Impact of Mood and Behavioral Disorders on Quality of Life in Parkinson's disease

Background: Mood symptoms negatively affect quality of life of Parkinson's disease (PD); however little is known about the impact of behavioral disorders such as impulse control disorders, and non-motor fluctuations on quality of life. Objective: To assess the impact of mood and behavioral disorders on quality of life in PD. Methods: 136 (84% male) PD were included (mean age: 61 +/- 8y; mean duration of disease: 8.8 +/- 5.4y). Mood symptoms, behavioral disorders and non-motor fluctuations were detected and quantified using the recently validated Ardouin Scale of Behavior in Parkinson's Disease. Motor symptoms were assessed using UPDRS and quality of life with the 39-item Parkinson's Disease Questionnaire. Results: Both motor and non-motor factors significantly affected the quality of life of PD patients. Multivariate regression of the relationship between items of the quality of life questionnaire and the Ardouin Scale showed that alteration of patients' quality of life was strongly correlated with the presence of mood symptoms (such as depression, anxiety...) and with non-motor fluctuations (especially in the OFF period). A significant correlation was also found between the number of symptoms and their severity, and the quality of life deterioration. Some behavioral disorders (compulsive buying / eating behavior) also negatively affected patient's quality of life to a lesser extent. Alternatively, excess in motivation and hobbyism behaviors had a positive impact on mobility and emotional well-being dimensions respectively of quality of life. Conclusions: This study shows the main impact of mood symptoms and non-motor fluctuations on worsening quality of life in PD.