Depression and Somatization May Link Night Eating Symptoms to Poor Sleep

A study of 460 preclinical medical students reports that depressive symptoms and somatization may statistically mediate the association between night eating symptoms and sleep quality. The research, published open access in Eating and Weight Disorders – Studies on Anorexia, Bulimia and Obesity, analyzed questionnaire data from 460 preclinical medical students and found that panic and generalized anxiety symptoms did not show the same mediating pattern.

Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Night Eating Questionnaire (NEQ), the Patient Health Questionnaire-9 (PHQ-9) for depressive symptoms, the Patient Health Questionnaire-15 (PHQ-15) for somatization, the Panic module (P-5), and the Generalized Anxiety Disorder-7 (GAD-7). The mean age was 19.90 ± 1.35 years. The mean PSQI score was 6.98 ± 2.66, with 30 percent of participants (n = 138) classified as having good sleep quality (PSQI ≤ 5) and 70 percent (n = 322) as having poor sleep quality (PSQI > 5). No significant differences in sociodemographic characteristics were found between the good and poor sleep quality groups (p > 0.05).

The comparison analyses showed that participants with poor sleep quality had significantly higher NEQ, PHQ-9, PHQ-15, and GAD-7 scores (p < 0.001). Correlation analyses reinforced the pattern: PSQI scores were positively correlated with NEQ (r = 0.498), PHQ-9 (r = 0.493), and PHQ-15 (r = 0.422). These coefficients indicate moderate positive associations, meaning that higher night eating symptom severity, more depressive symptoms, and more somatic complaints each tended to co-occur with poorer self-reported sleep in this sample.

The central test used statistical mediation analysis with 5,000 bootstrap resamples. In this framework, the researchers examined whether the association between night eating symptoms and sleep quality ran partly through depressive or somatization symptoms. Both pathways were statistically significant: PHQ-9 showed an indirect effect of β = 0.093 (95% CI: 0.008, 0.086) and PHQ-15 showed β = 0.079 (95% CI: 0.019, 0.063). By contrast, panic symptoms measured with P-5 and anxiety symptoms measured with GAD-7 did not significantly mediate the association (p > 0.05). The confidence intervals excluding zero support the specificity of the depressive and somatization pathways in these data, though the effect sizes are modest.

The new results suggest one plausible statistical route: elevated night eating symptoms co-occur with depressive and somatic symptoms, which in turn co-occur with poorer sleep quality. The authors conclude that addressing depressive symptoms and somatization could be critical in managing sleep disturbances in individuals with elevated night eating symptoms, while cautioning that further research is needed in more diverse populations.

Several limitations frame the findings. The sample consisted entirely of preclinical medical students, a young and academically homogeneous group, so the results may not generalize to older adults, clinical populations, or other cultures. Longitudinal and experimental studies would be needed to determine whether night eating symptoms, psychological distress, and sleep disturbance influence one another over time. Within those constraints, the study adds specific evidence that depression and somatization, rather than panic or generalized anxiety, may be the psychological factors most tightly woven into the night eating-sleep relationship in this population.

Subject of Research: Statistical mediation of the association between night eating symptoms and sleep quality by depressive and somatization symptoms in medical students

Article Title: Night eating symptoms and sleep quality: the mediating role of somatization and depressive symptoms

Article References: Gica, S., Bakay, H., Ozkan Yaman, N., Batur, B., Arslan, A., & Ak, M. (2026). Night eating symptoms and sleep quality: the mediating role of somatization and depressive symptoms. Eating and Weight Disorders – Studies on Anorexia, Bulimia and Obesity. https://doi.org/10.1007/s40519-026-01885-x

Image Credits: AI Generated

DOI: 10.1007/s40519-026-01885-x

Keywords: night eating symptoms, sleep quality, depressive symptoms, somatization, mediation analysis, medical students, PSQI, PHQ-9, PHQ-15, cross-sectional study, Night, eating