Incidence and Risk of Depressive Disorder in Patients With Retinitis Pigmentosa

Importance There is a lack of large-scale clinical studies exploring mental health among patients with retinitis pigmentosa (RP). Additionally, few studies have evaluated the associations of visual impairment with mental health in young patients. Objective To investigate the association between depressive disorder and RP. Design, Setting, and Participants This was a retrospective, nationwide, population-based cohort study using data obtained from the Health Insurance Review and Assessment service in Korea between 2008 and 2022. A total of 10 879 individuals who were newly diagnosed with RP between January 2011 and December 2021, as verified by both the RP registration code (National Registry of Rare and Intractable Disease in Korea code V209) and diagnostic code (International Statistical Classification of Diseases, 10th Revision code H35.51), were included. Data analysis was performed from October 2023 to January 2024. Exposure Diagnosis of RP. Main Outcomes and Measures Participants were categorized into 3 groups based on age at diagnosis (<20, 20-39, and >= 40 years). The incidence of depressive disorder in RP was determined after excluding those diagnosed with depressive disorder prior to RP diagnosis. Age- and sex-adjusted standardized incidence ratios (SIRs) of depressive disorder in patients with RP compared with the general population were calculated. Subgroup analyses by sex and age group were conducted. Results A total of 10 879 patients (638 aged <20 years, 2233 aged 20-39 years, and 8008 aged >= 40 years; 5710 [52.5%] female) newly diagnosed with RP between 2011 and 2021 were included. The 10-year cumulative incidence of depressive disorder was 17.67% (95% CI, 16.57%-18.84%) in patients with RP. Subgroup analysis showed higher incidence of depressive disorder in female patients (hazard ratio [HR], 1.46; 95% CI, 1.29-1.65; P < .001) and those aged 40 years or older (HR, 1.93; 95% CI, 1.63-2.29; P < .001). The overall SIR of depressive disorder in patients with RP was 1.19 (95% CI, 1.12-1.27; P < .001), indicating a higher risk of depressive disorder compared with that in the general population. Both male and female patients with RP showed increased incidence rates of depressive disorder (17.53 [95% CI, 15.91-19.27] and 25.57 [95% CI, 23.58-27.67] per 1000 person-years, respectively) and increased SIRs of depressive disorder (1.21 [95% CI, 1.10-1.33] and 1.18 [95% CI, 1.09-1.28], respectively) (all P < .001) compared with the general population. Subgroup analysis by age group showed that the SIR peaked in patients in their 20s (1.50; 95% CI, 1.17-1.90; P = .006) and aged 60 years or older (1.25; 95% CI, 1.14-1.37; P < .001). Conclusions and Relevance Individuals diagnosed with RP had a higher risk of developing depressive disorder. These findings support consideration of providing emotional and social support to patients with RP.