Objective: Cognitive impairment is a common nonmotor symptom in Parkinson's disease (PD). Individuals of Latino background are traditionally underrepresented in research on PD. Despite the fact that Latinos comprise 18% of the U.S. population, they commonly make up less than 5% of samples in studies of PD. Emerging evidence suggests that Latino individuals with PD may experience disparities relative to White non-Latinos in terms of having more severe motor symptoms, more severe depressive symptoms, and worse health-related quality of life. The purpose of the present study was to investigate differences in cognitive performance between Latino and White non-Latino individuals with PD and examine correlates of cognitive performance.

Methods: Data were obtained from the Parkinson's Progression Markers Initiative. Participants included 60 Latino individuals with PD and 1,009 White non-Latino individuals with PD, all of whom were followed annually for up to 5 years. Participants completed neuropsychological tests of attention and working memory, processing speed, visuospatial functioning, verbal fluency, and immediate and delayed memory and recall.

Results: Relative to White non-Latino individuals with PD, Latino individuals with PD had significantly lower scores on the global measure of cognitive functioning, a test of processing speed, and tests of working memory and attention. Years of education was the strongest correlate of performance in these three cognitive domains among individuals in the Latino group.

Conclusions: These findings provide initial evidence of disparities in cognitive functioning among Latino individuals with PD. Educational disadvantages may be one potential driver of these disparities.

Introduction: Parkinson's disease (PD) is a neurodegenerative disorder with motor and non-motor symptoms including depression and cognitive impairment. There is underrepresentation of Latinxs in PD research as most of the research consists of non-Latinx white participants. The current study investigates longitudinal differences in health disparities among Latinx and White non-Latinx individuals living with PD. As a second aim, we examined the associations between perceived discrimination in healthcare and outcomes from aim 1.

Methods: The present study consisted of 25,298 individuals with PD who enrolled in the Fox Insight (FI) online study. Participants were followed annually for up to 3 years. Participants completed measures of depressive symptoms, health-related quality of life (HRQOL), cognitive complaints, subjective motor symptom severity, self-reported income, and perceived discrimination in healthcare. Multilevel models examined the longitudinal differences in non-motor and motor outcomes among Latinx (n = 1161) and White non-Latinx individuals (n = 24,137).

Results: Latinx participants reported significantly more depressive symptoms and worse HRQOL than non-Latinx individuals. No significant differences were found in cognitive complaints, or motor severity between Latinx and non-Latinx participants. The main effect of perceived discrimination was associated with both depressive symptoms and HRQOL.

Conclusions: The current study provides initial evidence of mental health discrepancies among Latinx individuals living with PD and White non-Latinx counterparts. The combination of underrepresentation in research and possible health disparities among Latinx communities may affect the quality of clinical trials/studies and patient care.

Objective: Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder. About 40%-50% of PD patients experience depression, making it one of the most common neuropsychiatric disturbances in PD. Cognitive deficits (e.g., difficulties with memory, attention) are an additional common complication in PD. Past studies among healthy aging individuals suggest that depression is a risk factor for cognitive decline, and the risk increases with older age. This study aims to examine the association between depressive symptoms on cognitive decline as a function of age among patients with PD. It is hypothesized that older PD patients with more severe depressive symptoms will be at greater risk of cognitive decline than their younger or less depressed counterparts.

Methods: Four hundred and eighty-seven newly diagnosed patients with PD, were assessed for depression and cognition over a five-year period. Participants completed neuropsychological tests that assessed memory, learning, attention, visuospatial functioning, processing speed, and verbal fluency. Multilevel-modeling was used to examine the longitudinal association between cognition, age, and depressive symptoms.

Results: Our results indicated a significant three-way interaction (age X occasion X depressive symptoms) predicting language and working memory/attention performance. More specifically, detrimental associations of depressive symptoms on cognitive decline in these domains were more pronounced among older adults.

Conclusions: Our findings support that older PD patients with comorbid depressive symptoms experience greater cognitive decline compared to their younger counterparts. Findings suggest that older individuals with PD may be more vulnerable to neurotoxic effects of depression (e.g., neuroinflammation, HPA axis disruption), and better management of depression could potentially reduce cognitive decline and dementia risk.

Introduction: According to the Movement Disorder Society (MDS), subjective cognitive complaints (SCC) are a diagnostic criterion for PD-mild cognitive impairment (PD-MCI); however, studies often do not incorporate SCC when classifying PD-MCI. This inconsistent use may reflect mixed findings regarding the association between SCC and objective measures of cognitive impairment. Our study aimed to describe the extent that inclusion/exclusion of SCC affects the occurrence of PD-MCI, and if the inclusion of SCC is associated with faster cognitive decline and cerebrospinal fluid markers (CSF) of alpha-synuclein, amyloid beta, total tau, and phophorylated-tau.

Methods: Individuals with PD (N = 358) from the PPMI cohort whom completed measures of neuropsychological performance, subjective cognitive complaints, motor severity, and CSF markers were included. Participants were classified as cognitively normal (CN), PD-MCI with subjective cognitive complaints (PD-MCI + SCC) and PD-MCI without subjective cognitive complaints (PD-MCI -SCC).

Results: PD-MCI rates were consistently higher (16.5-19.1%) across the 5 years when SCC was not included in the diagnostic criteria as opposed to when SCC was included (4.4-11.0%). PD-MCI + SCC experienced greater cognitive decline and had significantly higher levels of tau/ab and p-tau/ab relative to both the CN and PD-MCI - SCC groups.

Conclusions: Inconsistent implementation of an SCC requirement in PD-MCI classifications may have important implications in terms of the occurrence of PD-MCI and its prognostic value. Classifying PD-MCI only using neuropsychological cut-off criterion, without regard to SCC, may lead to higher rates of PD-MCI. Inclusions of SCC in PD-MCI criteria in newly diagnosed PD participants may strengthen the ability to detect individuals at risk for future cognitive decline, though it is possible that this decline is related to Alzheimer's disease changes rather than worse PD pathology.