This study aimed to utilize the existing Parkinson’s Progression Markers Initiative (PPMI) dataset to investigate the relationship between measures of anxiety, depression, and motor function in people with Parkinson's Disease. The research focused on examining discrepancies in the relationship between clinician-assessed and participant-rated motor outcomes alongside the psychological symptoms of anxiety and depression.
Participant baseline PPMI data was accessed and condensed to provide a complete dataset for the following outcome measures: H&Y Scale, MoCA, GDS, STAI, and MDS-UPDRS (Parts II & III), also including relevant variables such as time since diagnosis and symptom onset. The condensed dataset included 1065 unique individuals with a diagnosis of Parkinson’s Disease. Correlational analyses were performed to examine relationships between variables, with a specific focus on the relationship between motor and non-motor outcomes. Additionally, we analyzed the similarity in correlations involving participant-rated and clinician-assessed measures of motor function. Multiple linear regression was completed to explore factors likely to predict symptoms of anxiety and depression.
In people with Parkinson’s Disease, both depression and anxiety were significantly associated with worse participant-reported motor function via MDS-UPDRS Part II (r = 0.313 and r = 0.284, respectively, p0.05). However, weaker correlations were found between depression/anxiety and clinician-assessed measures of motor function via MDS-UPDRS Part III (r = 0.079, p0.05 and r = 0.054, p=0.08 respectively). Multiple linear regression of data from people with Parkinson’s Disease explained 11.2% of the variance in depression and 10.5% of the variance in anxiety. Significant contributing factors in both cases included age, cognition, and participant-rated motor function.
This study reveals a significant mismatch in the relationship between psychological symptoms and clinician-assessed verses patient-reported motor function in people with Parkinson’s Disease. Our multiple linear regression analysis indicates that an individual's age, level of cognition, and perceived physical function may play an important role in this relationship. Our findings suggest that these factors may significantly affect patients' perception of their physical functioning. This highlights the importance of considering psychological factors and patient-reported motor function in physiotherapy assessment and treatment planning.
1. Physiotherapists should assess both objective motor function and participant-rated motor function in people with Parkinson’s Disease.
2. When discrepancies occur between clinician-assessed and patient-reported motor function, screening for anxiety/depression should be considered, with potential onward referral for psychological support.
3. Holistic approaches that consider motor and non-motor symptoms may lead to more effective, patient-centred interventions and improved outcomes in people with Parkinson’s Disease.
4. Further research is needed to explore how these relationships evolve over time, and considering a wider variety of motor outcomes.
Mental Health
Psycho-physical Relationship
