Association Between Depressive Symptoms and Severe Vision Difficulty Among United States Adults

Background: Depression and vision impairment are major public health concerns, yet the association between depressive symptom severity and severe vision difficulty remains unclear. Methods: We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey 2013-2018. A total of 9,227 adults were included. Depressive symptoms were assessed using the Patient Health Questionnaire-9. Severe vision difficulty was defined as self-reported serious difficulty seeing or being blind. Survey-weighted logistic regression, restricted cubic spline modeling, and subgroup analyses were performed to evaluate the associations. Results: Among 9,227 participants, 632 (6.85%) reported severe vision difficulty. In the fully adjusted model, compared with participants with no depressive symptoms, the odds ratios for severe vision difficulty were 1.74 (95% CI: 1.28-2.37) for mild depressive symptoms, 2.28 (95% CI: 1.56-3.34) for moderate depressive symptoms, 4.77 (95% CI: 2.16-10.51) for moderately severe depressive symptoms, and 5.20 (95% CI: 2.87-9.44) for severe depressive symptoms (P for trend < 0.001). When analyzed continuously, each five-point increase in PHQ-9 score was associated with higher odds of severe vision difficulty (OR: 1.60, 95% CI: 1.43-1.79, P < 0.001). Restricted cubic spline modeling showed a significant overall association (P for overall association < 0.001), whereas the test for nonlinearity was not significant (P for nonlinearity = 0.560). Exploratory subgroup analyses showed no significant interaction across major demographic and clinical strata (all P for interaction > 0.05). Conclusions: Depressive symptom severity was independently and linearly associated with severe vision difficulty among adults in the United States. These findings suggest that greater depressive symptom burden may be linked to poorer visual health in the general population.