Current depression is associated with systemic inflammation, specifically increased neutrophils in patients with psoriasis, especially women, according to a study published online Dec. 21 in the Journal of Investigative Dermatology .

Georgia Lada, M.D., from the University of Manchester in the United Kingdom, and colleagues used data from the U.K. Biobank for middle- to older-aged adults to examine the correlations of current and lifetime depression with neutrophil count, neutrophil-to-lymphocyte ratio (NLR), and high-sensitivity C-reactive protein (CRP) in psoriasis. The analysis included 5,485 psoriasis patients; 4,796 had lifetime depression data.

The researchers found that compared with patients on topicals or untreated patients, those on systemic treatment exhibited higher CRP, NLR, and neutrophil counts, suggesting higher systemic disease activity. No association was seen for CRP or NLR with current or lifetime depression, although there was a trend toward lifetime depression effect on CRP. When body mass index was omitted from models, CRP-depression associations were significant. Sex modified the effect of the association between neutrophils and the Patient Health Questionnaire (PHQ-2), which was used to assess current depression. For women, the association of PHQ-2 scores with neutrophil count was greater and significant, even after accounting for lifetime depression. In both sexes, lifetime depression was associated with higher neutrophil counts.

"The observed associations and their independence of lifestyle factors, comorbidities, and treatment-based psoriasis severity are suggestive of underlying immunological relationships with mood, particularly among women," the authors write. "It is important to elucidate further these associations in psoriasis through large prospective studies including multiple inflammatory markers."

Abstract/Full Text