Relationship between neuropsychiatric symptoms and cognitive functions in patients with cognitive impairment

Impact of dual sensory impairment on cognition in older Chinese adults: a moderated chain-mediated effect

Objective

Although sensory impairment has been identified as a risk factor for cognitive decline, little is known about the underlying mechanisms that connect dual sensory impairment to cognitive ability. This research used a moderated chain-mediated model to investigate the underlying mechanisms behind the association between dual sensory impairment and cognitive ability.

Methods

People aged 60 years and older from seven medical institutions, three communities, and five nursing homes in Zunyi city, Guizhou Province, were selected for the study from October 2022 to September 2023 via convenience sampling. Data on demographic characteristics, self-reported hearing and vision loss, and Self-Rating Anxiety Scale (SAS), 15-item Geriatric Depression Scale (GAD-15), Frailty Scale (FRAIL), and Mini-Mental State Examination (MMSE) scores were collected. A moderated chain mediator was used to analyze the underlying mechanisms and pathways of the relationships among anxiety, depression, and cognitive ability in individuals with dual sensory impairment, as well as the moderating role of frailty in this connection.

Results

A total of 7,021 older adults were included, 3,598 (51.25%) of whom were male, with a mean age of 72.01 ± 7.17 years. Dual sensory impairment had a significant direct effect on cognitive ability, with an effect size of -3.134, followed by anxiety and depression, which not only independently mediated the relationship between dual sensory impairment and cognitive ability but also jointly had a chain mediation effect, with mediation effect sizes of -0.766 and -0.182, respectively, and a chain mediation effect size of -0.257. In addition, the interaction effect of dual sensory impairment and frailty was significantly predictive of cognitive ability (effect value = -0.575, p < 0.001).

Conclusion

The mechanisms of action between dual sensory impairment, anxiety, depression, cognitive performance, and frailty are shown in this study. This finding also implies that therapies for psychological issues, frailty, and sensory functioning in older adults can preserve their cognitive ability.

Neuropsychology of Alzheimer's disease: From preclinical phase to dementia

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by significant cognitive and functional decline, initially presenting with episodic memory impairment. A thorough neuropsychological assessment is essential for AD diagnosis, particularly in the early stages in which interventions may be more effective. This paper reviews the neuropsychology of Alzheimer's disease, highlighting the cognitive progression of the disease. In the typical forms of AD, episodic memory appears to be the first and foremost affected cognitive domain. As AD progresses, cognitive impairments extend beyond memory to affect various domains such as attention, executive functions, language, and visuospatial abilities. Neuropsychiatric issues, such as depression and anxiety, which often accompany cognitive decline, are also common, especially at the advanced stages of the disease. While episodic memory impairment is the earliest and most prominent feature in typical AD cases, comprehensive assessments, including social cognition and neuropsychiatric evaluations, are crucial for accurate diagnosis and treatment planning.

Associations of neurocognitive and neuropsychiatric patterns with brain structural biomarkers and dementia risk: A latent class analysis

BACKGROUND

Neurocognitive and neuropsychiatric symptoms are essential clinical manifestations of age-related cognitive impairment, yet their patterns of co-existence remain unclear through the cognitive continuum.

OBJECTIVE

To examine the associations of person-centered cluster-derived patterns, based on a comprehensive collection of domain-specific cognitive and neuropsychiatric assessments, with neuroimaging markers and dementia risk.

METHODS

641 participants were included in the analysis from memory clinics in Singapore. Latent class analysis was applied to define clusters of individuals with different clinical patterns. The associations between identified clinical groups with neuroimaging markers of cerebrovascular diseases and neurodegeneration were analyzed using logistic regression models. Cox proportional hazard models were applied for incident dementia.

RESULTS

Three latent classes differing in neurocognitive and neuropsychiatric impairment were identified (Class 1 "memory impairment only"; Class 2 "global cognitive impairment"; Class 3 "global cognitive and neuropsychiatric impairment"). Compared with Class 1, Class 2 and 3 were associated with smaller brain volumes, moderate-to-severe cortical atrophy and medial temporal lobe atrophy, and the presence of all cerebrovascular lesions. Moreover, compared with Class 2, Class 3 had smaller brain volumes, moderate-to-severe cortical atrophy and presence of intracranial stenosis. Additionally, compared to Class 1, Class 2 (hazard ratio [HR] = 3.84, 95%CI 2.11-7.00), and Class 3 (HR = 6.92, 95%CI 2.84-16.83) showed an increased risk of incident dementia.

CONCLUSIONS

Participants characterized by multi-domain cognitive impairment and co-occurrence of cognitive and neuropsychiatric impairment showed the highest risk of incident dementia, which may be attributed to both neurodegenerative and cerebrovascular pathologies.

Emotion regulation in people living with dementia and their spouses: the role of neuropsychiatric symptoms

OBJECTIVES

People with dementia (PwD) and their care partners (CP) may have difficulties in emotion regulation, and individual differences in emotion regulation may be related to PwD's neuropsychiatric symptoms. This study explores whether there is self-awareness of PwD's difficulties in emotion regulation and whether CP's emotion regulation relates to the PwD's neuropsychiatric symptoms, potentially revealing bias or interpersonal effects.

METHOD

We used data from the Wish Outcome Obstacle Plan Study with a sample of 45 PwD and their spousal CP (n = 90 individuals). Multivariate linear regression models were used to investigate the associations between the CP-reported neuropsychiatric symptoms in PwD and self-reports of emotion regulation in both dyad members, net of sociodemographic and health factors. Separate analyses were conducted for each neuropsychiatric subsyndrome and each domain of difficulties in emotion regulation.

RESULTS

Increasing severity of neuropsychiatric symptoms was associated with higher difficulties in emotion regulation in PwD (ß = 1.23, p < 0.05), but not with CP's difficulties in emotion regulation. When CP reported more severe neuropsychiatric symptoms in PwD, PwD reported that they had difficulties in accepting emotions, controlling impulses, goal-directed behaviors, and accessing emotion regulation strategies, but not in emotion awareness and clarification. Proxy-reports of hyperactivity and psychosis subsyndromes are significantly related to PwD's self-reported difficulties in emotion regulation.

CONCLUSION

PwD reported difficulties in emotion regulation at the early stage of dementia. Proxy-reported neuropsychiatric symptoms may capture PwD's emotion regulation capability and not be biased by CP's difficulties in emotion regulation.

The Difference in Cognitive Profiles Between Patients With Alzheimer Dementia With and Without Psychosis: A Rapid Review

BACKGROUND

Psychosis in Alzheimer disease (AD) is a major burden for patients and their family. Identifying the characteristics of delusions and hallucinations in the AD population is key to understanding the interconnection between the psychiatric and cognitive symptoms in neurocognitive disorders. The aim of this study is to compare the cognitive profiles of AD patients with and without psychosis.

METHODS

We conducted a rapid review to explore the relationship between psychotic symptoms and cognitive performances in patients with AD. We used MEDLINE, Embase, and PsychINFO literature databases between January 2015 and January 2023. This rapid review was guided by the Cochrane Rapid Reviews Methods Group.

RESULTS

We identified 2909 records from the initial searches. After reviewing the titles, abstracts, and full texts, we selected 8 cross-sectional and 5 cohort studies for the qualitative analysis. Among them, 6 studies were included in the final quantitative analysis. Most studies suggested a correlation between general cognitive decline and the risk of presenting psychotic symptoms. Three studies found an association between hallucinations and deficits in the visuocognitive domains (visuospatial, visuoperceptual, and visuoconstructive skills). Two studies found a relationship between psychotic symptoms and executive dysfunction. Two studies also found a correlation between psychotic symptoms and language. Our results are in line with previous data in the literature, especially regarding the outcome of psychosis on executive function and visuocognitive abilities.

CONCLUSIONS

There appears to be an association between cognitive deficits and psychotic symptoms in AD, but the direction of causality is still unclear, and further studies using longitudinal designs would give more insight into the pathophysiological process of psychosis in AD.

Prevalence of psychotic symptoms in mild cognitive impairment: A systematic review and meta-analysis

INTRODUCTION

Neuropsychiatric symptoms may impact prognosis in individuals with mild cognitive impairment (MCI); however, data on frequency of psychotic symptoms are sparse.

METHODS

We searched MEDLINE, EMBASE, PsychoINFO from inception to June 2023. We included studies reporting patients with MCI prevalence of (delusions and/or hallucinations. Random effects model were performed to estimate the prevalence, and subgroup and meta-regression analyses were performed to explore heterogeneity.

RESULTS

Of 3145 records identified, 36 studies were included, enrolling 20,426 patients. Overall prevalence of hallucinations was 1.78 % (95 % CI, 1.17 - 2.71) and delusions 3.84 % (95 % CI, 2.71 - 5.42), both with significant heterogeneity (/2 = 90 %). Prevalence of hallucinations and delusions were lower when measured by NPI scales and in population-based samples.

DISCUSSION

Delusions and hallucinations occur in MCI patients at low rates. Prevalence can be partially explained by the assessment method, sample source and study heterogeneity.

Neuropsychiatric symptom burden in early-onset and late-onset Alzheimer's disease as a function of age

INTRODUCTION

We examined the burden of neuropsychiatric symptoms (NPSs) in early-onset (EO) and late-onset (LO) Alzheimer's disease (AD) and adjusted for age effects via the inclusion of cognitively unimpaired (CU) individuals.

METHODS

Cross-sectional data from 2940 EOAD, 8665 LOAD, and 8775 age-stratified CU individuals (early-CU, n = 2433; late-CU, n = 6342) from the National Alzheimer's Coordinating Center database were included. Fisher's exact tests compared EOAD and LOAD on the presence and severity of NPSs. Multiple logistic regression models included an age*diagnosis interaction to examine age effects.

RESULTS

Presence (ps < 0.0001) and severity (ps < 0.05) of NPS were greater in EOAD than in LOAD. However, after adjusting for base rates in NPS in CU individuals (age effects), only elation and eating behaviors were more frequent in EOAD (ps < 0.05) and nighttime behaviors more frequent and severe in LOAD (ps < 0.05).

DISCUSSION

Few NPSs were specific to the EOAD versus LOAD. Previous findings of greater NPS burden in EOAD may partially reflect age effects.

HIGHLIGHTS

Adjusting for age effect, elation and eating problems are more frequent in EOAD. Adjusting for age effect, sleep disturbances are more frequent and severe in LOAD. Age effects underlie higher neuropsychiatric symptom presentation in EOAD than in LOAD.

Neuropsychiatric Symptoms Predict Faster Cognitive Decline in Dementia Collaborative Care Than Antipsychotic Use

Background

To compare short-term cognitive outcomes among groups with and without neuropsychiatric symptoms (NPSs) or antipsychotic prescription and to determine which disease status or treatment modality is associated with relatively faster cognitive decline.

Methods

We retrospectively analyzed a prospective cohort of patients diagnosed with dementia and mild cognitive impairment. All participants were evaluated using the Cognitive Abilities Screening Instrument (CASI) during their initial clinical assessments and at the annual follow-up. The dependent variable was annual delta CASI. Multivariate linear regression analysis was used to assess the degree of association between NPS, antipsychotic use, and cognitive decline after adjusting for confounding factors. Neuropsychiatric symptoms were examined individually to determine their predictive value for cognitive decline.

Results

A total of 407 (N = 407) patients were included in the study. NPSs, rather than antipsychotic use, led to faster cognitive decline. A higher baseline NPI total score predicted a significantly faster decline in CASI scores (1-year delta CASI = -0.22, 95% CI = -0.38~ -0.05, p = 0.010). Specific items (delusions, agitation, depression, anxiety, euphoria, and apathy) in the NPS significantly increased cognitive decline.

Conclusion

Certain neuropsychiatric symptoms, rather than antipsychotic use, lead to faster cognitive decline in a dementia collaborative care model. Checking for and providing appropriate interventions for NPS in people with dementia and their caregivers are highlighted.

Amyloid Pathology Modulates the Associations of Neuropsychiatric Symptoms with Cognitive Impairments and Neurodegeneration in Non-Demented Elderly

BACKGROUND

The associations between neuropsychiatric symptoms (NPSs) and Alzheimer's disease (AD) have been well-studied, yet gaps remain.

OBJECTIVE

We aimed to examine the associations of four subsyndromes (hyperactivity, psychosis, affective symptoms, and apathy) of NPSs with cognition, neurodegeneration, and AD pathologies.

METHODS

Totally 1,040 non-demented elderly (48.07% males) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were included. We assessed the relationships between NPSs and AD neuropathologies, cognition, neurodegeneration, and clinical correlates in cross-sectional and longitudinal via multiple linear regression, linear mixed effects, and Cox proportional hazard models. Causal mediation analyses were conducted to explore the mediation effects of AD pathologies on cognition and neurodegeneration.

RESULTS

We found that individuals with hyperactivity, psychosis, affective symptoms, or apathy displayed a poorer cognitive status, a lower CSF amyloid-β (Aβ) level and a higher risk of clinical conversion (p < 0.05). Hyperactivity and affective symptoms were associated with increasing cerebral Aβ deposition (p < 0.05). Except psychosis, the other three subsyndromes accompanied with faster atrophy of hippocampal volume (p < 0.05). Specific NPSs were predominantly associated with different cognitive domains decline through an 8-year follow-up (p < 0.05). Moreover, the relationships between NPSs and cognitive decline, neurodegeneration might be associated with Aβ, the mediation percentage varied from 6.05% to 17.51% (p < 0.05).

CONCLUSIONS

NPSs could be strongly associated with AD. The influences of NPSs on cognitive impairments, neurodegeneration might be partially associated with Aβ.

Differentiating Alzheimer's disease from mild cognitive impairment: a quick screening tool based on machine learning

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder characterised by cognitive decline, behavioural and psychological symptoms of dementia (BPSD) and impairment of activities of daily living (ADL). Early differentiation of AD from mild cognitive impairment (MCI) is necessary.

METHODS

A total of 458 patients newly diagnosed with AD and MCI were included. Eleven batteries were used to evaluate ADL, BPSD and cognitive function (ABC). Machine learning approaches including XGboost, classification and regression tree, Bayes, support vector machines and logical regression were used to build and verify the new tool.

RESULTS

The Alzheimer's Disease Assessment Scale (ADAS-cog) word recognition task showed the best importance in judging AD and MCI, followed by correct numbers of auditory verbal learning test delay recall and ADAS-cog orientation. We also provided a selected ABC-Scale that covered ADL, BPSD and cognitive function with an estimated completion time of 18 min. The sensitivity was improved in the four models.

CONCLUSION

The quick screen ABC-Scale covers three dimensions of ADL, BPSD and cognitive function with good efficiency in differentiating AD from MCI.

Dissecting the Relationship Between Neuropsychiatric and Neurodegenerative Disorders

Neurodegenerative diseases (NDDs) and neuropsychiatric disorders (NPDs) are two common causes of death in elderly people, which includes progressive neuronal cell death and behavioral changes. NDDs include Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and motor neuron disease, characterized by cognitive defects and memory impairment, whereas NPDs include depression, seizures, migraine headaches, eating disorders, addictions, palsies, major depressive disorders, anxiety, and schizophrenia, characterized by behavioral changes. Mounting evidence demonstrated that NDDs and NPDs share an overlapping mechanism, which includes post-translational modifications, the microbiota-gut-brain axis, and signaling events. Mounting evidence demonstrated that various drug molecules, namely, natural compounds, repurposed drugs, multitarget directed ligands, and RNAs, have been potentially implemented as therapeutic agents against NDDs and NPDs. Herein, we highlighted the overlapping mechanism, the role of anxiety/stress-releasing factors, cytosol-to-nucleus signaling, and the microbiota-gut-brain axis in the pathophysiology of NDDs and NPDs. We summarize the therapeutic application of natural compounds, repurposed drugs, and multitarget-directed ligands as therapeutic agents. Lastly, we briefly described the application of RNA interferences as therapeutic agents in the pathogenesis of NDDs and NPDs. Neurodegenerative diseases and neuropsychiatric diseases both share a common signaling molecule and molecular phenomenon, namely, pro-inflammatory cytokines, γCaMKII and MAPK/ERK, chemokine receptors, BBB permeability, and the gut-microbiota-brain axis. Studies have demonstrated that any alterations in the signaling mentioned above molecules and molecular phenomena lead to the pathophysiology of neurodegenerative diseases, namely, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, and neuropsychiatric disorders, such as bipolar disorder, schizophrenia, depression, anxiety, autism spectrum disorder, and post-traumatic stress disorder.

Polygoni Multiflori Radix Praeparata and Acori Tatarinowii Rhizoma ameliorate scopolamine-induced cognitive impairment by regulating the cholinergic and synaptic associated proteins

ETHNOPHARMACOLOGICAL RELEVANCE

The combination of Polygoni Multiflori Radix Praeparata (PMRP) and Acori Tatarinowii Rhizoma (ATR) is often used in traditional Chinese medicine to prevent and treat Alzheimer's disease (AD). However, it is not clear whether the effects and mechanisms of the decoction prepared by traditional decocting method (PA) is different from that prepared by modern decocting method (P + A).

AIM OF THE STUDY

The present study aimed to investigate the differences in the protective effects of PA and P + A on scopolamine induced cognitive impairment, and to explore its potential mechanism.

MATERIALS AND METHODS

To assess the protective effect of PA and P + A on cognitive dysfunction, the mice were orally administrated with PA (1.56, 6.24 g kg^-1•day^-1) and P + A (1.56, 6.24 g kg^-1•day^-1) for 26 days before co-treatment with scopolamine (4 mg kg^-1•day^-1, i.p.). The learning and memory abilities of mice were examined by Morris water maze test, and the expressions of proteins related to cholinergic system and synaptic function were detected by the methods of ELISA, real-time PCR and Western blotting. Then, molecular docking technique was used to verify the effect of active compounds in plasma after PA administration on Acetylcholinesterase (AChE) protein. Finally, the Ellman method was used to evaluate the effects of different concentrations of PA, P + A (1 μg/mL-100 mg/mL) and the compounds (1-100 μM) on AChE activity in vitro.

RESULTS

On one hand, in the scopolamine-induced cognitive impairment mouse model, both of PA and P + A could improve the cognitive impairment, while the effect of PA on cognitive amelioration was better than that of P + A. Moreover, PA regulated the cholinergic and synaptic functions by enhancing the concentration of acetylcholine (ACh), the mRNA levels of CHT1, Syn, GAP-43 and PSD-95, and the related proteins (CHT1, VACHT, Syn, GAP-43 and PSD-95), and significantly inhibiting the expression of AChE protein. Meanwhile, P + A only up-regulated the mRNA levels of GAP-43 and PSD-95, increased the expressions of CHT1, VACHT, Syn, GAP-43 and PSD-95 proteins, and inhibited the expression of AChE protein. On the other hand, the in vitro study showed that some compounds including emodin-8-o-β-d-Glucopyranoside, THSG and α-Asarone inhibited AChE protein activity with the IC₅₀ values 3.65 μM, 5.42 μM and 9.43 μM, respectively.

CONCLUSIONS

These findings demonstrate that both of PA and P + A can ameliorate the cognitive deficits by enhancing cholinergic and synaptic related proteins, while PA has the stronger improvement effect on the cholinergic function, which may be attributed to the compounds including THSG, emodin, emodin-8-O-β-D-glucopyranoside and α-asarone. The present study indicated that PA has more therapeutic potential in the treatment of neurodegenerative diseases such as AD. The results provide the experimental basis for the clinical use of PA.

Characterization of apathy-like behaviors in the 5xFAD mouse model of Alzheimer's disease

Most patients with Alzheimer's disease (AD) develop neuropsychiatric symptoms (NPS) alongside cognitive decline, and apathy is one of the most common symptoms. Few preclinical studies have investigated the biological substrates underlying NPS in AD. In this study, we used a cross-sectional design to characterize apathy-like behaviors and assess memory in 5xFAD and wildtype control mice at 6, 12, and 16 months of age. Nest building, burrowing, and marble burying were used to test representative behaviors of apathy, and a composite score of apathy-like behavior was generated from these assays. Soluble Aβ42 and plaques were quantified in the prefrontal cortex and hippocampus of the 5xFAD mice with the highest and lowest composite scores using ELISA and histology. Results suggest that 5xFAD mice develop significant apathy-like behaviors starting at 6 months of age that worsen with aging and are positively correlated with soluble Aβ42 and plaques in the prefrontal cortex and hippocampus. Our findings highlight the utility of studying NPS in mouse models of AD to uncover important relationships with underlying neuropathology.

The Relationship between Neuropsychiatric Symptoms and Cognitive Performance in Older Adults with Normal Cognition

Background and Objectives: To explore whether specific Neuropsychiatric Symptoms (NPS) are related to worse performance in particular cognitive domains. Materials and Methods: A cross-sectional analysis of the baseline evaluations of older (≥60 years), cognitively unimpaired (CU) participants from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set was performed. Data were derived from 43 Alzheimer's Disease Research Centers. Cognitively impaired individuals, participants with psychiatric disorders and/or under treatment with antipsychotic, anxiolytic, sedative, or hypnotic agents were excluded. NPS were assessed using the Neuropsychiatric Inventory Questionnaire. The association of NPS with participants' performance on episodic memory, semantic memory, language, attention, processing speed and executive function was analysed using an adjusted (considering important demographic and medical factors) multivariate general linear model. Results: A total of 7179 CU, older, predominantly female, Caucasian, and well-educated participants were included in the present analysis. Among them, 1856 individuals had one or more NPS. Our analysis revealed that moderate/severe anxiety was related to worse performance on semantic memory, attention and executive function, the presence of hallucinations was linked to worse processing speed and executive function scores, while the presence of elation/euphoria and aberrant motor behaviour were associated with poorer attention and language performance, respectively. In the context of a secondary, exploratory analysis, the presence of moderate/severe delusions was related to worse processing speed and executive function performance. Conclusions: The relationship between specific NPS and worse performance in particular cognitive domains could inform the formulation of individualized preventive strategies directed to the ''fortification'' of specific cognitive functions in CU individuals with NPS.

Establishing an individualized model of conversion from normal cognition to Alzheimer's disease after 4 years, based on cognitive, brain morphology and neuropsychiatric characteristics

OBJECTIVES

The impact of neuropsychiatric symptoms (NPS) on cognitive performance has been reported, and this impact was better defined in the aging population. Yet the potential of using the impact of NPS on brain and cognitive performance in a longitudinal setting, as prediction of conversion - have remained questionable. This study proposes to establish a predictive model of conversion to Alzheimer's disease (AD) and mild cognitive impairment (MCI) based on current cognitive performance, NPS and their associations with brain morphology.

METHODS

156 participants with MCI from the Alzheimer's Disease Neuroimaging Initiative database cognitively stable after a 4-year follow-up were compared to 119 MCI participants who converted to AD. Each participant underwent a neuropsychological assessment evaluating verbal memory, language, executive and visuospatial functions, a neuropsychiatric inventory evaluation and a 3 Tesla MRI. The statistical analyses consisted of 1) baseline comparison between the groups; 2) analysis of covariance model (controlling demographic parameters including functional abilities) to specify the variables that distinguish the two subgroups and; 3) used the significant ANCOVA variables to construct a binary logistic regression model that generates a probability equation to convert to a lower cognitive performance state.

RESULTS

Results showed that MCI who converted to AD in comparison to stable MCI, exhibited a higher NPS prevalence, a lower cognitive performance and a higher number of involved brain structures. Functional abilities, memory performance and the sizes of inferior temporal, hippocampal and amygdala sizes were significant predictors of MCI to AD conversion. We also report two models of conversion that can be implemented on an individual basis for calculating the percentage risk of conversion after 4 years.

CONCLUSION

These analytical methods might be a good way to anticipate cognitive and brain declines.