Progress in Parkinson’s disease research highlights molecular markers, diagnostic tools, and potential treatments. Studies reveal gut metabolites linked to REM sleep behavior disorder, a Parkinson’s subtype, and identify EEG alpha peak frequency as a biomarker of cognitive impairment severity. Enzyme inhibition strategies restore neuronal pathways disrupted by LRRK2 mutations. Machine learning refines diagnosis, while optimized DBS approaches guide personalized treatment. Digital speech biomarkers measure levodopa effects, and novel pharmacological compounds show promise in modulating disease progression and motor/non-motor symptoms.