NPPB and major depressive disorder: All participants completed the Depression, Anxiety, and Stress Scale-21 items (DASS-21) and underwent blood collection for the assessment of inflammatory biomarkers such as C-Reactive Protein and its high-sensitivity detection (CRP/hs-CRP), Interleukins (IL-6, IL-1β) and Tumor Necrosis Factor alpha (TNF-α), metabolic biomarkers (vitamin D, cortisol, and D-dimer), and cardiac biomarkers such as N-terminal pro-B-type Natriuretic Peptide (NT-proBNP), Creatine Kinase-MB (CK-MB), troponin I (cTnI), and myoglobin (Myo).