Association between sleep disorder and anhedonia in adolescence with major depressive disorder: the mediating effect of stress

Major depressive disorder (MDD) is a highly prevalent mental disorder with devastating consequences that often first manifest during adolescence. Anhedonia has emerged as one of the most promising symptoms of adolescent MDD, which means a longer time to remission， fewer depression-free days, and also increased risk of suicide ideas or actions. Research has shown that at least two-thirds of depressed adolescents have significant sleep-onset or sleep-maintenance problems. However, the association between sleep disorder and anhedonia, and the potential mediators are less understood. This is a cross-sectional study that includes 200 adolescents suffered from MDD between the ages of 12-17. We use Spearman's test to explore the relationship among main variables. To evaluate the mediating effects of stress, we applied regression models and used bootstrap method to validate the significance of effects. Significant correlation exists among sleep disorder, stress, and anhedonia (P