Perceived stress and cognition shape the early clinical presentation of Parkinson's disease

Parkinson's disease (PD) is a multisystem disorder in which non-motor symptoms, cognitive impairment, and psychological stress are present from the earliest stages. Their interrelationship at diagnosis in drug-naïve patients remains insufficiently characterized. This study investigated associations between motor symptoms, non-motor symptoms, cognition, and perceived versus objective stress in newly diagnosed, drug-naïve PD patients.

This cross-sectional study included 52 newly diagnosed, drug-naïve PD patients enrolled between July 2020 and December 2022. Assessments included the Unified Parkinson's Disease Rating Scale (UPDRS I-III), Non-Motor Symptoms Questionnaire (NMSQ), Montreal Cognitive Assessment (MoCA), National Stress Assessment Day questionnaire (NSAD) for perceived stress, and Holmes-Rahe Life Stress Inventory (HRLSI) for objective stress. Spearman correlation and Mann-Whitney U tests were applied.

Non-motor symptoms were significantly associated with both functional and motor impairment (NMSQ correlated with UPDRS I, ρ = 0.56; patients with higher NMSQ had higher UPDRS II, p = 0.005, and UPDRS III, p = 0.020). Perceived stress (NSAD) correlated with higher UPDRS I scores (ρ = 0.41, p = 0.005), while objective life stress (HRLSI) showed no significant associations. Patients with lower cognitive performance (MoCA <26) had significantly higher UPDRS I (p = 0.008) and NMSQ scores (p = 0.027).

In newly diagnosed PD, perceived stress and cognitive function are independently associated with non-motor symptom burden, while objective life stress appears clinically less relevant. These findings support a multidimensional approach to early PD assessment that integrates psychological stress appraisal and cognitive screening alongside standard motor evaluation.