Depressive symptoms precede cognitive impairment in de novo Parkinson's disease patients: Analysis of the PPMI cohort

Can we detect cognitive "super-agers" in Parkinson's disease? Cognitive, neuropsychiatric and motor outcomes in the first 10 years of Parkinson's disease

INTRODUCTION

Superagers are older individuals who resist age-related cognitive decline and who perform just as well or better than younger people in cognitive tasks. In healthy aging studies, superagers not only experience positive cognitive outcomes (e.g. lower risk of future mild cognitive impairment), but may also experience fewer depressive and anxiety symptoms as they age. We seek to identify superagers in Parkinson's disease (PD) and potential outcomes associated with superager status.

METHODS

Data was gathered from the Parkinson's Progression Markers Initiative (PPMI). 689 individuals newly diagnosed with PD were assessed annually for up to 10 years. Participants were classified into three groups: superagers, cognitively normal, and PD mild cognitive impairment (PD-MCI). Multilevel models examined longitudinal group differences in global cognition, depression, anxiety, and motor severity.

RESULTS

A significant main effect of group revealed that superagers performed better than the PD-MCI and cognitively normal groups in global cognition. There were significant group by time interactions, revealing the superagers group was on a more favorable longitudinal trajectory relative to other two groups. Superagers also reported less severe depressive and anxiety symptoms compared to the PD-MCI and the cognitively normal groups. Superagers had a more favorable trajectory of motor symptom severity relative to the cognitively normal and PD-MCI groups.

CONCLUSION

Superagers with PD may be detected with neuropsychological testing and appear to resist the effects of neurodegeneration in Parkinson's disease. Cognitive studies and trials may benefit from incorporating the concept of superagers, as opposed to a single homogenous cognitively normal group.

Impact of Anticholinergic Burden and Clinical-Demographic Characteristics on Incident Dementia in Parkinson Disease

PURPOSE

Anticholinergic medication use measured via the Anticholinergic Cognitive Burden (ACB) scale has been associated with an increased dementia incidence in older adults but has not been explored specifically for Parkinson disease dementia (PDD). We used adjusted Cox models to estimate the risk of incident PDD associated with demographic factors, clinical characteristics, and time-varying total ACB in a longitudinal, deeply-phenotyped prospective PD cohort.

MAJOR FINDINGS

56.5% of study participants were taking ACB-scale drugs at enrollment. Increasing age, motor symptom burden and psychosis were associated with PDD risk. Female sex and educational achievement were protective against PDD. ACB categories were not associated with PDD overall, but depression and impulse control disorder were strongly associated with PDD in a subsample with high baseline ACB.

CONCLUSIONS

Patient and clinical factors modify PDD risk. PD drug safety and drug-disease interaction studies may require considering multiple mechanisms and including dose-based, prospectively acquired medication exposure measures.

Temporal Sequence of Cognitive Function and ADLs and Mediation Effect of Apathy in Parkinson's Disease: Cross-Lagged Analyses

OBJECTIVES

To explore the temporal sequence between cognitive function and activities of daily living (ADLs) in patients with Parkinson's disease (PD) and investigate whether apathy mediates these effects.

METHODS

We recruited 486 patients from the Parkinson's Progression Marker Initiative. We constructed a cross-lagged panel model to explore the temporal sequence between cognitive function and ADLs and analyzed the longitudinal mediating effect of apathy on the relationship between cognitive function and ADLs.

RESULTS

The slopes of ADLs and cognitive function were significant (p < .001), and lower levels of cognitive function indicated lower ADLs, suggesting that a decreased cognitive performance preceded ADLs decline. Cognitive function influenced apathy (negatively) (p < .001) and ADLs (p < .001). A significant indirect effect of cognitive function on ADLs through apathy was revealed by bias-corrected bootstrapping (β = 0.181, p < .001).

CONCLUSIONS

The rate of change in cognitive function was significantly correlated with that of ADLs, and a decreased cognitive performance preceded ADLs decline. Cognition was indirectly related to ADLs through apathy.

CLINICAL IMPLICATIONS

The rate of change in cognitive function in patients with PD was correlated with that of ADLs, and a decreased cognitive performance preceded ADLs decline. Reducing apathy represents a promising approach to reducing the impact of cognitive decline on ADLs.

Associations between cognitive screening performance and motor symptoms in Parkinson's disease:a systematic review and meta-analysis

Although the most prominent symptoms of Parkinson's disease (PD) are those impacting movement, cognitive dysfunction is prevalent and often presents early in the disease process. Individuals with cognitive symptoms of PD often complete cognitive screening, making it important to identify factors associated with cognitive screening performance to ensure prompt and accurate detection of cognitive impairments.

Objective

Despite a body of research examining relationships between motor symptoms and cognitive dysfunction in PD, no prior study has undertaken a systematic review of the magnitude of the relationship between motor symptoms and cognitive screening performance in PD.

Methods

This study was a systematic review and meta-analysis of the relationship between cognitive screening performance, as assessed by the Montreal Cognitive Assessment (MoCA), and motor symptoms of PD. After the systematic screening, 20 studies were included, and meta-regressions using mixed-effects models were conducted.

Results

Motor symptoms across included studies were relatively mild, but average MoCA scores were at the established cutoff for risk of dementia in PD. The average disease duration was 5 years. Consistent with hypotheses, more severe motor symptoms were associated with lower MoCA scores (r=-0.22 (95%CI -0.29 to -0.16), p<0.001), indicating worse cognitive functioning.

Conclusion

The results indicate a significant negative correlation between MoCA performance and motor symptoms of PD. Average MoCA scores captured early disease-stage cognitive impairment when motor symptoms remained relatively mild. Serial screening for cognitive impairment beginning early in the disease course may be of benefit to ensure that cognitive dysfunction is detected as it arises.

Cognitive Performance of Latino and White Non-Latino Individuals With Parkinson's Disease

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.

Baseline Depressive Symptoms as a Predictor of Incident Dementia in a Prospectively Followed Cohort of Elders with Essential Tremor

INTRODUCTION

Essential tremor (ET) patients may exhibit a variety of non-motor features, including cognitive decline and depressive symptoms. Studies of several neurodegenerative diseases link depression to cognitive decline, suggesting depression is an early marker of dementia. We examined whether baseline depressive symptoms predict incident dementia in elders with ET.

METHODS

Hundred and forty-one ET cases aged 70 years or older at baseline, enrolled in a prospective study of cognitive performance, took part in evaluations at baseline and at 18, 36, 54, and 72 months. Participants completed the Geriatric Depression Scale (GDS), a 30-item self-report measure of depressive symptoms, and a battery of neuropsychological tests and functional assessments, from which we derived cognitive diagnoses at each evaluation. Cox proportional hazards regression equations determined incident dementia risk based on participants' baseline depression scores.

RESULTS

Mean baseline age was 81.5 ± 6.7 years. Higher baseline GDS scores were associated with increased risk of dementia in an unadjusted model (hazards ratio [HR] = 1.11, 95% confidence interval [CI] = 1.02-1.20, p = 0.01) and after controlling for baseline age, education, number of medications, and tremor onset age (HR = 1.13, 95% CI = 1.02-1.25, p = 0.02).

CONCLUSION

Baseline depression scores predicted incident dementia in elders with ET. With each one-point increase in baseline depression score, there was a 13% increase in incident dementia risk. Given the published data that reported depression may be twice as high in elders with ET compared to controls, this association is particularly worrisome in the ET population.

Depression in dementia with Lewy bodies: a critical update

Depression with an estimated prevalence of 35% is a frequent manifestation of dementia with Lewy bodies (DLB), having negative effects on cognitive performance and life expectancy, yet the underlying neurobiology is poorly understood and most likely heterogeneous. Depressive symptoms in DLB can occur during the clinical course and, together with apathy, is a common prodromal neuropsychiatric symptom of this neurocognitive disorder in the group of Lewy body synucleinopathies. There are no essential differences in the frequency of depression in DLB and Parkinson disease-dementia (PDD), while its severity is up to twice as high as in Alzheimer disease (AD). Depression in DLB that is frequently underdiagnosed and undertreated, has been related to a variety of pathogenic mechanisms associated with the basic neurodegenerative process, in particular dysfunctions of neurotransmitter systems (decreased monoaminergic/serotonergic, noradrenergic and dopaminergic metabolism), α-synuclein pathology, synaptic zinc dysregulation, proteasome inhibition, gray matter volume loss in prefrontal and temporal areas as well as dysfunction of neuronal circuits with decreased functional connectivity of specific brain networks. Pharmacotherapy should avoid tricyclic antidepressants (anticholinergic adverse effects), second-generation antidepressants being a better choice, while modified electroconvulsive therapy, transcranial magnetic stimulation therapy and deep brain stimulation may be effective for pharmacotherapy-resistant cases. Since compared to depression in other dementias like Alzheimer disease and other parkinsonian syndromes, our knowledge of its molecular basis is limited, and further studies to elucidate the heterogeneous pathogenesis of depression in DLB are warranted.

Longitudinal cognitive changes in patients with early Parkinson's disease and neuropsychiatric symptoms

AIMS

In this study, we aimed to investigate the effect of neuropsychiatric symptoms (NPS) on the rate of cognitive decline for both global cognition and specific cognitive domains in a cohort of patients from the Parkinson's Progression Markers Initiative (PPMI).

METHOD

Prospectively longitudinal data were obtained from the PPMI cohort. NPS, including depression, anxiety, apathy, psychosis, impulse control disorders (ICDs), and cognition ability, were evaluated by a series of questionnaires. Linear mixed-effects models were used to investigate the relationship between NPS and the rate of cognitive decline. Generalized estimating equations (GEEs) were used to investigate the relationship between NPS and the occurrence of mild cognitive impairment (MCI).

RESULTS

In total, 423 patients with Parkinson's disease (PD) were recruited at baseline and 395, 378, 366, 346, and 315 participants were followed up at 1, 2, 3, 4, and 5 years, respectively. Depression, anxiety, apathy, and psychosis were associated with global cognitive decline. Except for those with ICDs, patients with psychosis, depression, anxiety, and apathy were more likely to meet the criteria for MCI. Patients with depression and anxiety showed a progressive decline in four major cognitive domains. Apathy and ICDs were separately associated with a progressive decline in processing speed-attention and memory, respectively.

CONCLUSIONS

Neuropsychiatric symptoms, including psychosis, depression, anxiety, and apathy, could be used to predict future cognitive decline in patients with PD.

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.

Depression in Major Neurodegenerative Diseases and Strokes: A Critical Review of Similarities and Differences among Neurological Disorders

Depression and anxiety are highly prevalent in most neurological disorders and can have a major impact on the patient's disability and quality of life. However, mostly due to the heterogeneity of symptoms and the complexity of the underlying comorbidities, depression can be difficult to diagnose, resulting in limited recognition and in undertreatment. The early detection and treatment of depression simultaneously with the neurological disorder is key to avoiding deterioration and further disability. Although the neurologist should be able to identify and treat depression initially, a neuropsychiatry team should be available for severe cases and those who are unresponsive to treatment. Neurologists should be also aware that in neurodegenerative diseases, such as Alzheimer's or Parkinson's, different depression symptoms could develop at different stages of the disease. The treatment options for depression in neurological diseases include drugs, cognitive-behavioral therapy, and somatic interventions, among others, but often, the evidence-based efficacy is limited and the results are highly variable. Here, we review recent research on the diagnosis and treatment of depression in the context of Alzheimer's disease, Parkinson's disease, and strokes, with the aim of identifying common approaches and solutions for its initial management by the neurologist.

The pathobiological basis of depression in Parkinson disease: challenges and outlooks

Depression, with an estimated prevalence of about 40% is a most common neuropsychiatric disorder in Parkinson disease (PD), with a negative impact on quality of life, cognitive impairment and functional disability, yet the underlying neurobiology is poorly understood. Depression in PD (DPD), one of its most common non-motor symptoms, can precede the onset of motor symptoms but can occur at any stage of the disease. Although its diagnosis is based on standard criteria, due to overlap with other symptoms related to PD or to side effects of treatment, depression is frequently underdiagnosed and undertreated. DPD has been related to a variety of pathogenic mechanisms associated with the underlying neurodegenerative process, in particular dysfunction of neurotransmitter systems (dopaminergic, serotonergic and noradrenergic), as well as to disturbances of cortico-limbic, striato-thalamic-prefrontal, mediotemporal-limbic networks, with disruption in the topological organization of functional mood-related, motor and other essential brain network connections due to alterations in the blood-oxygen-level-dependent (BOLD) fluctuations in multiple brain areas. Other hypothetic mechanisms involve neuroinflammation, neuroimmune dysregulation, stress hormones, neurotrophic, toxic or metabolic factors. The pathophysiology and pathogenesis of DPD are multifactorial and complex, and its interactions with genetic factors, age-related changes, cognitive disposition and other co-morbidities awaits further elucidation.

Physical inactivity links depressive symptoms and cognitive functioning among individuals with Parkinson's disease

OBJECTIVE

Parkinson's disease (PD) is a neurodegenerative disorder caused by disruption of dopamine-producing cells. PD is associated with motor symptoms and nonmotor symptoms including depression and cognitive impairment. Past research suggests an association between depression and cognitive impairment in PD. Physical activity may have a therapeutic effect on both depression and cognitive impairment. The present study investigates if physical activity mediates the association between depressive symptoms and cognition in a longitudinal sample of individuals with PD.

METHOD

Participants include individuals newly diagnosed with PD (N = 487) enrolled in the Parkinson's Progression Marker Initiative (PPMI). Participants completed an array of neuropsychological tests over the course of 5 years, as well as questionnaires of depression and physical activity. Between-person and within-person effects of depression and cognition mediated through physical activity were analyzed using structural equation modeling.

RESULTS

A significant direct effect demonstrated depression was associated with worse global cognitive functioning. Furthermore, there was a significant indirect within-person effect, indicating that physical activity fully mediated the association between depression and cognition. Individuals who became more depressed over time became less physically active and subsequently experienced cognitive decline over the 5-year period.

CONCLUSIONS

Findings have implications for prognostic detection and/or the role of physical activity interventions to buffer effects of depression on cognitive impairment among individuals diagnosed with PD. Physical interventions may potentially be implemented among depressed persons to preserve cognitive functioning. Worsened depression early during PD may be a risk factor for inactivity and cognitive diminishment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Associations of cognitive dysfunction with motor and non-motor symptoms in patients with de novo Parkinson's disease

The risk factors of mild cognitive impairment (MCI) in patients with de novo Parkinson’s disease (PD) remain unclear. Therefore, the objective of this study was to compare motor and non-motor symptoms between de novo patients with PD with and without MCI. Moreover, detailed relationships between each cognitive deficit and other clinical characteristics in de novo patients with PD were investigated. Consecutive patients with de novo PD were retrospectively enrolled in this study. Motor symptoms were assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS) part-III and the Hoehn and Yahr (HY) stage. Non-motor symptoms including depression, anxiety, fatigue, and autonomic dysfunction were measured using representative questionnaires. Motor symptoms, depression, and dysautonomia were associated with MCI in de novo patients with PD. Compared with the non-MCI group with PD, the MCI group with PD had higher scores of UPDRS-III, HY stage, depression, and dysautonomia, but not fatigue or anxiety. Both UPDRS-III and HY stage were significantly linked to all cognitive deficits except attention. Logistic regression analysis showed that depression was associated with memory, visuospatial, and executive impairment, and dysautonomia was related to visuospatial and executive impairment. The results of this study suggest that cognitive impairment in PD might have a different relationship pattern to the motor and some non-motor symptoms.

Associations of Sleep Disorders With Depressive Symptoms in Early and Prodromal Parkinson's Disease

Background

Non-motor symptoms, including sleep disorders and depression, are common in Parkinson’s disease (PD). The purpose of our study is to explore the effect of sleep disorders, including the probable rapid eye movement (REM) sleep behavior disorder (pRBD) and the daytime sleepiness, on depressive symptoms in patients with early and prodromal PD.

Methods

A total of 683 participants who obtained from the Parkinson Progression Markers Initiative (PPMI) were included, consisting of 423 individuals with early PD, 64 individuals with prodromal PD, and 196 healthy controls (HCs), who were followed up to 5 years from baseline. Multiple linear regression models and linear mixed-effects models were conducted to explore the relationship between sleep disorders and depression at baseline and longitudinally, respectively. Multiple linear regression models were used to further investigate the association between the change rates of daytime sleepiness score and depression-related score. Mediation analyses were also performed.

Results

At baseline analysis, individuals with early and prodromal PD, who had higher RBD screening questionnaire (RBDSQ) score, or who were considered as pRBD, or who manifested specific behaviors of RBD (things falling down when sleep or disturbance of sleep), showed significantly the higher score of depression-related questionnaires. Our 5-year follow-up study showed that sleep disorders, including pRBD and daytime sleepiness, were associated with the increased depressive-related score in individuals with early and prodromal PD. Interestingly, we also found that the increased possibilities of daytime sleepiness were associated with depressive-related score. Finally, mediation analysis demonstrated that the relationship between RBD and depressive symptoms was partially mediated by autonomic symptoms, such as postural hypertension, salivation, dysphagia, and constipation.

Conclusion

Our study shows that sleep disorders, including pRBD and daytime sleepiness, are associated with depression at baseline and longitudinally, which is partially mediated by the autonomic dysfunction in early and prodromal PD, with an implication that sleep management is of great value for disease surveillance.

Comparative efficacy and acceptability of drug treatments for Parkinson's disease with depression: A systematic review with network meta-analysis

Depressive symptom is the prevailing non-motor symptom of Parkinson's disease (PD). Drug treatments for depressed PD (dPD) can mitigate the symptoms of patients. However, the results are discordant and need further analysis. This systematic review with network meta-analysis aims to evaluate the drug treatments for dPD. We included double-blind, randomized controlled trials to compare antidepressants with placebo or other antidepressants in dPD. We performed traditional pairwise analysis and network meta-analysis concerning the efficacy, acceptability, depression score, and adverse effect. The surface under the cumulative ranking curve was to assess the ranking probabilities of the enrolled agents. We enrolled 62 studies, including 12,353 subjects, to analyze these estimates. For the traditional pairwise meta-analysis, dopamine agonist (DOP; OR = 2.20 [95% CI, 1.46 to 3.33]) and selective serotonin reuptake inhibitor (SSRI; OR = 2.30 [95% CI, 1.15 to 4.60]) were observed to improve the efficacy compared with placebo. For network meta-analysis, DOP was observed to improve the efficacy compared with placebo (OR = -0.84 [95% CI, -1.20 to -0.48]). Both direct and indirect evidence showed that several treatments, e.g., DOP, monoamine-oxidase inhibitor, serotonin-norepinephrine reuptake inhibitors, SSRI, and tricyclic antidepressants, significantly improved depressive symptoms. DOP and SSRI had good efficacy and improved symptoms considerably in dPD, but the adverse effect of these agents was needed to follow closely.

Apathy as a Within-Person Mediator of Depressive Symptoms and Cognition in Parkinson's Disease: Longitudinal Mediation Analyses

OBJECTIVE

Greater depressive symptoms are associated with worse cognitive functions in Parkinson's disease (PD); however, it is unclear what underlying factors drive this association. Apathy commonly develops in PD and may be a pathway through which depressive symptoms negatively influence cognition. Prior research examining depressive symptoms, apathy, and cognition in PD is limited by being predominantly cross-sectional. This study examined the role of apathy as a within- and between-person mediator for the longitudinal relationships between depression severity and cognitive functioning in patients with early PD.

METHODS

Participants included 487 individuals newly diagnosed with PD followed annually for up to 5 years by the Parkinson's Progression Marker Initiative. At each visit, participants completed depressive symptom measures, apathy ratings, and cognitive tests. Multi-level structural equation models examined both the within- and between-person effects of depressive symptoms on cognition through apathy, controlling for demographics and motor severity.

RESULTS

At the within-person level, apathy mediated the association between depressive symptoms and select cognitive functions (global cognition, attention/working memory, visuospatial functions, and immediate verbal memory; indirect effects, bootstrap p's <0.05). Significant between-person direct effects were found for depressive symptoms predicting apathy (boostrap p <0.001) and lower scores on most cognitive tests (bootstrap p's <0.05). However, the indirect effects did not reach significance, suggesting between-person mediation did not occur.

CONCLUSION

Findings suggest worsening of depressive symptoms over time in patients with PD may be a risk factor for increased apathy and subsequent decline in specific cognitive functions.

Depression in Patients with Parkinson's Disease: Current Understanding of its Neurobiology and Implications for Treatment

Depression is one of the most frequent and burdensome non-motor symptoms in Parkinson’s disease (PD), across all stages. Even when its severity is mild, PD depression has a great impact on quality of life for these patients and their caregivers. Accordingly, accurate diagnosis, supported by validated scales, identification of risk factors, and recognition of motor and non-motor symptoms comorbid to depression are critical to understanding the neurobiology of depression, which in turn determines the effectiveness of dopaminergic drugs, antidepressants and non-pharmacological interventions. Recent advances using in vivo functional and structural imaging demonstrate that PD depression is underpinned by dysfunction of limbic networks and monoaminergic systems, depending on the stage of PD and its associated symptoms, including apathy, anxiety, rapid eye movement sleep behavior disorder (RBD), cognitive impairment and dementia. In particular, the evolution of serotonergic, noradrenergic, and dopaminergic dysfunction and abnormalities of limbic circuits across time, involving the anterior cingulate and orbitofrontal cortices, amygdala, thalamus and ventral striatum, help to delineate the variable expression of depression in patients with prodromal, early and advanced PD. Evidence is accumulating to support the use of dual serotonin and noradrenaline reuptake inhibitors (desipramine, nortriptyline, venlafaxine) in patients with PD and moderate to severe depression, while selective serotonin reuptake inhibitors, repetitive transcranial magnetic stimulation and cognitive behavioral therapy may also be considered. In all patients, recent findings advocate that optimization of dopamine replacement therapy and evaluation of deep brain stimulation of the subthalamic nucleus to improve motor symptoms represents an important first step, in addition to physical activity. Overall, this review indicates that increasing understanding of neurobiological changes help to implement a roadmap of tailored interventions for patients with PD and depression, depending on the stage and comorbid symptoms underlying PD subtypes and their prognosis.

Depressive symptoms predict memory decline in Essential Tremor

INTRODUCTION

Essential tremor (ET), a common movement disorder, is characterized by motor, cognitive and psychiatric symptoms. Depressed mood, a symptom of ET, has historically been viewed as a psychological response to disability. However, depressive symptoms are emerging as a predictor of cognitive decline across several clinical populations. We examined if depressive symptoms predict decline in global cognition, memory, and executive functioning among older adults with ET.

METHODS

125 cognitively normal participants with ET completed three in-person assessments of cognition, mood, and motor symptoms at baseline, 18 months, and 36 months; baseline data were collected from July 2014-July 2016. Depressive symptoms were measured with the Geriatric Depression Scale. Cognitive functioning was measured via a 3-4 hour neuropsychological evaluation. Generalized linear regression models examined depressive symptoms as a predictor of decline in global cognition, executive functioning (EF), and memory.

RESULTS

Participants were grouped according to a median split (GDS <5 versus ≥ 5) due to the bimodal distribution of the data. In unadjusted models, depressive symptoms did not predict change in global cognition (b = -0.002, p = .502) or EF (b = 0.000, p = .931), however individuals with GDS ≥ 5 demonstrated faster memory decline in unadjusted (b = -0.008, p = .039) and adjusted models (b = -0.009, p = .019).

CONCLUSION

The presence of 5 or more depressive symptoms predicted mildly faster memory decline in cognitively normal older adults with ET over 36 months. We discuss potential mechanisms and clinical implications.

Cognitive dysfunction and neuropsychiatric aspects of Parkinson's disease

Movement abnormalities, by definition, and cognitive changes, to varying extents, affect every patient with Parkinson's disease (PD) and are attributed to the underlying neurodegenerative disease. Various psychiatric disorders occur in most patients at some point over the course of PD, including in the prodromal phase. Even though psychiatric disturbances tend to aggravate motor and cognitive deficits, they are under-recognized and under-treated, and the role of the underlying neurological disease is often minimized. To provide an integrated approach to understanding neuropsychiatric aspects of PD, this chapter reviews how cognitive changes in PD relate to the common psychiatric disturbances in PD along with the prevalence, phenomenology, pathophysiology, and treatment of each.

Anxiety, Depression, and Apathy as Predictors of Cognitive Decline in Patients With Parkinson's Disease-A Three-Year Follow-Up Study

Objective

Anxiety, depression, and apathy are the most common neuropsychiatric symptoms in Parkinson's disease (PD) patients. They impair cognitive functioning and have a profound impact on quality of life. This follow-up study aims to investigate the predictive value of anxiety, depression, and apathy on the development of Mild Cognitive Impairment (MCI) in PD patients.

Methods

Twenty-nine cognitively unimpaired PD patients (mean age 68.2 SD ± 7.12 years; 13 women) participated in this study. At Baseline (BL) levels of apathy (Apathy Evaluation Scale, AES), depression (Beck Depression Inventory, BDI-II), and anxiety (Beck Anxiety Inventory, BAI), were assessed. Cognitive status was reassessed three years later according to MCI/non-MCI status. For statistics, we used binary logistic regression and receiver operating characteristic curve (ROC) analysis to examine anxiety, apathy, and depression at BL as a predictor of MCI status three years later.

Results

Eight of the 29 patients developed MCI. Anxiety level at BL was found to predict MCI status at three-year follow-up (OR = 1.20, CI = 1.02–1.41, p = 0.02), while depression (OR = 1.16, CI = 0.93–1.47, p = 0.20) and apathy (OR = 1.06, CI = 0.92–1.23, p = 0.40) did not predict MCI status. The area under the ROC curve (AUC) of BAI for discriminating PD-non-MCI from PD-MCI was 0.79 (CI = 0.61–0.98). The optimal classification threshold yielded a sensitivity of 75.0 % and a specificity of 76.2 %. Neither apathy nor depression at BL discriminated between PD-non-MCI patients from PD-MCI three years later.

Conclusions

This study shows an association between anxiety and the development of MCI in PD patients, although the association between apathy, depression, and MCI did not reach a significant level.

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

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Gastrointestinal (GI) and mood symptoms are common in Parkinson’s disease.

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Depression and anxiety are bidirectional risk factors for GI distress.

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Association between GI and mood symptoms may reflect disrupted Gut-Brain axis.

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.

Informant-Reported Cognitive Decline is Associated with Objective Cognitive Performance in Parkinson's Disease

OBJECTIVE

The utility of informant-based measures of cognitive decline to accurately describe objective cognitive performance in Parkinson's disease (PD) without dementia is uncertain. Due to the clinical relevance of this information, the purpose of this study was to examine the relationship between informant-based reports of patient cognitive decline via the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) and objective cognition in non-demented PD controlling for cognitive status (i.e., mild cognitive impairment; PD-MCI and normal cognition; PD-NC).

METHOD

One-hundred and thirty-nine non-demented PD participants (PD-MCI n = 38; PD-NC n = 101) were administered measures of language, executive function, attention, learning, delayed recall, visuospatial function, mood, and motor function. Each participant identified an informant to complete the IQCODE and a mood questionnaire.

RESULTS

Greater levels of informant-based responses of patient cognitive decline on the IQCODE were significantly associated with worse objective performance on measures of global cognition, attention, learning, delayed recall, and executive function in the overall sample, above and beyond covariates and cognitive status. However, the IQCODE was not significantly associated with language or visuospatial function.

CONCLUSIONS

Results indicate that informant responses, as measured by the IQCODE, may provide adequate information on a wide range of cognitive abilities in non-demented PD, including those with MCI and normal cognition. Findings have important clinical implications for the utility of the IQCODE in the identification of PD patients in need of further evaluation, monitoring, and treatment.

Evaluation of the cognitive impairments and depressive symptoms in patients with Parkinson's disease: A case-control study from Iran

BACKGROUND

Parkinson's disease is a progressive neurodegenerative disease and the second most common neurological disease in the world, which usually affects people mainly in later years of life. Cognitive impairments and depressive symptoms are important symptoms in these patients that are associated with a poor prognosis. The study will focus on the original data regarding the cognitive impairments and depressive symptoms in patients with Parkinson's disease and control group.

METHODS

In a case-control study, a total of 100 Parkinson's patients who were hospitalized in Rouhani Hospital and 200 non-Parkinson's people (control group) from Amirkola Health and aging project (AHAP) Marras et al., Babol, Iran were enrolled between September 2019 to February 2020. Data were collected by simple random sampling. Data were collected using a four-part questionnaire, including demographic characteristics, Unified Parkinson Disease Rating Scale (UPDRS), Modified Hoehn and Yahr staging Scale (MHYSS), Mini-M ental State Examination (MMSE) and Geriatric Depression Scale (GDS). P-value less than 0.05 was considered as significant RESULTS: A total of 300 persons were enrolled in the study. The mean age of Parkinson's patients and non-Parkinson's people was 70.34 ± 7.76 and 70.87 ± 7.59 years, respectively. The mean MMSE score in Parkinson's and non-Parkinson's people was 24.80 ± 4.53 and 25.40 ± 3.1, respectively (p = 0.182). The mean GDS score in Parkinson's and non-Parkinson's people was 7.06 ± 4.06 and 4.31 ± 3.47, respectively (p = 0.001). There was a statistically significant relationship between depressive symptoms and cognitive impairments with disease severity (p = 0.022 and p = 0.012, respectively). In addition, variables, such as age and the education level were associated with cognitive impairments (p = 0.001 and p = 0.021, respectively), but these variables were not significantly associated with depressive symptoms (p = 0.843 and p = 0.411, respectively). There was a significant relationship between depressive symptoms and cognitive impairment in Parkinson's patients and the control group (p = 0.001 and p = 0.003, respectively).

CONCLUSIONS

Cognitive impairments and depressive symptoms were significantly associated with an increase in the severity of Parkinson's disease, and also, depressive symptoms in Parkinson's patients was associated with an increase in cognitive impairments.

Beyond PD-MCI: objectively defined subtle cognitive decline predicts future cognitive and functional changes

OBJECTIVE

Cognitive impairment is prevalent among individuals with Parkinson's disease (PD). Effort has been made to identify individuals at risk for cognitive decline and dementia. Objectively-defined subtle cognitive decline (Obj-SCD) is a novel classification that may identify individuals at risk for cognitive decline prior to a diagnosis of mild cognitive impairment (MCI). We examined the utility of Obj-SCD criteria to predict future cognitive decline and difficulties with activities of daily living (ADLs) among individuals with PD.

METHOD

The sample included 483 individuals newly diagnosed with PD. Participants were followed for a five-year span with yearly visits where they completed neuropsychological tests. Participants were categorized as cognitively normal (CN), the newly proposed Obj-SCD, PD-MCI or Parkinson's disease dementia (PDD). Analyses determined if utilization of Obj-SCD criteria predicted subsequent cognitive impairment and difficulties with ADLs.

RESULTS

At baseline, 372 (77%) participants were classified as CN, 40 (8.3%) classified as Obj-SCD, and 71 (14.7%) classified as PD-MCI. Analyses revealed that relative to the CN group, participants classified as Obj-SCD at baseline, were more likely to develop PD-MCI or PDD within 5 years (odds ratio 2.413; 95% confidence interval 1.215-4.792). Furthermore, the Obj-SCD represented an intermediate level of impairment, relative to the CN and PD-MCI groups, on an independent measure of cognition (Montreal Cognitive Assessment) and ADL.

CONCLUSIONS

Findings provide evidence that Obj-SCD criteria can identify individuals at risk for cognitive decline and impairments in ADL. Obj-SCD criteria may identify individuals at risk for cognitive impairment who are not detected by PD-MCI criteria.

Validation of Revised Chinese Version of PD-CRS in Parkinson's Disease Patients

There is a high prevalence of mild cognitive impairment (MCI) and dementia in Parkinson's disease (PD) patients, but a Chinese version of cognitive rating scale that is specific and sensitive to PD patients is still lacking. The aims of this study are to test the reliability and validity of a Chinese version of Parkinson's disease-cognitive rating scale (PD-CRS), establish cutoff scores for diagnosis of Parkinson's disease dementia (PDD) and PD with mild cognitive impairment (PD-MCI), explore cognitive profiles of PD-MCI and PDD, and find cognitive deficits suggesting a transition from PD-MCI to PDD. PD-CRS was revised based on the culture background of Chinese people. Ninety-two PD patients were recruited in three PD centers and were classified into PD with normal cognitive function (PD-NC), PD-MCI, and PDD subgroups according to the cognitive rating scale (CDR). Those PD patients underwent PD-CRS blind assessment by a separate neurologist. The PD-CRS showed a high internal consistency (Cronbach's Alpha = 0.840). Intraclass Correlation coefficient (ICC) of test-retest reliability reached 0.906 (95% CI 0.860–0.935, p < 0.001). ICC of inter-rater reliability was 0.899 (95% CI 0.848–0.933, p < 0.001). PD-CRS had fair concurrent validity with MDRS (ICC = 0.731, 95% CI 0.602–0.816). All the frontal-subcortical items showed significant decrease in PD-MCI compared with the PD-NC group (p ≤ 0.001), but the instrument cortical items did not (confrontation naming p=0.717, copying a clock p=0.620). All the frontal-subcortical and instrumental-cortical functions showed significant decline in PDD compared with the PD-NC group (p ≤ 0.001). The cutoff value for diagnosis of PD-MCI is 80.5 with the sensitivity of 75.7% and the specificity of 75.0%, and for diagnosis of PDD is 73.5 with the sensitivity of 89.2% and the specificity of 98.9%. Revised Chinese version of PD-CRS is a reliable, acceptable, valid, and useful neuropsychological battery for assessing cognition in PD patients.