant predictor in subjects with psychiatric diseases (CES-D: β=0.'7, p<0.001); both the MEQ and CES-D scores were significant predictors in subjects without psychiatric diseases (MEQ: β=-0.243, p<0.001; CES-D: β=0.203, p=0.002). Conclusion: M-E and somatization are significantly associated, independent of depression or anxiety status, indicating that somatization is independently influenced by morning-evening preference. An association between M-E and somatization is evident only in subjects without medical or psychiatric problems. © 2019 Korean Academy of Sleep Medicine.