Incidence and risk factors of mental illnesses among patients with systemic autoimmune rheumatic diseases: an 18-year population-based study

Abstract Objective This study aimed to assess the incidence and risk factors surrounding mental illnesses in patients diagnosed with systemic autoimmune rheumatic diseases (SARDs). Methods This retrospective cohort study used nationwide, population-based claim data taken from Taiwan’s National Health Insurance Research Database (NHIRD) to identify patients certified as having a catastrophic illness for systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), dermatomyositis (DM), polymyositis (PM) or Sjögren’s syndrome (SS) from the years 2002–2020. We furthermore calculated the incidence of mental illness in patients diagnosed with SARDs while exploring factors associated with the development of mental illness using multivariable Cox regression analysis shown as adjusted hazard ratios (HRs) with 95% confidence intervals (CIs). Results Among the 28 588 participants, the average age was 47.4 (SD 14.9) years, with most participants being female (76.4%). When compared with patients with rheumatoid arthritis, patients with SLE (HR: 1.20, 95% CI: 1.10–1.32), SS (HR: 1.29, 95% CI: 1.19–1.39), and DM (HR: 1.28, 95% CI: 1.04–1.32) showed a significantly increased risk of developing mental illness. Additionally, when compared with patients with rheumatoid arthritis, patients with SLE (HR: 1.32, 95% CI: 1.21–1.44), SSc (HR: 1.20, 95% CI: 1.02–1.41), SS (HR: 1.17, 95% CI: 1.08–1.26), DM (HR: 1.73, 95% CI: 1.44–2.07), and PM (HR: 1.64, 95% CI: 1.32–2.03) showed a significantly increased risk of antidepressant use. Conclusion This population-based cohort study revealed that patients diagnosed with SLE, SS, and DM had significantly higher risks of developing mental illness when compared with patients with RA.