NEFL and diabetes mellitus: Compared to previous predictive models, which primarily relied on psychological scales (Camerucci et al., 2024; Byeon, 2020), serum and cerebrospinal fluid neurofilament light chain (NfL) levels (Li et al., 2021; Urso et al., 2023), and radiomics-based approaches for predicting depressive symptoms and other non-motor symptoms in PD (Antar et al., 2021), this study introduces a novel approach by incorporating diabetes- and lipid-related clinical variables.