The Skin-Brain Axis in Psoriasis and Depression: Roles of Inflammation, Hormones, Neuroendocrine Pathways, Neuropeptides, and the Microbiome

Psoriasis, a common chronic inflammatory skin disease affecting approximately 2-3% of the global population, frequently co-occurs with depression. This highly prevalent comorbidity significantly impairs patients' quality of life. Despite the substantial physical and mental health burden imposed by psoriatic depression, the underlying pathophysiological mechanisms connecting psoriasis and depression remain poorly understood. In this review, we explored several pathological processes that may contribute to psoriasis-associated depression, including immune cells dysregulations, hormones imbalances, hypothalamic-pituitary-adrenal (HPA) axis dysfunctions, neuropeptides expression abnormalities, and gut dysbiosis. The primary purpose of this review was to present a comprehensive overview of the pathogenic mechanisms linking psoriasis and depression. These insights may guide trans-disciplinary interventions aimed at both skin and mood symptoms.