Abstract
Parkinson's Disease (PD) is a progressive neurodegenerative disorder. Depression, a prevalent comorbidity across all stages, exacerbates PD severity. α-synuclein aggregation, the hallmark of PD, drives pathways overlapping with depression. This review places α-synuclein at the nexus of mechanistic synergy between PD and depression, and incorporates secondary analyses of genomic and transcriptomic datasets to identify convergent genes and pathways, underscoring depression's potential as a biomarker for diagnosis and progression of PD.