TABLE 3.

The etiopathogenesis of depression in psoriasis

DEPRESSION EXACERBATES PSORIASIS	PSORIASIS LEADS TO DEPRESSION	PSORIASIS AND DEPRESSION: SHARED ETIOPATHOGENIC MECHANISMS
By increasing the levels of pro-inflammatory cytokines, such as IL-6 and TNF-α36 By increasing the levels of substance P30 Depression modulates itch perception and exacerbates pruritus in psoriasis23	Maladaptive schemas16,31 Low sociocultural level; single; female; personal history of depression: higher risk for depression32,33 Sleep disorders9,14 Sexual disorders14,26 Pain and pruritus3,11,12,14,22,28,29,30 Disfigurement and stigmatization20,21 Lesions on face/genital area24 Higher PASI scores24	Abnormal calcium homeostasis39 High concentrations of substance P9,30 Defect in ß-adrenergic function15 Low melatonin secretion40 High levels of pro-inflammatory cytokines (IL-1, IL-6, TNF-α)37