Current depression is associated with systemic inflammation, specifically increased neutrophils, mainly in females with psoriasis.

Current depression travels with increased neutrophils in psoriasis patients, especially females, finds research in the Journal of Investigative Dermatology.

For the study, researchers used data from the U.K. Biobank  to look at correlations between current and lifetime depression with neutrophil count, neutrophil-to-lymphocyte ratio (NLR), and high-sensitivity C-reactive protein (CRP) in psoriasis.  Of 5,485 psoriasis patients included in the study; 4,796 had lifetime depression data available.

Patients on systemic treatment exhibited higher CRP, NLR, and neutrophil counts, suggesting higher systemic disease activity when compared with patients on topicals or those who were untreated. There was no association for CRP or NLR with current or lifetime depression, but there was a trend toward lifetime depression effect on CRP. 

When researchers controlled for body mass index, CRP-depression associations were significant.   Sex modified the effect between neutrophils and the Patient Health Questionnaire (PHQ-2), which was used to assess current depression. “Our findings suggest an association of current depressive burden with systemic inflammation in the form of increased neutrophils in psoriasis, only among women,” the researchers report

Lifetime depression predicted higher neutrophil counts in psoriasis regardless of sex and also when accounting for current depression levels in women, the study showed.