The relationship between objective and subjective executive function in Parkinson's disease.

INTRODUCTION: Difficulties in executive functioning (EF) are common in PD; however, the relationship between subjective and objective EF is unclear. Understanding this relationship could help guide clinical EF assessment. This study examined the relationship between subjective self-reported EF (SEF) and objective EF (OEF) and predictors of SEF-OEF discrepancies in PD. METHOD: One-hundred and sixteen non-demented PD participants completed measures of OEF (i.e. problem-solving, cognitive flexibility, inhibition, and working memory) and SEF (Frontal Systems Behavior Scale-Self Executive Dysfunction Subscale). Pearson bivariate correlations and linear regressions were performed to examine the relationship between SEF and OEF and the non-motor symptoms (e.g. mood, fatigue), demographic, and PD characteristic (e.g. MCI status) predictors of discrepancies between OEF and SEF (|OEF minus SEF scores|). Correlates of under-, over-, and accurate-reporting were also explored. RESULTS: Greater SEF complaints and worse OEF were significantly associated (ß =.200, p = .009) and 64% of participants accurately identified their level of OEF abilities. Fewer years of education and greater symptoms of depression, anxiety, and fatigue significantly correlated with greater discrepancies between OEF and SEF. Fatigue was the best predictor of EF discrepancy in the overall sample (ß = .281, p = .022). Exploratory analyses revealed apathy and fatigue associated with greater under-reporting, while anxiety associated with greater over-reporting. CONCLUSIONS: SEF and OEF are significantly related in PD. Approximately 64% of non-demented persons with PD accurately reported their EF skill level, while 28% under-reported and 8% over-reported. SEF-OEF discrepancies were predicted by fatigue in the overall sample. Preliminary evidence suggests reduced apathy and fatigue symptoms relate to more under-reporting, while anxiety relates to greater over-reporting. Given the prevalence of these non-motor symptoms in PD, it is important to carefully consider them when assessing EF in PD.

Perception of Fragmented Letters by Patients With Pathologically Confirmed Dementia With Lewy Bodies or Alzheimer Disease.

BACKGROUND AND OBJECTIVE: Patients with dementia with Lewy bodies perform worse than those with Alzheimer disease (AD) on tests of visual perception, but the clinical utility of these tests remains unknown because studies often had clinically diagnosed groups that may inadvertently cross-contaminate Lewy body disease (LBD) with pure AD pathology, used experimental tests not easily adaptable for clinical use, and had no way to examine relationships between the severity of LBD pathology and degree of cognitive impairment. Therefore, we sought to determine whether performance on a widely used clinical test of visuoperceptual ability effectively differentiates between patients with autopsy-confirmed LBD or AD and correlates with the severity of LBD pathology. METHODS: Patients with mild to moderate dementia (n = 42) and cognitively healthy controls (n = 22) performed a Fragmented Letters Test in which they identified letters of the alphabet that were randomly visually degraded by 70% and additional visuospatial and episodic memory tests. At autopsy, dementia cases were confirmed to have LBD (n = 19), all with concomitant AD, or only AD (n = 23). Severity of α-synuclein pathology in the hippocampus and neocortex was rated on an ordinal scale. RESULTS: Patients with LBD performed worse than those with AD (B = -2.80 ± 0.91, p = 0.009) and healthy controls (B = -3.34 ± 1.09, p = 0.01) on the Fragmented Letters Test after adjustment for age, sex, education, Mini-Mental State Examination score, and ability to name intact letters. Patients with AD did not differ from controls (B = -0.55 ± 1.08, p = 0.87). The test effectively distinguished between patients with LBD or AD with 73% sensitivity and 87% specificity, and the area under the curve in receiver operating characteristic analyses was 0.85 (95% CI 0.72-0.95), higher than for standard tests of visuospatial ability (Block Design; 0.72; CI 0.35-0.75) or memory (California Verbal Learning Test, trials 1-5; 0.55; CI 0.57-0.88). Fragmented Letters Test scores were negatively correlated with LBD pathology density ratings in hippocampus and neocortical regions (Spearman rs = -0.53 to -0.69). DISCUSSION: Fragmented Letters Test performance can effectively differentiate patients with LBD pathology from those with only AD pathology at a mild to moderate stage of dementia, even when LBD occurs with significant concomitant AD pathology, and may also be useful for gauging the severity of cortical α-synuclein pathology in those with LBD.

Prospective predictors of care partner burden and depression in Parkinson's disease.

OBJECTIVES: Care partners who provide informal care to individuals with Parkinson's disease (PD) report higher levels of burden and depression; however, longitudinal research on these symptoms is scarce. The current study assessed changes in care partner burden and depression, and patient and care partner predictors of these symptoms over time. Such knowledge may provide important information for assessment and treatment of depression and burden in care partners of individuals with PD. RESEARCH DESIGN AND METHODS: Participants were 88 PD patients without dementia and their self-identified care partner (n = 88). Care partners completed the Geriatric Depression Scale and Zarit Burden Interview. PD participants completed mood questionnaires and a motor exam at baseline and 2 year follow-up. Relationships among care partner burden and depression over time with patient and care partner predictors (i.e., demographic, mood, and disease characteristics) were assessed using correlations and regression analyses. RESULTS: Care partner burden and depression significantly increased over an approximate 2 year period. Greater baseline disease severity predicted worsening of care partner burden (p = 0.028), while baseline patient depression predicted worsening of care partner depression (p = 0.002). CONCLUSIONS: Results highlight differential impacts of specific PD symptoms on worsening care partner burden compared to depression; increased PD disease severity predicts increased burden, while patient mood predicts worsening of depression over time. Targeting PD disease severity and mood symptoms may prevent the progression of care partner burden and depression.

Changes in Self- and Informant-Reported Frontal Behaviors in Parkinson's Disease: A Longitudinal Study.

OBJECTIVE: Frontal behaviors (i.e., executive dysfunction, disinhibition, apathy) are common in Parkinson's disease (PD). However, it is unclear if patient and informant reports of patient frontal behaviors are in agreement over time. METHOD: Sixty-two PD patients without dementia and their informants (87% spouses/partners) completed the self- and informant-versions of the Frontal Systems Behavior Scale at baseline and 2-year follow-up. Dyad ratings were compared and predictors of behavior ratings were examined. RESULTS: Patient and informant reports at baseline and follow-up were in agreement, with significant increases in overall frontal behaviors, executive dysfunction, and apathy. Higher levels of baseline patient depression and caregiver burden predicted decrements in patient-reported executive function; worse patient cognition at baseline predicted worsening apathy as rated by informants. CONCLUSIONS: PD patients and their informants are concordant in their ratings of worsening frontal behaviors over time. Targeting patient depression, cognition, and caregiver burden may improve decrements in frontal behaviors (executive dysfunction and apathy) in PD.

Association of Stress-Health Factors among Parkinson's Disease Patient/Caregiving-Partner Dyads.

OBJECTIVE: Few studies have explored the shared effects of Parkinson's disease (PD) within patient/caregiver dyads. To fill this gap, we compared stress-health outcomes of patients with those of caregiving-partners, examined individual stress-health associations, and explored stress-health associations within dyads. METHOD: A total of 18 PD patient/caregiving-partner dyads (N = 36) reported on disease-specific distress, anxiety, quality of life (QOL), and provided saliva samples for cortisol assessment. This cross-sectional, secondary analysis of a prospective pilot study used Actor-Partner Interdependence Models to test aims. RESULTS: Patients reported greater anxiety, poorer QOL, and demonstrated flatter cortisol slopes and higher mean bedtime cortisol compared to caregiving-partners. Both patients and caregiving-partners with greater anxiety had elevated bedtime cortisol and poorer QOL. Greater disease-specific distress in an individual was associated with higher diurnal mean cortisol in their partner. CONCLUSIONS: Findings highlight the potential for psychosocial interventions at the dyadic level to reduce shared burden and promote coping among PD patient/caregiving-partner dyads.

REM Sleep Behavior Disorder in Parkinson's Disease: Change in Cognitive, Psychiatric, and Functional Outcomes from Baseline to 16-47-Month Follow-Up.

OBJECTIVE: Rapid Eye Movement Sleep Behavior Disorder (RBD) is common in Parkinson's Disease (PD) and is associated with cognitive impairment; however, the majority of the evidence on the impact of RBD on multidomain cognitive batteries in PD is cross-sectional. This study evaluated the longitudinal impact of probable RBD (pRBD) on cognitive, psychiatric, and functional outcomes in people with PD. METHOD: Case-control study. A total of 65 people with PD completed the study protocol at baseline and 16-to-47-month follow-up. Participants were classified as pRBD+ (n = 25) or pRBD- (n = 40) based on an established cutoff of 6 on the RBD Sleep Questionnaire (RBDSQ). Participants also completed a) comprehensive cognitive testing, b) self-report measures of depression, anxiety, and apathy, and c) performance-based and other-report forms of instrumental activities of daily living. RESULTS: Baseline mean age was 67.8 (SD = 8.1; range = 45-86) and baseline mean years of education was 16.4 (SD = 2.1; range = 12-20). The two groups did not differ on measured demographic characteristics. Baseline mean T-scores for cognitive tests were in the average range (46-55). Hierarchical linear models tested group differences in cognitive and functional decline from baseline to follow-up, controlling for appropriate demographic and psychiatric variables. Compared to the pRBD- group, pRBD+ participants showed greater decline in attention/working memory (r = -0.31; p = 0.01) and UPSA financial skills (r = -0.31; p = 0.01). No other group differences approached significance. CONCLUSIONS: RBD may differentially affect attention/working memory and financial abilities in PD. Results underscore the importance of regular RBD screening in older adults with PD in order to triage symptomatic patients to appropriate cognitive and medical interventions.

Thalamic volume mediates associations between cardiorespiratory fitness (VO2max) and cognition in Parkinson's disease.

INTRODUCTION: Cognitive deficits occur in Parkinson's disease (PD). Cardiorespiratory fitness (CRF) is associated with better cognitive performance in aging especially in executive function (EF) and memory. The association between CRF and cognitive performance is understudied in people with PD. Brain structures underlying associations also remains unknown. This cross-sectional study examined the associations between CRF and cognitive performance in PD. We also examined associations between CRF and brain structures impacted in PD. Mediation analysis were conducted to examine whether brain structures impacted in PD mediate putative associations between CRF and cognitive performance. METHODS: Individuals with PD (N = 33) underwent magnetic resonance imaging (MRI), CRF evaluation (estimated VO2max), and neuropsychological assessment. Composite cognitive scores of episodic memory, EF, attention, language, and visuospatial functioning were generated. Structural equation models were constructed to examine whether MRI volume estimates (thalamus and pallidum) mediated associations between CRF and cognitive performance (adjusting for age, education, PD disease duration, sex, MDS-UPDRS motor score, and total intracranial volume). RESULTS: Higher CRF was associated with better episodic memory (Standardized ß = 0.391; p = 0.008), EF (Standardized ß = 0.324; p = 0.025), and visuospatial performance (Standardized ß = 0.570; p = 0.005). Higher CRF was associated with larger thalamic (Standardized ß = 0.722; p = 0.004) and pallidum (Standardized ß = 0.635; p = 0.004) volumes. Thalamic volume mediated the association between higher CRF and better EF (Indirect effect = 0.309) and episodic memory (Indirect effect = 0.209) performance (p < 0.05). The pallidum did not significantly mediate associations between CRF and cognitive outcomes. CONCLUSION: The thalamus plays an important role in the association between CRF and both EF and episodic memory in PD.

Medication Management Performance in Parkinson's Disease: Examination of Process Errors.

OBJECTIVE: Individuals with Parkinson's disease (PD) are at risk for increased medication mismanagement, which can lead to worse clinical outcomes. However, the nature of the errors (i.e., undertaking or overtaking medications) contributing to mismanagement and their relationship to cognition in PD is unknown. Therefore, this study sought to examine errors committed on the Medication Management Ability Assessment (MMAA) between PD participants with normal cognition (PD-NC) or mild cognitive impairment (PD-MCI) relative to healthy adults (HA). METHOD: HA (n = 74), PD-NC (n = 102), and PD-MCI (n = 45) participants were administered the MMAA to assess undertaking, overtaking, and overall errors as well as overall performance (total score). Additionally, participants were administered a comprehensive neuropsychological battery from which cognitive composites of Attention, Learning, Memory, Language, Visuospatial, and Executive Functioning were derived. RESULTS: Separate negative binomial regression analyses indicated the PD-MCI group performed significantly worse overall on the MMAA (total score) and committed more undertaking and overall errors relative to HA and PD-NC. In the PD-MCI group, poorer MMAA performance was associated with worse delayed memory performance, whereas cognitive performance was not related to MMAA in HA or PC-NC. CONCLUSION: Compared to PD and healthy adults with normal cognition, PD-MCI patients exhibited greater difficulty with medication management, particularly with undertaking medications. Poorer medication management in PD-MCI was associated with worse delayed recall. Thus, PD-MCI patients experiencing memory problems may require additional assistance with their medications. Findings have clinical relevance suggesting that objective measures of medication errors may assist clinicians in identifying PD patients needing adherence strategies.

Delineation of Apathy Subgroups in Parkinson's Disease: Differences in Clinical Presentation, Functional Ability, Health-related Quality of Life, and Caregiver Burden.

BACKGROUND: Apathy is a prevalent, multidimensional neuropsychiatric condition in Parkinson's disease (PD). Several authors have proposed apathy subtypes in PD, but no study has examined the classification of PD patients into distinct apathy subtypes, nor has any study examined the clinical utility of doing so. OBJECTIVES: The current study used a data-driven approach to explore the existence and associated clinical characteristics of apathy subtypes in PD. METHOD: The Apathy Scale (AS) was administered to 157 non-demented individuals with PD. Participants were classified into apathy subgroups through cluster analysis. Differences among apathy subtypes on external clinical indicators were explored across apathy subgroups. RESULTS: Individuals with PD were classified into three subgroups: a Non-Apathetic group with low levels of apathy symptoms, a Low Interest/Energy group, characterized by elevated symptoms of low interest/energy and minimal low initiation/emotional indifference symptoms, and a Low Initiation group, characterized by an absence of low interest/energy symptoms and elevated levels of low initiation/emotional indifference symptoms. Both Low Interest/Energy and Low Initiation groups exhibited worse depression, fatigue, anxiety, health-related quality of life, and caregiver burden than the Non-Apathetic subgroup. The Low Initiation group exhibited worse overall cognition, emotional well-being, state anxiety, communicative ability, and functional ability than the Low Interest/Energy group. Importantly, disease-related characteristics did not differ across apathy symptom subgroups. CONCLUSIONS: Non-demented PD patients can be separated into distinct apathy symptom subgroups, which are differentially associated with important clinical variables. Apathy subgroup membership may reflect disruption to different neural systems independent of disease progression.

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.

REM Sleep Behavior Disorder in Parkinson's Disease: Effects on Cognitive, Psychiatric, and Functional outcomes.

OBJECTIVE: Rapid eye movement sleep behavior disorder (RBD) affects 33-46% of patients with Parkinson's disease (PD) and may be a risk factor for neuropsychological and functional deficits. However, the role of RBD on neuropsychological functioning in PD has yet to be fully determined. We, therefore, examined differences in neurocognitive performance, functional capacity, and psychiatric symptoms among nondemented PD patients with probable RBD (PD/pRBD+) and without (PD/pRBD-), and healthy comparison participants (HC). METHODS: Totally, 172 participants (58 PD/pRBD+; 65 PD/pRBD-; 49 HC) completed an RBD sleep questionnaire, psychiatric/clinical questionnaires, performance-based and self-reported functional capacity measures, and underwent a comprehensive neuropsychological battery assessing attention/working memory, language, visuospatial function, verbal and visual learning and memory, and executive function. RESULTS: Controlling for psychiatric symptom severity, the PD/pRBD+ group had poorer executive functioning and learning performance than the PD/pRBD- group and poorer neuropsychological functioning across all individual cognitive domains than the HCs. In contrast, PD/pRBD- patients had significantly lower scores than HCs only in the language domain. Moreover, PD/pRBD+ patients demonstrated significantly poorer medication management skills compared to HCs. Both PD groups reported greater depressive and anxiety severity compared to HCs; PD/pRBD+ group also endorsed greater severity of apathy compared to HCs. CONCLUSIONS: The presence of pRBD is associated with poorer neuropsychological functioning in PD such that PD patients with pRBD have poorer cognitive, functional, and emotional outcomes compared to HC participants and/or PD patients without pRBD. Our findings underscore the importance of RBD assessment for improved detection and treatment of neuropsychological deficits (e.g., targeted cognitive interventions).

Cognitive decline profiles differ in Parkinson disease dementia and dementia with Lewy bodies.

OBJECTIVE: To examine whether domain-specific patterns of cognitive impairment and trajectories of decline differed in patients with clinically diagnosed Parkinson disease dementia (PDD) (N = 29) and autopsy-confirmed dementia with Lewy bodies (DLB) (N = 58) or Alzheimer disease (AD) (N = 174) and to determine the impact of pooling patients with PDD and DLB in clinical trials targeting cognition. METHODS: Patients were matched on demographics and level of global cognitive impairment. Patterns of cross-sectional performance and longitudinal decline were examined in 4 cognitive domains: Visuospatial, Memory, Executive, and Language. Power analyses were performed to determine the numbers of participants needed to adequately power a hypothetical clinical trial to slow cognitive decline in pure PDD, pure DLB, or a mixed PDD/DLB group. RESULTS: Both DLB and PDD were more impaired and declined more rapidly than AD in the Visuospatial domain. Patients with PDD exhibited the most impairment and fastest decline in Executive, although patients with DLB also declined faster than AD. Memory was more impaired in AD than DLB and in both compared with PDD; however, all 3 groups declined at comparable rates. In contrast, PDD declined at a slower rate on Language measures than DLB or AD. Power analyses suggest that Visuospatial and Executive outcome measures would be most sensitive in PDD, but Memory and Language in DLB. CONCLUSION: DLB and PDD differ from each other, and from AD, in a cognitive domain-specific manner. As such, different outcome measures may be most sensitive to detecting changes in DLB vs PDD, suggesting that the 2 should be analyzed separately in clinical trials.

Mild cognitive impairment, psychiatric symptoms, and executive functioning in patients with Parkinson's disease.

OBJECTIVE: Mild cognitive impairment (MCI) and psychiatric symptoms (anxiety, depression, and apathy) are common in Parkinson's disease (PD). While studies have supported the association between psychiatric symptoms and cognitive performance in PD, it is unclear if the magnitude of link between psychiatric symptoms and cognitive health is stronger by MCI status. The purpose of this study was to examine the association between cognitive performance and psychiatric symptoms in PD and whether MCI status moderates this association. METHODS/DESIGN: Participants (N = 187) completed a comprehensive neuropsychological assessment that included measures of attention, language, executive function (EF), visuospatial ability, episodic memory, and psychiatric symptoms. Participants were classified as PD-MCI (N = 73) or PD-normal cognition (NC; N = 114). Linear regression analyses were conducted to examine the association between psychiatric symptoms and cognitive performance and the moderating effect of PD-MCI status. RESULTS: There were no differences in mean psychiatric symptoms between PD-MCI and PD-NC. Psychiatric symptoms were predominantly associated with worse EF. The magnitude of the association between anxiety and worse EF was larger in participants with PD-MCI compared with PD-NC. A multivariable regression analysis examining the independent contributions of each symptom demonstrated the most robust association between EF and anxiety. CONCLUSIONS: Symptoms of anxiety, depression, and apathy are associated with worse executive functioning in individuals with PD. PD-MCI may be important in moderating the association between cognitive performance, specifically anxiety, and EF. Factors that promote cognitive resilience may serve as key therapeutic modalities in managing neuropsychiatric symptoms in PD.

Utility of the D-KEFS Color Word Interference Test as an embedded measure of performance validity.

Objective: The D-KEFS Color Word Interference Test (CWIT) is among the most commonly administered measures of verbally mediated processing speed and executive functioning. Previous research suggests that this test may also be sensitive to performance invalidity. We sought to develop new embedded measures of performance invalidity based on multi-condition performance on the CWIT and to evaluate previously proposed embedded measures for performance invalidity on this test.Method: Newly developed and previously proposed embedded measures were evaluated in three samples: a traumatic brain injury (TBI) sample (N = 224) classified into psychometrically-defined performance-valid and performance-invalid subgroups; the D-KEFS normative sample (N = 1,735); and a Parkinson's disease sample (N = 166). To explore the resilience of CWIT cutoffs to the effects of age and neurocognitive impairment, the D-KEFS normative sample was stratified into age groups of 8-19, 20-69, and 70-89 and the Parkinson's disease sample into normal cognition, mild cognitive impairment, and dementia groups.Results: Our newly developed embedded measures derived from within the TBI sample were largely resilient to the effects of age and neurocognitive impairment other than dementia. Overall, a cutoff of ≤18 on the sum of age-corrected scaled scores on all four conditions exhibited the strongest classification accuracy. In contrast, previously proposed cutoffs (Erdodi et al., 2018) produced unacceptable false-positive rates within the TBI sample and generally a high rate of potential false positives in the normative age and clinical groups.Conclusion: Scoring ≤18 on the sum of all conditions on the CWIT appears to be an optimal cutoff for performance invalidity detection in non-demented samples.

Recall and Recognition Discriminability in Parkinson's Disease and Huntington's Disease.

BACKGROUND: Parkinson's disease (PD) and Huntington's disease (HD) are two neurodegenerative diseases affecting frontal-striatal function and memory ability. Studies using the original California Verbal Learning Test (CVLT) to examine recall and recognition abilities between these groups have produced mixed findings. Some found that individuals with HD demonstrate worse recall and recognition than those with PD, whereas others reported comparable performance. OBJECTIVE: We utilized multiple indices of recall and recognition discriminability, provided by the second and third editions of the CVLT (CVLT-II and CVLT-3, respectively), that allow for a more thorough assessment of more nuanced aspects of verbal memory function. METHODS: We examined differences between individuals with PD (n = 72) and those with HD (n = 77) on CVLT-II indices of recall discriminability (immediate, short delay free and cued, long delay free and cued) and recognition discriminability (total, source, semantic, and novel) using standardized scores while controlling for education and Dementia Rating Scale-2 scores. RESULTS: The HD group performed significantly worse than the PD group on all measures of recall and recognition discriminability (ps < 0.05), and group differences were associated with large Cohen's d effect sizes. CONCLUSIONS: Our findings suggest that individuals with HD are more impaired than individuals with PD in more nuanced aspects of recall and recognition memory function. These CVLT indices yield more thorough assessments of recall and recognition memory function and have the potential to improve efforts to characterize and distinguish profiles of memory loss in different neurodegenerative populations, including PD and HD.

Factor Analysis of the Apathy Scale in Parkinson's Disease.

BACKGROUND: The Apathy Scale (AS), a popular measure of apathy in Parkinson's disease (PD), has been somewhat limited for failing to characterize dimensions of apathy, such as those involving cognitive, behavioral, and emotional apathy symptoms. This study sought to determine whether factors consistent with these apathy dimensions in PD could be identified on the AS, examine the associations between these factors and disease-related characteristics, and compare PD patients and healthy control (HCs) on identified factors. METHODS: Confirmatory (CFA) and exploratory factor analysis (EFA) were conducted on AS scores of 157 nondemented PD patients to identify AS factors. These factors were then correlated with important disease-related characteristics, and PD and HC participants were compared across these factors. RESULTS: Previously proposed AS models failed to achieve an adequate fit in CFA. A subsequent EFA revealed two factors on the AS reflecting joint cognitive-behavioral aspects of apathy (Motivation-Interest-Energy) and emotional apathy symptoms (Indifference). Both factors were associated with anxiety, depression, health-related quality of life, and independent activities of daily living, with Indifference associated more with the latter. In addition, only the Indifference factor was associated with cognitive functioning. PD patients reported higher levels of symptoms than HCs on both factors, with the group difference slightly larger on the Motivation-Interest-Energy factor. CONCLUSION: The AS can be decomposed into two factors reflecting Motivation-Interest-Energy and Indifference symptoms. These factors are differentially associated with clinical variables, including cognition and independent activities of daily living, indicating the importance of evaluating apathy from a multidimensional perspective.

The role of dispositional mindfulness in a stress-health pathway among Parkinson's disease patients and caregiving partners.

PURPOSE: Parkinson's disease (PD) patients and their caregivers experience significant distress that impacts physical, emotional and social functioning in the patient, and in turn, has a significant impact on the caregiver. Lower levels of stress have been associated with a better prognosis in PD. The quality of dispositional mindfulness-innate present moment, non-judgmental awareness-has consistently been associated with less perceived stress, greater well-being, and better physical health in both clinical and healthy populations. To date, associations of mindfulness with distress, depression, sleep problems, and other variables that define health-related quality of life have not been examined in the context of PD patient/caregiver dyads. METHODS: We investigated the impact of dispositional mindfulness in a stress-health model among eighteen dyads consisting of PD patients and their caregivers. RESULTS: Multilevel linear modeling (actor-partner interdependence models) revealed significant associations between dispositional mindfulness and stress appraisal, interpersonal support, depressive symptoms, sleep, and health-related quality of life (HRQOL) within both dyadic partners. As expected, results demonstrated significant associations of distress with interpersonal support, depressive symptoms, sleep and HRQOL for both PD patients and caregivers. CONCLUSIONS: Dispositional mindfulness was associated with reduced distress and its downstream clinical consequences. These results support an ameliorative role for dispositional mindfulness among PD patients and caregivers, as a protective factor against psychosocial burdens imposed on couples related to disease and caregiving. Findings suggest future studies should explore mindfulness training as a therapeutic option.

Collectivism Is Associated With Greater Neurocognitive Fluency in Older Adults.

Neuropsychological research has been limited in the representation of cultural diversity due to various issues, raising questions regarding the applicability of findings to diverse populations. Nonetheless, culture-dependent differences in fundamental psychological processes have been demonstrated. One of the most basic of these, self-construal (individualism, collectivism), is central to how many other differences are interpreted. Self-construals may have possible consequences on social interactions, emotions, motivation, and cognition. This study aimed to evaluate the impact of self-construal on neurocognitive functions in older adults. A total of 86 community-dwelling older adults 60 years and older were assessed with three common self-report measures of self-construal along individualism and collectivism (IC). A cognitive battery was administered to assess verbal and non-verbal fluency abilities. Latent profile analysis (LPA) was used to categorize individuals according to IC, and one-way analyses of covariance (ANCOVA), including relevant covariates (e.g., ethnicity, gender, linguistic abilities), were used to compare neurocognitive functions between individualists and collectivists. Collectivists outperformed individualists on left frontally-mediated measures of verbal fluency (action, phonemic) after controlling for relevant covariates, F (1,77) = 6.942, p = 0.010, η 2 = 0.061. Groups did not differ on semantic fluency, non-verbal fluency, or attention/working memory (all ps > 0.05). These findings suggest a cognitive advantage in collectivists for verbal processing speed with an additional contribution of left frontal processes involved in lexicosemantic retrieval. Self-construal may provide a meaningful descriptor for diverse samples in neuropsychological research and may help explain other cross-cultural differences.

Worse cognitive performance predicts increased anxiety and depressive symptoms in patients with Parkinson's disease: A bidirectional analysis.

OBJECTIVE: Symptoms of anxiety, depression commonly co-occur with cognitive decline in patients with Parkinson's disease (PD). The directionality of this association is unclear, however, in that poor cognitive performance may lead to increased symptoms of anxiety and depression or higher anxiety and depressive symptoms may lead to cognitive decline. The purpose of this study was to elucidate the directionality of the association between symptoms of anxiety and depression with cognitive performance in newly diagnosed patients with PD. METHOD: Longitudinal data from 362 nondemented participants from the Parkinson's Progression Markers Initiative (PPMI) were examined. Participants completed as many as five assessments of anxiety symptoms, depressive symptoms, and cognitive performance over a 4-year period. Bivariate dual change score models were fit to examine the dynamic association between level and change of anxiety and depressive symptoms with level and change in cognitive performance. RESULTS: Across all cognitive domains, worse performance was associated with subsequently higher state anxiety, trait anxiety, and depressive symptoms. The reverse direction was not significant as higher state anxiety, trait anxiety, and depressive symptoms were not associated with subsequent declines in cognitive performance. CONCLUSIONS: Poorer cognitive performance, across all cognitive domains, was a risk factor for increased symptoms of anxiety and depression a year later. No support was present for the alternative hypothesis that anxiety and depression are associated with subsequent cognitive decline. Clinical implications include the importance of psychoeducation, as well as assessing and monitoring anxiety and depression in patients with PD with poor cognitive performance. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Medication Management Capacity and Its Neurocognitive Correlates in Huntington's Disease.

OBJECTIVE: Although medication management is a necessary daily activity for individuals with Huntington's disease (HD), medication management abilities and their relation to cognitive functioning have not been evaluated. METHOD: Twenty individuals with HD and 20 healthy adults (HA) completed the Medication Management Abilities Assessment (MMAA). Individuals with HD also completed a self-report medication management measure and neuropsychological tests assessing executive function, retrospective memory, and prospective memory. RESULTS: Individuals with HD performed significantly poorer and made more undertaking errors on the MMAA as compared to HA. No group differences were found in overtaking errors. In the HD group, significant associations were found between undertaking errors and perceived medication management ability as well as between MMAA task performance and measures assessing prospective memory and executive functions. CONCLUSIONS: Medication management capacity was negatively affected in individuals with HD and may be associated with difficulty remembering to take medications in the future.