Fig. 2

Mediation path diagram of loneliness, sleep quality, and depression. Note: *** indicates p < 0.001. Path c: The total effect of loneliness on depressive symptoms; Path a: The direct association between loneliness and sleep quality; Path b: The association between sleep quality and depressive symptoms; Path c’: The direct effect of loneliness on depressive symptoms after accounting for the mediating effect of sleep quality.