Associations of sleep disturbance with somatic and cognitive-affective depressive symptom dimensions in adolescents: The moderating role of body mass index.

OBJECTIVES

Depressive symptoms are common in adolescents and can be divided into cognitive-affective and somatic dimensions. Sleep disturbance has been consistently associated with depressive symptoms. However, few studies have examined whether its associations differ across symptom dimensions or whether body mass index moderates these links. This study aimed to investigate the longitudinal associations between sleep disturbance and subsequent depressive symptom dimensions and to explore the moderating effect of body mass index.

METHODS

A total of 9726 adolescents who completed standardized questionnaires and physical examinations at both baseline and follow-up were included. Sleep disturbance, body mass index, and covariates were assessed at baseline. Depressive symptoms were measured at baseline and follow-up using the 9-item Patient Health Questionnaire (PHQ-9) and categorized into cognitive-affective and somatic domains. Mixed linear regression models, interaction analyses, and subgroup analyses were used to examine the associations.

RESULTS

After adjusting for covariates and baseline depressive symptoms, adolescents with sleep disturbance had significantly higher scores for overall (β = 1.51; 95% CI, 1.28-1.75), cognitive-affective (β = 0.53; 95% CI, 0.42-0.64), and somatic (β = 0.99; 95% CI, 0.85-1.13) depressive symptoms, compared with those without sleep disturbance. A modest positive interaction between sleep disturbance and body mass index was observed for somatic symptoms (β = 0.01; 95% CI, 0.001-0.01), but not for cognitive-affective or overall depressive symptoms. Stratified analyses showed a slightly higher β-estimate among adolescents with obesity than those without (β = 1.06; 95% CI, 0.57-1.56).

CONCLUSIONS

These findings highlight the relevance of sleep disturbance and body mass index in relation to dimension-specific depressive symptoms among adolescents.