Mental health disparities and the role of perceived discrimination among Latinx individuals living with Parkinson's disease.

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.

Synergistic associations of depressive symptoms and aging on cognitive decline in early Parkinson's disease.

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.

Intraindividual variability in neuropsychological performance predicts longitudinal cortical volume loss in early Parkinson's disease.

OBJECTIVE: Cognitive impairment is common among individuals with Parkinson's disease (PD). Intraindividual variability (IIV) is a measure of variability across multiple tasks of cognitive functioning. Due to the limited amount of research, particularly among individuals with PD, IIV has been an underutilized metric of cognitive functioning both in research and clinical practice. Previous research demonstrated that individuals with PD have greater variability in cognitive performance relative to controls, and that IIV is predictive of future cognitive impairments. The aim of this study is to investigate the association between baseline IIV and change in cortical and subcortical volumes among individuals with PD. METHOD: The present study used data from 80 newly diagnosed PD patients who were part of a longitudinal cohort study (Parkinson progression marker initiative [PPMI]). Participants completed neuropsychological measures and underwent T1 structural magnetic resonance imaging (MRI) at baseline and the first annual follow-up. Neuropsychological tests assessed attention, processing speed, visuospatial functioning, verbal fluency learning, and memory. T1 scans were processed using standard Freesurfer protocols for extraction of regional volumes. RESULTS: Greater IIV at baseline was predictive of change in cortical volume in posterior temporal/parietal regions over the 1-year period. Baseline IIV predicted cortical volume changes above and beyond the main effect of motor severity and the baseline statistical mean/global cognition score. CONCLUSION: Our results provide initial evidence that IIV is a marker of longitudinal cortical volume loss. Evidence is building that IIV is a sensitive marker of cognitive impairment and the underlying neurodegeneration among individuals with PD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A bidirectional relationship between anxiety, depression and gastrointestinal symptoms in Parkinson's disease.

INTRODUCTION: Anxiety, depression and gastrointestinal (GI) symptoms are common non-motor symptoms in Parkinson's disease (PD). Past studies provide evidence of a disrupted microbiome-gut-brain axis in PD, which is associated with certain motor and non-motor symptoms in PD. Additionally, there is evidence of a bidirectional association between mental health and gut health among individuals with GI disorders. The current study examined the bidirectional association between GI symptoms and anxiety/depression among individuals newly diagnosed with PD. METHODS: We conducted a secondary data analysis of the Parkinson's Progression Markers Initiative. This included 487 individuals newly diagnosed with PD and followed for up to 5 years. Participants completed questionnaires of anxiety, depression and GI symptoms (Scales for Outcomes in Parkinson's Disease Autonomic; SCOPA-AUT) at each annual visit. Multilevel models examined the bidirectional-lagged relationship between GI symptoms and anxiety/depression. RESULTS: Models provided evidence for a bidirectional relationship between GI symptoms and anxiety/depression. Specifically, more severe GI symptoms predicted more severe anxious/depressive symptoms within the same year and at the following year. There was also evidence of the inverse directionality, meaning that more severe anxiety/depression predicted more severe GI symptoms concurrently and in the following year. DISCUSSION: Findings provide preliminary evidence for a cyclical relationship among gut health and mental health in PD. Future studies are needed to examine if the microbiome-gut-brain axis plays a mechanistic role.