The association between psoriasis and risk of psychiatric disorders has not been thoroughly evaluated in a large longitudinal cohort of Asian population. We conducted a nationwide population-based retrospective cohort study encompassing more than 1.6 million Koreans with a 12-year follow-up period. Patients were considered in the psoriasis cohort if they had an incident diagnostic code for psoriasis and included patients were followed up until they developed any psychiatric disease. In adjusted models, psoriasis patients (n = 10,868) were at a 18% increased risk for depression (hazard ratio [HR] 1.18, 95% confidence interval [CI] 1.09-1.26), 16% for anxiety disorders (HR 1.16, 95% CI 1.08-1.26), and 21% for somatoform disorders (HR 1.21, 95% CI 1.08-1.34) compared with the referent cohort (n = 1,620,055). Patients with moderate-to-severe psoriasis had a higher risk of developing depression and somatoform disorders than patient with mild disease (depression, HR 1.28, 95% CI 1.07-1.54 vs HR 1.17 95% CI 1.07-1.27; somatoform disorders, HR 1.60, 95% CI 1.26-2.03 vs HR 1.13, 95% CI 1.00-1.28). Our results highlight the burden of psychiatric diseases in patient with psoriasis in Korea and suggest that appropriate medical support for possible mental illness is warranted in Asian psoriatic patients.

The risk of psychiatric disorders among patients with psoriasis in Korea: a 12-year nationwide population-based cohort study