Psoriasis, risk of depression in the US population

Psoriasis affects 3 percent to 4 percent of the U.S. population, and the psychological impact of psoriasis can be substantial. The identification of depression among patients with psoriasis is especially important because major depression is associated with decreased quality of life and increased all-cause mortality.

Roger S. Ho, M.D., M.S., M.P.H., of the New York University School of Medicine, New York, and coauthors examined the relationship between psoriasis and major depression in a nationally representative group, after adjusting for cardiovascular risk because prior research has suggested both depression and psoriasis are associated with cardiovascular disease. The authors analyzed data for participants in the National Health and Nutrition Examination Survey (NHANES) from 2009 through 2012. Diagnosis of major depression was based on a health questionnaire.

Authors identified 351 (2.8 percent) cases of psoriasis and 968 (7.8 percent) cases of major depression among 12,382 U.S. residents. There were 58 (16.5 percent) patients with psoriasis who met the criteria for a diagnosis of major depression. The average patient questionnaire score was higher among patients with a history of psoriasis than those patients without, according to the results.

Further analyses suggested the risk of major depression was not different between patients with limited vs. extensive psoriasis. A history of cardiovascular events did not affect the risk of major depression for patients with psoriasis. However, more patients with psoriasis (23.6 percent) reported that any symptoms of depression caused daily functional impairment, compared with patients without psoriasis (15.4 percent), according to the results.

The authors note limitations to the study, including the use cross-sectional data that prevents the establishment of a temporal relationship (which came first) between depression and psoriasis.

"Therefore, our study supports that all patients with psoriasis, regardless of severity, are at risk for depressive symptoms and may benefit from depression screening," the authors conclude.