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

Bidirectional relationship between depression and activities of daily living and longitudinal mediation of cognitive function in patients with Parkinson's disease

Objective

To investigate the bidirectional relationship between depression and activities of daily living (ADL) in Parkinson's disease (PD) patients and explore the mediating role of cognitive function over time.

Methods

Data from 892 PD patients from the Parkinson's Progression Markers Initiative (PPMI) database were included in this study, and depression, cognitive function, and ADL were measured using the Geriatric Depression Scale (GDS-15), Montreal Cognitive Assessment Scale (MoCA), and Unified Parkinson's Disease Rating Scale, Part II (UPDRS II) respectively. The cross-lagged panel model (CLPM) was employed to analyze the reciprocal relationship between depression and ADL. Then, we explored the mediating role of cognitive function in the bidirectional relationship between depression and ADL in patients with PD, and the mediation effect test was carried out using a bias-corrected nonparametric percentile bootstrap approach.

Results

Depression in patients with PD predicted their subsequent ADL (β = 0.079, p < 0.01), and ADL also predicted their subsequent depression (β = 0.069, p < 0.05), In addition, Bootstrap analysis showed that cognitive function played a significant mediating role in prediction of depression to ADL in patients with PD (β = 0.006, p = 0.074, 95%CI = 0.001 ~ 0.014), and cognitive function also played a significant mediating role in prediction of depression to ADL (β = 0.006, p = 0.067, 95%CI = 0.001 ~ 0.013).

Conclusion

There is a bidirectional relationship between depression and ADL in patients with PD. Furthermore, we found that cognitive function mediates the relationship that exists between depression and ADL in patients with PD. Interventions aimed at enhancing cognitive function could potentially lessen the vicious cycle of depression and ADL in PD, thus improving patient quality of life (QOL).

Psychological predictors of incident subjective cognitive complaints in community dwelling older adults

BACKGROUND

Subjective cognitive complaint (SCC) is associated with future cognitive decline and may be a marker for clinical intervention in the progression to dementia. Among the viable predictors of SCC, psychological factors are clinically relevant, non-invasive early indicators of older adults at elevated risk.    This aim of this study is to determine whether psychological symptoms: dysphoria and apathy precede incident SCC in the dementia pathway.

METHODS

Participants (n = 592) enrolled in the Central Control of Mobility in Aging Study were includes in the analyses, with prevalent cases excluded. Apathy and dysphoria scale scores were derived using confirmatory factor analysis of the Geriatric Depressive Scale. Cox regression analyses was used to determine the association between apathy and dysphoria scores and incident SCC.

RESULTS

Over a mean follow up of 1.90 years, 44 individuals (9.26%) developed incident SCC. Baseline apathy scale score was significantly associated with 4-fold increased risk of SCC (HR 4.39, 95%CI: 1.32-14.67), adjusted for cognition but not age and dysphoria scale score. Baseline dysphoria scale score was not associated with increased risk of SCC in adjusted analyses.

CONCLUSION

In this longitudinal analysis of community dwelling older adults, apathy was associated with an increased risk of SCC, when adjusting for cognition but not dysphoria. Finally, this study highlights apathy as an early risk factor, which may precede SCC in the progression to dementia and consequently, may identify a high risk group for clinical screening and intervention.

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.

Stratifying Risk for Cognitive Decline in Older Adult Populations using the Geriatric Depression Scale

Objectives

Late-life psychological symptoms in older adults such as depression and apathy have been increasingly associated with increased risk of cognitive and functional decline. The goal of this study was to conduct a confirmatory factor analysis of the Geriatric Depression Scale (GDS), pooling 3 unique cohorts of older adults to 1) develop a novel measurement model that distinguishes apathy from other domains of depression including dysphoria and cognitive concern and 2) evaluate if the measurement model distinguishes older adult populations with varied risk for cognitive decline.

Methods

We pooled the baseline waves of three older adult cohorts (N=1421). With the aim of partitioning apathy from other constructs that compose the GDS and with a PCA suggesting 3-component solution, we then conducted a confirmatory factor analysis (CFA) using lavaan and less R.

Results

CFA yielded 3 factors: dysphoria, apathy, and cognitive concern. All the dysphoria, apathy, and cognitive concern factors showed acceptable unidimensionality with α=.76, .59, and .54, respectively. The Cognitive Risk Primary Care cohort had significantly higher mean dysphoria, apathy and cognitive concern scales.

Conclusions

This culturally, linguistically, and educationally diverse sample population yielded factors with acceptable reliability and good face validity. This strategy has resulted in a generalizable measurement model to identify people at risk for Alzheimer's disease and related dementia. In particular, the apathy scale score can be used to identify older adults at risk for cognitive and functional decline across research and clinical settings.

Effects of stepped speech rehabilitation and psychological intervention on speech disorders and cognitive function in Parkinson disease patients

To examine the impact of stepwise speech rehabilitation exercise therapy in the treatment of patients with Parkinson speech problems under psychological intervention on clinical results and cognitive functioning. Parkinson speech disorder patients who met the inclusion criteria were selected and divided into a control group and an observation group for training respectively. The control group used conventional nursing methods, including training in orofacial movement, vocalization, pitch, volume and breath control. The observation group used stepwise speech rehabilitation exercise intervention combined with psychotherapy nursing programme. In the statistical analysis, independent sample t-test and chi-square test were used to test the significance of the data processing methods. In the statistical analysis of baseline functional level (P > .05). The difference was not statistically significant. After 7 weeks of training, the mFDA level and speech intelligibility increased in both the observation and control groups. From the situation analysis of "modified drinking test" and the comparison of UPDRS-I scores, it can be seen that dysphagia and Parkinson dysphasia were reduced in both groups after training. The observation group spontaneous speech dimension was greater than the control group by around 0.07 in the aphasia comparison. Both groups displayed an upward trend in their MMSE and Montreal Cognitive Assessment (MoCA) when measuring cognitive function; the evaluation of P300, constructive function, and quality of life revealed this. The observation group P300 potential score was 0.13 points higher than that of the control group. The therapeutic training of stepped speech rehabilitation exercise care combined with psychological intervention has significant nursing effects on patients with Parkinson disease speech disorders, and the patients' cognitive functions have been effectively improved.

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.

Mediation Analyses of the Role of Apathy on Motoric Cognitive Outcomes

Recent literature indicates that apathy is associated with poor cognitive and functional outcomes in older adults, including motoric cognitive risk syndrome (MCR), a predementia syndrome. However, the underlying biological pathway is unknown. The objectives of this study were to (1) examine the cross-sectional associations between inflammatory cytokines (Interleukin 6 (IL-6) and C-Reactive Protein (CRP)) and apathy and (2) explore the direct and indirect relationships of apathy and motoric cognitive outcomes as it relates to important cognitive risk factors. N = 347 older adults (≥65 years old) enrolled in the Central Control of Mobility in Aging Study (CCMA). Linear and logic regression models showed that IL-6, but not CRP was significantly associated with apathy adjusted for age, gender, and years of education (β = 0.037, 95% CI: 0.002-0.072, p = 0.04). Apathy was associated with a slower gait velocity (β = -14.45, 95% CI: -24.89-4.01, p = 0.01). Mediation analyses demonstrated that IL-6 modestly mediates the relationship between apathy and gait velocity, while apathy mediated the relationships between dysphoria and multimorbidity and gait velocity. Overall, our findings indicate that apathy may be an early predictor of motoric cognitive decline. Inflammation plays a modest role, but the underlying biology of apathy warrants further investigation.

Evidence-Informed Approach to De-Prescribing of Atypical Antipsychotics (AAP) in the Management of Behavioral Expressions (BE) in Advanced Neurocognitive Disorders (NCD): Results of a Retrospective Study

The LuBAIR™ Paradigm is a novel approach to ascribe meaning to behavioral expressions in advanced neurocognitive disorders when the reliability of a clinical assessment is limited. The meaning ascribed to each behavioral category was used to identify those which are likely to respond to the use of atypical antipsychotics, in their management. De-prescribing was attempted on patients who qualified to enter this retrospective study. De-prescribing was defined as successful if individuals were completely withdrawn from AAP and remained off them for 60 days, without the re-emergence of behaviors. The LuBAIR™ Inventory was filled on two occasions. The data collected on the second occasion, in the successful and failed de-prescribed groups, were compared in this retrospective study. MANOVA, Chi-Square paired t-test statistical analyses were used to detect the differences in the behavioral categories between the two cohorts. Cohen d was used to measure effect size. Patients who did not have Mis-Identification and Goal-Directed Expressions were more likely to successfully de-prescribe: X2 (1, N = 40) = 29.119 p < 0.0001 and X2 (1, N = 40) = 32.374, p < 0.0001, respectively. Alternatively, the same behavioral categories were more likely to be present in patients who failed de-prescribing: MANOVA and paired t-test (p < 0.0001). Atypical antipsychotics, in their role as an antipsychotic and mood stabilizer, may be used to manage Mis-Identification and Goal-Directed Expressions, respectively.