The Correlation Between Apathy and the Efficacy of Rehabilitation in Patients With Parkinson's Disease: A Retrospective Observational Study

ABSTRACT Background Apathy impacts mood and social functioning in patients with Parkinson's disease (PWP), and its effect on motor rehabilitation outcomes remains unexplored. Objective This study evaluates whether the presence of apathy (apathy status) is associated with rehabilitation outcomes in PWP. Methods We retrospectively analyzed records of 122 PWP (Hoehn–Yahr stage ≤ 3) who underwent a 2‐week multidisciplinary intensive rehabilitation treatment (MIRT) between April 2020 and July 2024, dividing them into Parkinson's disease with apathy (PDA+, score > 14) and without apathy (PDA−, score ≤ 14) based on Modified Apathy Evaluation Scale (MAES). The outcome measures included the Movement Disorder Society Unified Parkinson's Disease Rating Scale part III (MDS‐UPDRS III), the Modified Parkinson Activity Scale (M‐PAS), the Five Times Sit to Stand Test (FTSTS), the Timed Up and Go Test (TUG), and the 10‐Meter Walk Test (10MWT). We conducted group comparisons and employed multiple linear regression analyses, treating the MAES both as a dichotomous variable and as a continuous predictor. In these analyses, we adjusted for baseline measures of MDS‐UPDRS III, FTSTS, and TUG. Additionally, we performed sensitivity analyses using alternative cutoffs (MAES > 13 and > 15). Results Following MIRT, the PDA– group ( n = 75) showed significant improvements in MDS‐UPDRS III, M‐PAS, FTSTS, and TUG ( p 14 vs. ≤ 14) produced similar results ( β = 2.378, 95% CI 0.341–4.415, p = 0.023; R 2 = 0.148). Sensitivity analyses using cutoffs of > 13 and > 15 yielded qualitatively comparable findings. Conclusions Baseline apathy severity was associated with attenuated motor improvement after MIRT in PWP; understanding its mechanisms is crucial for personalized rehabilitation and treatment effectiveness. Trial Registration ClinicalTrials.gov identifier: ChiCTR2000033768, 2020/06/11