Oxidative and Nitrosative Stress in Atopic Dermatitis and Depression: Similarities in Biomarkers and...

Atopic dermatitis is a chronic inflammatory skin disease characterized by epidermal barrier dysfunction and immune dysregulation, whereas major depressive disorder is a common psychiatric condition with a substantial impact on quality of life; increasing attention has been given to oxidative and nitrosative stress as a potential biological link between these disorders.

This narrative review synthesizes current evidence on molecular biomarkers of oxidative and nitrosative stress in AD and MDD and examines shared mechanisms within the skin-brain axis.

Across both conditions, studies consistently report increased markers of lipid peroxidation (e.g., malondialdehyde, 4-hydroxynonenal), oxidative DNA damage (8-hydroxy-2'-deoxyguanosine), and nitrosative stress, alongside impaired antioxidant defenses, particularly involving glutathione; these alterations are closely associated with chronic inflammation, cytokine signaling, mitochondrial dysfunction, and dysregulation of neuroimmune and hypothalamic-pituitary-adrenal axis pathways.

Although the available evidence is heterogeneous and largely based on cross-sectional studies, limiting causal inference, the findings support a biologically plausible link between AD and depression mediated by shared redox pathways and highlight the need for further longitudinal and mechanistic research.