The non-motor side of the honeymoon period of Parkinson's disease and its relationship with quality of life: a 4-year longitudinal study.

Non-motor symptoms significantly increase over time, with a different progression rate for each one. NMSs significantly affect quality of life in PD and we here demonstrated that this was especially the case when patients were in their (motor) honeymoon period. Future trials should target non-dopaminergic networks and consider NMSs in their outcomes.