Greater subjective cognitive decline severity is associated with worse memory performance and lower entorhinal cerebral blood flow in healthy older adults.

OBJECTIVE: Subjective cognitive decline (SCD) is a potential early risk marker for Alzheimer's disease (AD), but its utility may vary across individuals. We investigated the relationship of SCD severity with memory function and cerebral blood flow (CBF) in areas of the middle temporal lobe (MTL) in a cognitively normal and overall healthy sample of older adults. Exploratory analyses examined if the association of SCD severity with memory and MTL CBF was different in those with lower and higher cardiovascular disease (CVD) risk status. METHODS: Fifty-two community-dwelling older adults underwent magnetic resonance imaging, neuropsychological testing, and were administered the Everyday Cognition Scale (ECog) to measure SCD. Regression models investigated whether ECog scores were associated with memory performance and MTL CBF, followed by similar exploratory regressions stratified by CVD risk status (i.e., lower vs higher stroke risk). RESULTS: Higher ECog scores were associated with lower objective memory performance and lower entorhinal cortex CBF after adjusting for demographics and mood. In exploratory stratified analyses, these associations remained significant in the higher stroke risk group only. CONCLUSIONS: Our preliminary findings suggest that SCD severity is associated with cognition and brain markers of preclinical AD in otherwise healthy older adults with overall low CVD burden and that this relationship may be stronger for individuals with higher stroke risk, although larger studies with more diverse samples are needed to confirm these findings. Our results shed light on individual characteristics that may increase the utility of SCD as an early risk marker of cognitive decline.

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.

Differences between episodic and semantic memory in predicting observation-based activities of daily living in mild cognitive impairment and Alzheimer's disease.

Individuals with mild cognitive impairment (MCI) can often progress into Alzheimer's Disease (AD). Research suggests that decline in episodic memory and semantic memory, as well as functional abilities, can be sensitive in predicting disease progression. This study aimed to (a) investigate episodic and semantic memory performance differences between AD and MCI, (b) determine if memory performance predicts observation-based activities of daily living (ADLs), and (c) explore whether semantic memory mediates the relationship between episodic memory and ADLs. Fifty-eight AD, 53 MCI, and 72 healthy control participants were administered the Rey-O, California Verbal Learning Test, Animal Fluency Test, Boston Naming Test, and Direct Assessment of Functional Status (DAFS). The results revealed, first, that AD participants performed significantly lower than the MCI participants across semantic memory and episodic memory tasks, with the exception of the Boston Naming Test. Second, hierarchical-stepwise regression analyses found that semantic memory significantly predicted DAFS orientation, communication, and financial skills in AD, but episodic memory predicted shopping skills. Furthermore, semantic memory significantly predicted DAFS transportation skills in AD and MCI. Third, within the overall sample, semantic memory mediated the relationship between episodic memory and ADLs. Taken together, the findings suggest decline in semantic memory (as measured by confrontational naming and category fluency) and episodic memory (as measured by list and complex visual design learning and recall) may lead to decline in different and specific aspects of functional abilities in AD and MCI.

Self-reported subjective cognitive decline is associated with global cognition in a community sample of Latinos/as/x living in the United States.

INTRODUCTION: Although subjective cognitive decline (SCD) may be an early risk marker of Alzheimer's Disease (AD), research on SCD among Hispanics/Latinos/as/x (henceforth Latinos/as) living in the U.S. is lacking. We investigated if the cross-sectional relationship of self-reported SCD with objective cognition varies as a function of ethnic background (Latinos/as versus Non-Hispanic Whites [NHWs]). Secondary analyses conducted solely within the Latino/a group investigated if informant reported SCD is associated with objective cognition and whether self-reported SCD is related to markers of brain health in a sub-sample of Latinos/as with available MRI data. METHODS: Eighty-three participants (≥60 years of age) without dementia (35 Latinos/as; 48 NHWs) completed the Mattis Dementia Rating Scale (MDRS) and the Subjective Cognitive Decline-Questionnaire (SCD-Q). Additionally, 22 Latino/a informants completed the informant-version of the SCD-Q. Hierarchical regression models investigated if ethnicity moderates the association of MDRS and SCD-Q scores after adjusting for demographics and depressive symptoms. Correlational analyses within the Latino/a group investigated self- and informant-reported associations of SCD-Q scores with objective cognition, and associations of self-reported SCD-Q scores with medial temporal lobe volume and thickness. RESULTS: Latinos/as had lower education and MDRS scores than NHWs. Higher SCD-Q scores were associated with lower MDRS scores only in Latinos/as. Within the Latino/a group, self, but not informant reported SCD was related to objective cognition. Medium to large effect sizes were found whereby higher self-reported SCD was associated with lower entorhinal cortex thickness and left hippocampal volume in Latinos/as. CONCLUSIONS: The association of SCD and concurrent objectively measured global cognition varied by ethnic background and was only significant in Latinos/as. Self-reported SCD may be an indicator of cognitive and brain health in Latinos/as without dementia, prompting clinicians to monitor cognition. Future studies should explore if SCD predicts objective cognitive decline in diverse groups of Latinos/as living in the U.S.

A preliminary model of health regarding sexual and ethnic minority older adults.

Older individuals with sexual/gender minority and minority racial/ethnic identities typically face unique challenges, along with opportunities to overcome these obstacles. Published studies on the difficulties faced by sexual and gender minorities are available; however, research on older adults with both racial/ethnic minority and sexual and gender minority identities is rarer. These individuals must confront various forms of discrimination related to ageism, homophobia and racism. Resilience likely plays a role in the ability to manage and survive multiple challenges and discriminatory experiences, yet targeted research on these populations is lacking. This paper offers a preliminary model that incorporates prevalent threats to these populations' well-being and their deleterious psychosocial correlates, especially, whenever available, the unique challenges that older individuals must face when age, sexual orientation and race/ethnicity intersect. Recommendations are made to optimise the expansion and empirical testing of this preliminary model.

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.

Response inhibition in Veterans with a history of mild traumatic brain injury: The role of self-reported complaints in objective performance.

INTRODUCTION: Although objective deficits in response inhibition (RI) have been detected in civilians with mild traumatic brain injury (mTBI), it remains unclear whether objective RI is worse in military Veterans with mTBI despite the prevalence of self-reported disinhibition. Assessing RI in Veterans is critical due to their unique characteristics, including combat and blast exposure, in addition to the prevalence of psychiatric comorbidity. Therefore, the aims of this study were to (1) examine RI performance in Veterans with mTBI compared to non-mTBI Veterans and (2) compare RI performance in well-defined subgroups of mTBI Veterans with and without self-reported complaints of disinhibition to non-mTBI Veterans. METHOD: 53 mTBI Veterans and 37 non-mTBI Veterans completed a Go/No-Go RI task and measures of self-reported disinhibition (Frontal Systems Behavior Scale) and psychiatric symptoms. ANCOVAs covarying for mood and demographics compared RI performances of the non-mTBI Veterans to (1) the total sample of mTBI Veterans (n= 53) and to (2) mTBI Veterans with elevated (t-score ≥ 60; mTBI-SubjDis; n= 23) and low (t-score < 60; mTBI-NoSubjDis; n= 30) levels of self-reported disinhibition. RESULTS: There were no significant differences in RI between the mTBI group as a whole and the non-mTBI Veterans group. However, when Veterans with mTBI were divided into groups by clinically-significant concern about their disinhibition, the mTBI-SubjDis group demonstrated significantly worse RI than the mTBI-NoSubjDis and non-mTBI Veteran groups. No significant differences in RI performance were observed between the mTBI-NoSubjDis and non-mTBI Veteran groups. CONCLUSIONS: Results indicate that mTBI Veterans with elevated levels of self-reported disinhibition show diminished performance on objective measures of RI, independent of mood. Findings highlight the unique contribution of subjective complaints on executive functioning in mTBI, and they underscore the importance of assessing cognitive complaints in order to identify those most at risk for poor-long term outcomes.

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).

Inaccuracy between subjective reports and objective measures of sleep duration and clinical correlates in bipolar disorder.

BACKGROUND: Sleep disturbances are common in bipolar disorder (BD) and are often assessed by self-report at clinic visits over the course of BD treatment. Self-report may be subject to recall bias based upon current mood/affect states. This study sought to identify the degree of inaccuracy between subjective and objective measures of sleep duration in those with and without BD, and to assess the demographic and clinical correlates of this inaccuracy. METHODS: Thirty-one individuals with BD and 54 healthy control (HC) participants reported on the number of hours slept a night over the past month and subsequently completed up to 14 days/nights of wrist actigraphy which provided an objective measure of sleep duration. We compared the subjective rating to the average of all nights of objective sleep duration, and correlated the magnitude of inaccuracy with demographic and clinical characteristics in the BD and HC groups. RESULTS: On average, both BD and HC groups overestimated their sleep, and there were no differences in inaccuracy between groups. In the BD group, greater inaccuracy was associated with lower functioning, even after controlling individually for objective and subjective sleep measures. LIMITATIONS: Cross-sectional study, only focus on sleep duration, and less severe bipolar symptoms of sample. CONCLUSIONS: Inaccuracy in reports of sleep duration was associated with lower functioning among BD patients. Better identifying discrepancies in reports of sleep duration in clinical practice could help in more efficient monitoring and management of BD symptoms.