Association of optic neuritis with incident depressive disorder risk in a Korean nationwide cohort

Studies have highlighted complex bidirectional relationships between autoimmune diseases and depressive disorders. Given that early mental health interventions have substantial public health implications, this study investigated association between optic neuritis, an autoimmune inflammatory disorder of the optic nerve, and risk of developing depressive disorders. Utilizing extensive national health insurance data encompassing almost the entire Korean population, this cohort study included 11,745 patients with optic neuritis and 58,725 age- and sex- matched controls between 2010 and 2017. The diagnosis of optic neuritis was confirmed using ICD-10 code H46 and patient medical records. The association with depression risk identified by ICD-10 codes F32 and F33 was assessed using Cox proportional hazards regression models after adjusting for demographics, lifestyle variables, and other comorbidities. Newly diagnosed optic neuritis was associated with an increased risk of depression (hazard ratio = 1.349, 95% confidence interval: 1.277-1.426), independent of potential confounding factors. Subgroup analysis revealed a stronger association for individuals under 50 years, males, current smokers, and those without hypertension. This association suggests that autoimmune neuroinflammatory responses impact mental health differently across demographics. These findings underscore the importance of implementing routine depression screening and developing targeted early intervention strategies for patients with optic neuritis, particularly for those with a high-risk of depression.