Role of Serum Brain-Derived Neurotrophic Factor as a Biomarker of Chronic Pain in Older Adults - Ortola, R; Sotos-Prieto, M; Carballo, A; Cabello-Plan, S; Koni, Aida; Mustieles, V; Garcia-Segura, L M; Artalejo, A R; Rodriguez-Artalejo, F; Garcia-Esquinas, E (EUROPEAN JOURNAL OF PAIN, 2025)