Alison Chung

Topic

Examining Psychosocial Predictors of Cognition in Parkinsonism Across Time

Department of Psychology

Date & location

• Tuesday, August 13, 2024

• 1:00 P.M.

• Virtual Defence

Reviewers

Supervisory Committee

• Dr. Theone Paterson, Department of Psychology, University of Victoria (Supervisor)

• Dr. Colette Smart, Department of Psychology, UVic (Member) 

External Examiner

• Dr. Sandra Hundza, School of Exercise Science, Physical and Health Education, UVic 

Chair of Oral Examination

• Dr. Sue Whitesides, Department of Computer Science, UVic

   

Abstract

Background: Parkinsonism is a clinical syndrome that encompasses a spectrum of pathological difficulties including tremor, rigidity, abnormal slowness of movement, and postural instability, and affects between 108 to 212 per 100,000 older adults in North America per year. Rates of Parkinson’s disease (PD) related disability and death are also increasing more rapidly than any other neurological disorder. In addition to mobility disability, non-motor symptoms of parkinsonism such as changes in cognition occur as motor symptoms progress, as PD is associated with an increased risk of dementia. The cognitive reserve theory suggests that psychological and social factors may mitigate declines in cognition.

Objectives: There is currently a paucity of research examining relationships between psychosocial factors and cognition in the context of parkinsonism synergistically and across time. To address these gaps, this study aimed to examine relationships between mobility disability, parkinsonism, psychological well-being, social participation, and cognition both cross-sectionally and longitudinally.

Methodology: Cross-sectional path analyses included 1634 older adults from the Rush Memory and Aging Project (MAP); 1288 of which had sufficient follow-up assessments to conduct longitudinal growth curve analyses. Cognition was assessed across five domains: episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability.

Results: Cross-sectional analyses revealed that psychological well-being partially mediated increases in mobility disability associated with decreases in performance in episodic memory, semantic memory, working memory, and perceptual speed performance. Relationships between mobility disability and episodic memory, semantic memory, and perceptual speed, respectively were also partially mediated by social participation. Psychological well-being and social participation did not mediate declines in cognition associated with increases in parkinsonism. Longitudinal growth curve analyses supported the notion that more severe mobility disability and parkinsonism is associated with worse psychological well-being and social participation across time. The indirect paths within the longitudinal models also suggest that psychological wellbeing and social participation may mediate relationships between parkinsonism and mobility disability, respectively, and cognitive performance across all domains.

Conclusions: Results indicate that psychological well-being and social participation influence the effects of mobility disability and parkinsonism on cognition in differing manners. Findings indicate that psychological well-being interventions targeting reductions in anxiety, depression, and negative mood may be best suited for individuals with more severe mobility disability and may be most beneficial across the domains of episodic memory, semantic memory, working memory, and perceptual speed. Similarly, interventions targeting social participation may also be helpful to individuals with more severe mobility disability, and are most likely to impact episodic memory, semantic memory, and perceptual speed. For those with more severe mobility disability and parkinsonism, long-term psychological well-being and social participation-based interventions may be beneficial in targeting declines across all cognitive domains.