Risk of first-time and recurrent depression in patients with psoriasis - a population-based cohort study.

BACKGROUND: Psoriasis impairs quality of life, but it is unknown whether psoriasis is also an independent risk factor for depression.

OBJECTIVES: To evaluate incidence and risk of new and recurrent depression in patients with psoriasis.

METHODS: We used individual-level linkage of Danish administrative registers. Patients with psoriasis aged ≥18 years between January 1st , 1997 and December 31st , 2016 were matched 1:1 with non-psoriasis individuals. Incidence rates were calculated and adjusted hazard ratios (HRs) estimated by Cox regression.

RESULTS: There were 247,755 patients with psoriasis (220,721 treated with topical [mild psoriasis], 24,771 with systemic non-biologic [moderate psoriasis], and 2,263 with biologic therapy [severe psoriasis], respectively) and a similar number of matched non-psoriasis referents. During maximum 20 years follow-up, 45,641 patients with psoriasis and 36,299 referents developed depression. In adjusted models, HRs (95% CI) of depression were 1.19 (1.17-1.20), 1.19 (1.15-1.23) and 1.50 (1.23-1.84) for mild, moderate, and severe psoriasis, respectively. Highest risk was observed among severe psoriasis patients aged 40-50 years. Concurrent inflammatory bowel disease, but not psoriatic arthritis, was associated with increased risk of depression. Incidence of depression was markedly higher among patients with previous depression.

CONCLUSION: Psoriasis was independently associated with risk of depression. These results may help clinicians identify particularly high-risk individuals. This article is protected by copyright. All rights reserved.