Sex differences in the association between insomnia and empathy in adolescents with major depressive disorder

Background This study aimed to estimate the prevalence and associated factors of insomnia in adolescents with major depressive disorder (MDD), and to examine the association between insomnia and empathy, including potential sex differences. Methods A cohort of 374 adolescents diagnosed with MDD was enrolled. Demographic information was collected via a self-report questionnaire. The Center for Epidemiological Studies Depression Scale (CES-D), the Interpersonal Reactivity Index (IRI), and the Insomnia Severity Index (ISI) were used to assess depression, empathy, and insomnia, respectively. Logistic regression analyses were used to identify the independent correlates of insomnia. Results Our study found that 35.8% of adolescents with MDD had insomnia. The rate was 37.2% in females and 32.4% in males, with no significant sex difference (χ² = 0.773, P  = 0.379). Significant differences were observed between the insomnia and non-insomnia groups in academic pressure, parental marital status, suicide attempts, CES-D score, and IRI score (particularly on the Fantasy and Personal Distress subscales) (all P  < 0.05). Logistic regression analyses showed that empathy was independently associated with insomnia in females (OR = 1.038, 95% CI: 1.009–1.068, P  < 0.05), but not in males. Finally, receiver operating characteristic (ROC) analyses indicated that the combination of academic pressure, parental marital status, CES-D score, and IRI score demonstrated high sensitivity and specificity for identifying insomnia (AUC = 0.785, 95% CI: 0.738–0.833, P  < 0.001). Conclusion Insomnia was prevalent in adolescents with MDD, and a significant association was observed between insomnia and empathy in this population, particularly among female patients. Future research should further investigate the underlying mechanisms linking empathy and insomnia, and develop targeted interventions to effectively improve sleep quality and overall mental health outcomes in this population.