Hospital-treated mental and behavioral disorders and risk of Alzheimer's disease: A nationwide nested case-control study

Menopausal symptom burden as a predictor of mid- to late-life cognitive function and mild behavioral impairment symptoms: A CAN-PROTECT study

BACKGROUND

Recent evidence suggests the experience of menopausal symptoms (i.e., perimenopausal symptoms) may be associated with cognitive and behavioural changes. We investigated these two relationships in a sample of postmenopausal females.

DESIGN

Cross-sectional observational study.

SETTING

Participant data was collected from the Canadian Platform for Research Online to Investigate Health, Quality of Life, Cognition, Behaviour, Function, and Caregiving in Aging (CAN-PROTECT) study.

PARTICIPANTS

896 postmenopausal female participants.

METHODS

Menopausal symptom burden was operationalized by summing the total number of recalled perimenopausal symptoms experienced. Cognitive function was measured using the Everyday Cognition (ECog-II) Scale, with higher scores reflecting greater severity. Mild Behavioral Impairment (MBI) was measured using the Mild Behavioral Impairment Checklist (MBI-C), with higher scores reflecting greater severity. A negative-binomial regression model examined the relationship between menopausal symptom burden and cognitive function, while a zero-inflated negative binomial regression model examined the relationship between menopausal symptom burden and MBI symptoms. Models adjusted for age, years of education, age of menopausal onset, type of menopause, and hormone therapy (HT). Age of menopausal onset and use of HT in the two associations were investigated with moderation analyses.

RESULTS

Greater menopausal symptom burden was associated with higher ECog-II total scores (b [95% confidence interval (CI)] = 5.37 [2.85, 7.97]) and higher MBI-C total scores (b [95% CI] = 6.09 [2.50, 9.80]). Use of HT did not significantly associate with ECog-II total scores (b [95% CI] = -10.98 [-25.33, 6.35]), however, HT was significantly associated with lower MBI-C total scores (b [95% CI] = -26.90 [-43.35, -5.67]).

CONCLUSIONS

Menopausal symptom burden is associated with poorer cognitive function and more MBI symptoms in mid- to late life. HT may help mitigate symptoms of MBI. These findings suggest that the experience of menopause may indicate susceptibility to cognitive and behavioural changes, both markers of dementia.

Predicting Alzheimer's disease from cognitive footprints in mid and late life: How much can register data and machine learning help?

BACKGROUND

Real-world data with decades-long medical records are increasingly available alongside the growing adoption of machine learning in healthcare research. We evaluated the performance of machine learning models in predicting the risk of Alzheimer's disease (AD) using data from the Finnish national registers.

METHODS

We conducted a case-control study using data from the Finnish MEDALZ (Medication use and Alzheimer's disease) study. Altogether 56,741 individuals with incident AD diagnosis (age ≥ 65 years at diagnosis and born after 1922) and their 1:1 age-, sex-, and region of residence-matched controls were included. The association of risk factors, evaluated at different age periods (45-54, 55-64, 65+), and AD were assessed with logistic regression. Predictive accuracies of logistic regressions were compared with seven machine learning models (L1-regularized logistic regression, Naive bayes, Decision tree, Random Forest, Multilayer perceptron, XGBoost, and LightGBM).

FINDINGS

63.5 % of cases and controls were females and the mean age was 79.1 (SD = 5.1). The strongest associations with AD were observed for head injuries at age 55-64 (OR, 95 % CI 1.33, 1.19-1.48) and 65+ (1.31, 1.23-1.40), followed by antidepressant use (1.30, 1.22-1.38) at 55-64 and antipsychotic use (1.27, 1.19-1.35) at 65+. The predictive accuracies of all models were low, with the best performance (AUC 0.603) observed in Random Forest for predicting AD onset at age 65-69.

INTERPRETATION

Although significant associations were identified between many risk factors and AD, the low predictive accuracies suggest that specialised healthcare diagnosis data is not sufficient for predicting AD and linkage with other data sources is needed.

The risk of Alzheimer's disease and cognitive impairment characteristics in eight mental disorders: A UK Biobank observational study and Mendelian randomization analysis

INTRODUCTION

The cognitive impairment patterns and the association with Alzheimer's disease (AD) in mental disorders remain poorly understood.

METHODS

We analyzed data from 486,297 UK Biobank participants, categorizing them by mental disorder history to identify the risk of AD and the cognitive impairment characteristics. Causation was further assessed using Mendelian randomization (MR).

RESULTS

AD risk was higher in individuals with bipolar disorder (BD; hazard ratio [HR] = 2.37, P < 0.01) and major depressive disorder (MDD; HR = 1.63, P < 0.001). MR confirmed a causal link between BD and AD (ORIVW = 1.098), as well as obsessive-compulsive disorder (OCD) and AD (ORIVW = 1.050). Cognitive impairments varied, with BD and schizophrenia showing widespread deficits, and OCD affecting complex task performance.

DISCUSSION

Observational study and MR provide consistent evidence that mental disorders are independent risk factors for AD. Mental disorders exhibit distinct cognitive impairment prior to dementia, indicating the potential different mechanisms in AD pathogenesis. Early detection of these impairments in mental disorders is crucial for AD prevention.

HIGHLIGHTS

This is the most comprehensive study that investigates the risk and causal relationships between a history of mental disorders and the development of Alzheimer's disease (AD), alongside exploring the cognitive impairment characteristics associated with different mental disorders. Individuals with bipolar disorder (BD) exhibited the highest risk of developing AD (hazard ratio [HR] = 2.37, P < 0.01), followed by those with major depressive disorder (MDD; HR = 1.63, P < 0.001). Individuals with schizophrenia (SCZ) showed a borderline higher risk of AD (HR = 2.36, P = 0.056). Two-sample Mendelian randomization (MR) confirmed a causal association between BD and AD (ORIVW = 1.098, P < 0.05), as well as AD family history (proxy-AD, ORIVW = 1.098, P < 0.001), and kept significant after false discovery rate correction. MR also identified a nominal significant causal relationship between the obsessive-compulsive disorder (OCD) spectrum and AD (ORIVW = 1.050, P < 0.05). Individuals with SCZ, BD, and MDD exhibited impairments in multiple cognitive domains with distinct patterns, whereas those with OCD showed only slight declines in complex tasks.

Mild behavioral impairment in early Alzheimer's disease and its association with APOE and BDNF risk genetic polymorphisms

BACKGROUND

Mild behavioral impairment (MBI) has been commonly reported in early Alzheimer's disease (AD) but rarely using biomarker-defined samples. It is also unclear whether genetic polymorphisms influence MBI in such individuals. We thus aimed to examine the association between the cognitive status of participants (amnestic mild cognitive impairment (aMCI-AD) vs cognitively normal (CN) older adults) and MBI severity. Within aMCI-AD, we further examined the association between APOE and BDNF risk genetic polymorphisms and MBI severity.

METHODS

We included 62 aMCI-AD participants and 50 CN older adults from the Czech Brain Aging Study. The participants underwent neurological, comprehensive neuropsychological examination, APOE and BDNF genotyping, and magnetic resonance imaging. MBI was diagnosed with the Mild Behavioral Impairment Checklist (MBI-C), and the diagnosis was based on the MBI-C total score ≥ 7. Additionally, self-report instruments for anxiety (the Beck Anxiety Inventory) and depressive symptoms (the Geriatric Depression Scale-15) were administered. The participants were stratified based on the presence of at least one risk allele in genes for APOE (i.e., e4 carriers and non-carriers) and BDNF (i.e., Met carriers and non-carriers). We used linear regressions to examine the associations.

RESULTS

MBI was present in 48.4% of the aMCI-AD individuals. Compared to the CN, aMCI-AD was associated with more affective, apathy, and impulse dyscontrol but not social inappropriateness or psychotic symptoms. Furthermore, aMCI-AD was related to more depressive but not anxiety symptoms on self-report measures. Within the aMCI-AD, there were no associations between APOE e4 and BDNF Met and MBI-C severity. However, a positive association between Met carriership and self-reported anxiety appeared.

CONCLUSIONS

MBI is frequent in aMCI-AD and related to more severe affective, apathy, and impulse dyscontrol symptoms. APOE and BDNF polymorphisms were not associated with MBI severity separately; however, their combined effect warrants further investigation.

Identifying Comorbidity Patterns in People with and without Alzheimer's Disease Using Latent Dirichlet Allocation

Background

Multimorbidity is common in older adults and complicates diagnosing and care for this population.

Objective

We investigated co-occurrence patterns (clustering) of medical conditions in persons with Alzheimer's disease (AD) and their matched controls.

Methods

The register-based Medication use and Alzheimer's disease study (MEDALZ) includes 70,718 community-dwelling persons with incident AD diagnosed during 2005-2011 in Finland and a matched comparison cohort. Latent Dirichlet Allocation was used to cluster the comorbidities (ICD-10 diagnosis codes). Modeling was performed separately for AD and control cohorts. We experimented with different numbers of clusters (also known as topics in the field of Natural Language Processing) ranging from five to 20.

Results

In both cohorts, 17 of the 20 most frequent diagnoses were the same. Based on a qualitative assessment by medical experts, the cluster patterns were not affected by the number of clusters, but the best interpretability was observed in the 10-cluster model. Quantitative assessment of the optimal number of clusters by log-likelihood estimate did not imply a specific optimal number of clusters. Multidimensional scaling visualized the variability in cluster size and (dis)similarity between the clusters with more overlapping of clusters and variation in group size seen in the AD cohort.

Conclusions

Early signs and symptoms of AD were more commonly clustered together in the AD cohort than in the comparison cohort. This study experimented with using natural language processing techniques for clustering patterns from an epidemiological study. From the computed clusters, it was possible to qualitatively identify multimorbidity that differentiates AD cases and controls.

[Comorbidity of depression and dementia: epidemiological, biological and therapeutic aspects]

The literature review is devoted to the problem of the relationship between dementia and depression, the role of depression as a risk factor for dementia and the place of depression in the structure of neurocognitive disorders in dementia. Epidemiological data are presented and the mechanisms of interrelation of disorders are considered. The search for sources included only qualitative research, meta-analyses, full-text articles and was conducted in the PubMed, Google system using the keywords «dementia, depression». The presented epidemiological and biological data indicate that depression increases the risk of dementia, confirming the hypothesis of a causal factor. The main directions of research on the relationship between depression and dementia in the context of Alzheimer's disease prevention are given.

TBX21, the Master regulator of the type 1 immune response, overexpresses in the leukocytes of peripheral blood in patients with late-onset Alzheimer's disease

BACKGROUND

The involvement of the peripheral immune system in the etiology of neurodegenerative diseases has recently been emphasized. Genome-wide association studies (GWAS) have recently identified several candidate immune genes linked to development of both Alzheimer's disease (AD) and depression. TBX21 (T-bet) which drives the Th1 immune response, is linked to the major depressive disorder (MDD) phenotype. This study investigated the association between the TBX21 immune gene and the possibility of late-onset Alzheimer's disease (LOAD) incidence in 194 LOAD and 200 control subjects using the real-time qPCR and the Tetra-ARMS-PCR methods. We also used an in silico approach to analyze the potential effects imparted by TBX21 rs17244587 and rs41515744 polymorphisms in LOAD pathogenesis.

RESULTS

We found that the TBX21 "immune gene" had significantly elevated mRNA expression levels in the leukocytes of peripheral blood in patients with LOAD (P < 0.0001). We also found an upward trend in TBX21 expression with increasing age in LOAD patients compared to the control group (P < 0.05; CI = 95%). We noticed that the TT genotype of rs41515744 plays a protective role in LOAD incidence, as it attenuates the expression of TBX21 in the control group. We observed that the dominant model of rs41515744 represented a substantial association with LOAD (P = 0.019).

CONCLUSIONS

Our results show for the first time the likely impact of the TBX21 (T-bet) immune gene in LOAD development and that the elevated TBX21 mRNAs in the WBCs of LOAD patients may represent a new easy diagnostic test for Alzheimer's disease.

Diagnostic groups of hospital stays and outpatient visits during 10 years before Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a major determinant of healthcare costs and increase in the healthcare service use occur already before the AD diagnosis. However, little is known how the different diagnosis categories contribute to this increase in healthcare use. We investigated how the hospitalizations and specialized healthcare outpatient visits from different diagnosis categories, based on the International Classification of Diseases (ICD-10) chapters, contribute to increased specialized healthcare service use during ten-year period preceding AD diagnosis.

METHODS

A register-based nationwide cohort of 42,934 community-dwelling persons who received clinically verified AD diagnosis in between 2008 and 2011 in Finland and 1:1 age, sex and hospital district- matched comparison cohort were included. Hospitalizations and specialized healthcare visits were categorized by the main diagnosis, according to the ICD-10 chapters. AD and dementia were separated to their own category. The number of persons with visits and stays was calculated for every 6 months, irrespective of the frequency of visits/stays individual had during that time window. Furthermore, the relative distribution of the diagnosis categories was computed.

RESULTS

AD cohort was more likely to have visits and stays during the 10-year period (OR 1.19, 95% CI 1.17-1.21). The number of persons with visits and stays peaked in AD cohort from 1.5 years before the diagnosis when the differences in relative distribution of different diagnosis categories also became evident. The largest differences were observed for visits/stays with cognitive disorders, symptoms of unspecified diseases and psychiatric disorders diagnoses, and those with missing diagnosis codes in the last time window before AD diagnosis.

CONCLUSIONS AND IMPLICATIONS

Increased healthcare service use before AD diagnosis does not seem to arise from differences in specific diagnosis categories of ICD-10 such as diseases of the circulatory system, but from the higher frequency of visits and stays among persons with AD across diagnosis categories. Based on the relative distribution of diagnosis categories, the steep increase in healthcare service use just before and during the diagnostic process is likely due to prodromal symptoms and visits related to cognition.

Distinguishing apathy from depression: A review differentiating the behavioral, neuroanatomic, and treatment-related aspects of apathy from depression in neurocognitive disorders

OBJECTIVES

This narrative review describes the clinical features of apathy and depression in individuals with neurocognitive disorders (NCDs), with the goal of differentiating the two syndromes on the basis of clinical presentation, diagnostic criteria, neuropathological features, and contrasting responses to treatments.

METHODS

Literature was identified using PubMed, with search terms to capture medical conditions of interest; additional references were also included based on our collective experience and knowledge of the literature.

RESULTS

Evidence from current literature supports the distinction between the two disorders; apathy and depression occur with varying prevalence in individuals with NCDs, pose different risks of progression to dementia, and have distinct, if overlapping, neurobiological underpinnings. Although apathy is a distinct neuropsychiatric syndrome, distinguishing apathy from depression can be challenging, as both conditions may occur concurrently and share several overlapping features. Apathy is associated with unfavorable outcomes, especially those with neurodegenerative etiologies (e.g., Alzheimer's disease) and is associated with an increased burden for both patients and caregivers. Diagnosing apathy is important not only to serve as the basis for appropriate treatment, but also for the development of novel targeted interventions for this condition. Although there are currently no approved pharmacologic treatments for apathy, the research described in this review supports apathy as a distinct neuropsychiatric condition that warrants specific treatments aimed at alleviating patient disability.

CONCLUSIONS

Despite differences between these disorders, both apathy and depression pose significant challenges to patients, their families, and caregivers; better diagnostics are needed to develop more tailored treatment and support.

Non-affective psychotic disorders and risk of dementia: a systematic review and meta-analysis

Non-affective psychotic disorders have been associated with an increased risk of developing dementia. However, research in this area remains limited, highlighting the need for an up-to-date systematic review and meta-analysis of the evidence. We aimed to systematically review and quantify the risk of dementia associated with psychotic disorders. We searched four electronic databases for longitudinal studies investigating non-affective psychotic disorders and subsequent dementia. We used random-effects meta-analyses to pool estimates across studies and assessed risk of bias for each study. Non-affective psychotic disorders were associated with increased risk of all-cause dementia; pooled risk ratio (RR) = 2.52, 95% confidence interval (CI) (1.67-3.80), I2 = 99.7%, n = 12,997,101; 11 studies, with high heterogeneity between studies. Subgroup analyses indicated stronger associations in studies with shorter follow-up periods, conducted in non-European countries, published after 2020, and where ≥60% of the sample were female. The risk was higher in people aged <60 years at baseline, in typical and late-onset psychotic disorders versus very late-onset psychosis, in broader psychotic disorders vs schizophrenia, and in prospective vs retrospective studies. Associations remained after excluding low quality studies (pooled RR = 2.50, 95% CI (1.71-3.68), I2 = 99.0%). Our review finds a substantial association between psychotic disorders and subsequent dementia. Our findings indicate that psychotic disorders are a potentially modifiable risk factor for dementia and suggest that individuals with psychotic disorders need to be closely monitored for cognitive decline in later life. Further research is needed to investigate the mechanisms underlying the association between psychotic disorders and dementia.

Use of α1-Adrenoceptor Antagonists Tamsulosin and Alfuzosin and The Risk of Alzheimer's Disease

Purpose

Tamsulosin has been associated with dementia, but the results have been inconsistent. Concerns have been raised about using exposure assessment time too close to the outcome. We investigated the association between use of α1‐adrenoceptor antagonists indicated for benign prostate hyperplasia and risk of Alzheimer's disease (AD) using different exposure windows.

Methods

The study (24 602 cases and 98 397 matched controls) included men from the Finnish nationwide nested case–control study on Medication and Alzheimer's disease (MEDALZ). Cases received clinically verified AD diagnosis during 2005–2011 and were community‐dwelling at the time of diagnosis. Use of tamsulosin and alfuzosin in 1995–2011 was identified from the Prescription Register and categorized based on whether it had occurred within 3 years before AD diagnosis (lag time) or before that. Dose–response analysis using defined daily doses of drug (DDDs) was conducted. Associations were investigated with conditional logistic regression, adjusted for confounders and mediators.

Results

The use of α1‐adrenoceptor antagonists before lag time associated with an increased risk of AD (OR 1.24 [1.20–1.27]). After adjustment for comorbidities and concomitant drug use throughout the assessment time (confounders) and healthcare contacts within the lag period (mediators), the association weakened (aOR 1.10 [1.06–1.14]). We found no evidence of dose–response‐relationship when comparing the users of higher than median DDDs to the users of lower than median DDDs.

Conclusion

Our findings, especially the lack of dose–response‐relationship and attenuation after mediator adjustment, do not provide strong support for the previous hypothesis on α1‐adrenoceptor antagonists as a risk factor for dementia.

Prevalence and characteristics of psychiatric morbidity treated in specialized health care in a nationwide cohort of people with newly diagnosed Alzheimer's disease

OBJECTIVE

Psychiatric disorders have been implied as both risk factors and prodromal symptoms of Alzheimer's disease (AD). A better understanding of the history of psychiatric morbidity in people with AD may aid with understanding this relationship and highlight challenges in diagnosing AD in people with concomitant psychiatric disorders.

METHODS

Medication use and Alzheimer's disease (MEDALZ) study is a nationwide register-based cohort of people (n = 70,718) who received a clinically verified AD diagnosis in Finland in 2005-2011 and were community-dwelling at the time of diagnosis. The study population was divided into four groups based on psychiatric morbidity treated in specialized health care. We characterized the groups using data of psychiatric and somatic illnesses, psychotropic drug use, and socioeconomic factors and investigated factors associated with prodromal AD.

RESULTS

Altogether, 4.3% of cohort members had a psychiatric diagnosis at least five years before AD diagnosis, 3.1% had a psychiatric diagnosis only up to five years before AD diagnosis, and 1.1% had a psychiatric diagnosis both less and more than 5 years before AD. Belonging to the Prodromal group (psychiatric diagnosis within 5 years before AD diagnosis) was most strongly associated with substance abuse (RR 65.06, 95%CI 55.54-76.22). Other associated factors with the Prodromal group were female gender, use of psychotropics, stroke, and asthma/COPD.

CONCLUSION

Substance abuse and psychotropic drug use are common five years before AD diagnosis. These can be potential markers of possible prodromal symptoms of AD and should be acknowledged in clinical work.

Psychiatric disorders and risk of subsequent dementia: Systematic review and meta-analysis of longitudinal studies

OBJECTIVES

Although psychiatric disorders have been found to be associated with increased risk of dementia, previous findings are mixed, and the nature of these relationships remains poorly understood. We examined longitudinal associations between depression, anxiety, post-traumatic stress disorders (PTSD), bipolar disorder (BPD), psychotic disorders and subsequent dementia.

METHODS

We searched three databases for longitudinal, population-based studies investigating associations between psychiatric disorders and dementia (PROSPERO registration: CRD42020209638). We conducted narrative synthesis, and random-effects meta-analyses to obtain pooled estimates. We used meta-regression and stratified analyses to examine variation by sex, age-at-onset and follow-up time.

RESULTS

Fifty-seven citations met eligibility criteria. Most studies focussed on depression (n = 33), which was associated with subsequent all-cause dementia (pooled relative risk [RR]: 1.96, 95% confidence interval [CI]: 1.59-2.43; I2 = 96.5%), Alzheimer's Disease (pooled RR: 1.9, 95% CI: 1.52-2.38; I2 = 85.5%), and Vascular Dementia (pooled RR: 2.71, 95% CI: 2.48-2.97; I2 = 0). Associations were stronger in studies with shorter follow-up periods and for severe and late-onset depression. Findings regarding anxiety were mixed, and we did not find evidence of an overall association (pooled RR: 1.18, 95% CI: 0.96-1.45; I2 = 52.2%, n = 5). Despite sparse evidence, psychotic disorders (pooled RR: 2.19, 95% CI: 1.44-3.31; I2 = 99%), PTSD and BPD were associated with subsequent dementia.

CONCLUSIONS

People with psychiatric disorders represent high-risk groups for dementia, highlighting the importance of ongoing symptom monitoring in these groups. Findings regarding temporality and age-at-onset indicate that depression symptoms could reflect prodromal dementia for some individuals. Further longitudinal research is required to determine whether psychiatric disorders represent causal risk factors or early markers of dementia neuropathology.

Late-Life Depression, Cognitive Impairment, and Relationship with Alzheimer's Disease

This narrative review aimed to explore the existing knowledge in order to examine the multiple forms of late-life depression (LLD) within a non-neurodegenerative or a neurodegenerative context, in particular Alzheimer's disease (AD). This review will first provide information about different pathogenic hypotheses proposed to describe LLD when it is not linked to a neurodegenerative context. Within the presentation of these syndromes, the literature reports thymic and cognitive specific features and highlights a common preponderance of cognitive impairment, and particularly executive. This review will also report data from research works that have addressed the role of depressive symptoms (DSs) in incidence of AD and mild cognitive impairment (MCI) conversion to AD. These findings support the claim that the relationship between DS (or LLD) and the cognitive decline encountered in AD can be of 2 types: (1) risk factor or (2) prodrome. They also support the hypothesis that the effect of DS on the incidence of AD can be identified between specific characteristics of these symptoms such as a very first apparition late in life, an increasing severity of DS, and a poor response to medical treatment. Finally, longitudinal and cross-sectional research will be presented, aiming to identify the predictive value of DS (or LLD) on AD incidence and/or conversion of MCI (and specifically amnestic MCI). This final section shows that specific features of LLD, such as being of early- or late-onset, can be considered as indices of AD incidence.

Antipsychotic Use and Risk of Stroke Among Community-Dwelling People With Alzheimer's Disease

OBJECTIVES

Antipsychotic use for neuropsychiatric symptoms in Alzheimer's disease (AD) is common despite the increased risk of cardiovascular events and mortality. There is limited and inconsistent evidence on the possible risk of stroke. We assessed whether antipsychotic initiation increases the risk of stroke in people with a verified diagnosis of AD and whether there is a difference in stroke risk between the 2 most commonly used antipsychotics, risperidone and quetiapine.

DESIGN

Register-based exposure-matched cohort study.

SETTING AND PARTICIPANTS

The Medication Use and Alzheimer's Disease (MEDALZ) cohort included 70,718 community-dwelling people with AD in Finland during 2005-2011. People with previous strokes were excluded.

METHODS

For each incident antipsychotic user (n = 20,467), 1 nonuser was matched according to sex, age, and time since AD diagnosis. Analyses were conducted with inverse probability of treatment-weighted (IPTW) Cox proportional hazards models.

RESULTS

Compared with nonuse, antipsychotic use was associated with an increased risk of stroke within 60 days of antipsychotic initiation [IPTW hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.32-2.28]. However, there was no significant overall association between antipsychotic use and the risk of stroke (IPTW HR 1.09, 95% CI 0.98-1.22). There was no difference in stroke risk between risperidone and quetiapine (IPTW HR 1.12, 95% CI 0.91-1.37).

CONCLUSIONS AND IMPLICATIONS

Stroke risk is increased shortly after antipsychotic initiation in people with AD, suggesting that even short-term use of antipsychotics should be avoided if possible. If antipsychotics are prescribed, effectiveness and safety should be assessed soon after initiation and treatment limited to the shortest possible duration.

Mild Behavioral Impairment: A New At-Risk State for Alzheimer's Disease?

Improving our response to Alzheimer's disease (AD), including prevention and early intervention, is critical for maximizing healthy aging outcomes. Identifying older adults at highest risk for AD would provide an opportunity to offer support, plan for the future, and implement strategies to enhance cognitive and functional outcomes. The emergence of neuropsychiatric symptoms may be one indicator of early AD-related cognitive decline, but distinguishing symptoms from those due to other causes can be challenging. Mild behavioral impairment (MBI) describes an at-risk state for cognitive decline characterized by the late-life onset of neuropsychiatric symptoms. In this article, we discuss the current conceptualization of MBI, the potential for its characteristic neuropsychiatric symptoms to indicate risk for future cognitive decline, and present potential clinical implications. [Journal of Gerontological Nursing, 47(3), 29-36.].

Association of recent hospitalisation with antidepressant initiation among community dwellers with Alzheimer's disease

OBJECTIVES

Antidepressant are commonly prescribed to persons with cognitive disorders to treat depressive and other neuropsychiatric symptoms despite the inconclusive evidence on their effectiveness on this indication. We studied whether recent hospitalisation was associated with antidepressant initiation in people with Alzheimer's disease (AD).

METHODS

The register-based Finnish nationwide Medication use and Alzheimer's disease cohort includes community-dwelling persons diagnosed with AD during 2005-2011 in Finland (n = 70,718). This study was restricted to people who initiated antidepressant use after AD diagnosis and had no active cancer treatment and schizophrenia or bipolar disorder diagnoses. We performed a nested case-control study with antidepressant initiators as cases. A matched noninitiator (sex, age and AD duration), was identified for each initiator (15,360 matched pairs). Recent hospitalisation was defined as hospital discharge within the past 14 days of initiation.

RESULTS

Antidepressant initiators were four times more likely (adjusted odds ratio: 4.41, 95% confidence interval: 4.06-4.80) to have been hospitalised within the past 2 weeks before initiation (21.2%, n = 3250) than matched noninitiators (5.4%, n = 831) and the duration of hospital stay was significantly longer among initiators. Dementia was the most common main discharge diagnosis among both initiators (43.8%, n = 1423) and noninitiators (24.8%, n = 206).

CONCLUSION

Recent hospitalisation was strongly associated with antidepressant initiation in persons with AD. Further studies are needed to investigate whether this is due to neuropsychiatric symptoms leading to hospital admission, inpatient care triggering or worsening neuropsychiatric symptoms or other indications. Nonpharmacological treatments for neuropsychiatric symptoms should be prioritised and the threshold for prescribing antidepressants should be high.

Mild Behavioral Impairment Is Associated With Atrophy of Entorhinal Cortex and Hippocampus in a Memory Clinic Cohort

Objectives

Mild behavioral impairment (MBI) is a syndrome describing late-onset persistent neuropsychiatric symptoms (NPS) in non-demented older adults. Few studies to date have investigated the associations of MBI with structural brain changes. Our aim was to explore structural correlates of NPS in a non-demented memory clinic sample using the Mild Behavioral Impairment Checklist (MBI-C) that has been developed to measure MBI.

Methods

One hundred sixteen non-demented older adults from the Czech Brain Aging Study with subjective cognitive concerns were classified as subjective cognitive decline (n = 37) or mild cognitive impairment (n = 79). Participants underwent neurological and neuropsychological examinations and brain magnetic resonance imaging (MRI) (1.5 T). The Czech version of the MBI-C was administered to participants’ informants. Five a priori selected brain regions were measured, namely, thicknesses of the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and entorhinal cortex (ERC) and volume of the hippocampus (HV), and correlated with MBI-C total and domain scores.

Results

Entorhinal cortex was associated with MBI-C total score (r_S = −0.368, p < 0.001) and with impulse dyscontrol score (r_S = −0.284, p = 0.002). HV was associated with decreased motivation (r_S = −0.248, p = 0.008) and impulse dyscontrol score (r_S = −0.240, p = 0.011).

Conclusion

Neuropsychiatric symptoms, particularly in the MBI impulse dyscontrol and motivation domains, are associated with medial temporal lobe atrophy in a clinical cohort of non-demented older adults. This study supports earlier involvement of temporal rather than frontal regions in NPS manifestation. Since these regions are typically affected early in the course of Alzheimer’s disease (AD), the MBI-C may potentially help further identify individuals at-risk of developing AD dementia.

Depression as a Risk Factor for Alzheimer's Disease: A Systematic Review of Longitudinal Meta-Analyses

Alzheimer’s disease (AD) is the most frequent cause of dementia, linked to morbidity and mortality among elderly patients. Recently, several clinical studies suggested that depression is a potential risk factor for cognitive decline and AD. A review of meta-analyses was performed, calculating pooled odds ratios to estimate the risk of AD in people with a prior diagnosis (or clinically significant symptoms) of depression. A total of six meta-analyses which represented 28 individual studies were analyzed. A significant association between depression and AD was found (OR = 1.54, 95% CI [1.02–2.31]; p = 0.038). The results showed that heterogeneity across studies was substantial. We found a significant positive effect size for clinical measures of depression, but not for symptomatic rating scales, in the association of depression with risk of AD. The type of rating scale used to assess depression and the cut-off criteria selected also moderated the relationship between depression and AD risk. We found that studies that used clinically significant criteria for diagnosis of depression had more consistent and significant results than studies that used symptomatic scales.

Mild Behavioral Impairment and Subjective Cognitive Decline Predict Cognitive and Functional Decline

BACKGROUND

Mild behavioral impairment (MBI) and subjective cognitive decline (SCD) are dementia risk states, and potentially represent neurobehavioral and neurocognitive manifestations, respectively, of early stage neurodegeneration. Both MBI and SCD predict incident cognitive decline and dementia, are associated with known dementia biomarkers, and are both represented in the NIA-AA research framework for AD in Stage 2 (preclinical disease).

OBJECTIVE

To assess the associations of MBI and SCD, alone and in combination, with incident cognitive and functional decline in a population of older adults. We tested the hypothesis that MBI and SCD confer additive risk for decline.

METHODS

Cognitively normal participants were followed up annually at Alzheimer's Disease Centers. Logistic regression assessed the relationship between baseline classification (MBI-SCD-, MBI-SCD+, MBI+SCD-, or MBI+SCD+) and 3-year outcome.

RESULTS

Of 2,769 participants (mean age=76), 1,536 were MBI-SCD-, 254 MBI-SCD+, 743 MBI+SCD-, and 236 MBI+SCD+. At 3 years, 349 (12.6%) declined to CDR >0, including 23.1% of the MBI+group, 23.5% of the SCD+group, and 30.9% of the intersection group of both MBI+and SCD+participants. Compared to SCD-MBI-, we observed an ordinal progression in risk (ORs [95% CI]): 3.61 [2.42-5.38] for MBI-SCD+ (16.5% progression), 4.76 [3.57-6.34] for MBI+SCD- (20.7%), and 8.15 [5.71-11.64] for MBI+SCD+(30.9%).

CONCLUSION

MBI and SCD together were associated with the greatest risk of decline. These complementary dementia risk syndromes can be used as simple and scalable methods to identify high-risk patients for workup or for clinical trial enrichment.

β-amyloid pathology is not associated with depression in a large community sample autopsy study

BACKGROUND

Depression has been associated with dementia. This study aimed to verify if β-amyloid Alzheimer's disease-type burden was associated with lifetime major depressive disorder (MDD) and with current depressive symptoms in a large population-based autopsy study.

METHODS

We included 1013 deceased subjects submitted to autopsy (mean age=74.3±11.6 years, 49% men) in a community sample. β-amyloid burden was measured in all cases based on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria for presence and density of neuritic plaques. Lifetime MDD was defined when at least one previous episode according to the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders - DSM (SCID). Depressive symptoms and cognitive impairment were determined using the depression item of the Neuropsychiatric Inventory (D-NPI>0) and the Clinical Dementia Rating scale (CDR>0.5) respectively.

RESULTS

Lifetime MDD, late life depression (LLD) and current depressive symptoms were associated with cognitive impairment (p<0.001). Additionally, neuritic plaques were associated with cognitive impairment (p<0.001). Moderate or frequent neurite plaque density was not associated with MDD, LLD or current depressive symptoms in multiple logistic models adjusted for age, gender, and cognitive impairment.

LIMITATIONS

In this cross-sectional study, all neuropsychiatric and cognitive assessment were based on informant-report of deceased participants.

CONCLUSIONS

Different clinical depictions of depression were associated with dementia in this large community sample of elderly individuals with multiethnic backgrounds. Notwithstanding, they were unrelated to β-amyloid pathology in the brain areas studied. The link between depression and dementia might be complex and determined by multiple factors.

Evaluating the Real-World Representativeness of Participants with Mild Cognitive Impairment in Canadian Research Protocols: a Comparison of the Characteristics of a Memory Clinic Patients and Research Samples

Background

Studies of mild cognitive impairment (MCI) employ rigorous eligibility criteria, resulting in sampling that may not be representative of the broader clinical population.

Objective

To compare the characteristics of MCI patients in a Calgary memory clinic to those of MCI participants in published Canadian studies.

Methods

Clinic participants included 555 MCI patients from the PROspective Registry of Persons with Memory SyMPToms (PROMPT) registry in Calgary. Research participants included 4,981 individuals with MCI pooled from a systematic literature review of 112 original, English-language peer-reviewed Canadian studies. Both samples were compared on baseline sociodemographic variables, medical and psychiatric comorbidities, and cognitive performance for MCI due to Alzheimer’s disease and Parkinson’s disease.

Results

Overall, clinic patients tended to be younger, more often male, and more educated than research participants. Psychiatric disorders, traumatic brain injury, and sensory impairment were commonplace in PROMPT (up to 83% affected) but > 80% studies in the systematic review excluded these conditions. PROMPT patients also performed worse on global cognition measures than did research participants.

Conclusion

Stringent eligibility criteria in Canadian research studies excluded a considerable subset of MCI patients with comorbid medical or psychiatric conditions. This exclusion may contribute to differences in cognitive performance and outcomes compared to real-world clinical samples.

The temporal association between incident late-life depression and incident dementia

OBJECTIVE

There is an established association between depression and subsequent dementia. The present study examined temporal associations between incident late-life depression and subsequent dementia, also considering age and sex.

METHODS

We used longitudinal health claims data from the largest German health insurance provider ('Allgemeine Ortskrankenkasse') considering up to 9 follow-up years in piecewise exponential models. ICD-10 codes were used to define incident depression and dementia in individuals ≥65 years (n = 97 110).

RESULTS

Incident depression was associated with a higher risk of subsequent dementia (incidence rate ratios (IRR) adjusted for age and sex: IRR = 1.58, 95% CI = 1.51-1.64). The strongest association was found for the shortest interval of 1 quarter (IRR = 2.04, 95% CI = 1.88-2.21), with significant associations up to an interval of roughly 3 years. The association was more pronounced and lasted for more quarters in the younger portion of this study group (ages from 65-74: IRR = 2.00, 95% CI = 1.83-2.18; 75-84: IRR = 1.64, 95% CI = 1.55-1.73; ≥85: IRR = 1.19, 95% CI = 1.08-1.31). It was stronger among men than women (men: IRR = 1.98, 95% CI = 1.84-2.14; women: IRR = 1.44, 95% CI = 1.37-1.51) with no sex-specific temporal association.

CONCLUSION

This large claims data study confirmed that incident late-life depression is associated with a higher risk of dementia within the 3 years following diagnosis. Hence, incident late-life depression should prompt further cognitive examinations and referrals to specialists. This might apply especially to younger seniors and men.

CCCDTD5 recommendations on early non cognitive markers of dementia: A Canadian consensus

Introduction

Cognitive impairment is the hallmark of Alzheimer's disease (AD) and related dementias. However, motor decline has been recently described as a prodromal state that can help to detect at‐risk individuals. Similarly, sensory changes, sleep and behavior disturbances, and frailty have been associated with higher risk of developing dementia. These clinical findings, together with the recognition that AD pathology precedes the diagnosis by many years, raises the possibility that non‐cognitive changes may be early and non‐invasive markers for AD or, even more provocatively, that treating non‐cognitive aspects may help to prevent or treat AD and related dementias.

Methods

A subcommittee of the Canadian Consensus Conference on Diagnosis and Treatment of Dementia reviewed areas of emerging evidence for non‐cognitive markers of dementia. We examined the literature for five non‐cognitive domains associated with future dementia: motor, sensory (hearing, vision, olfaction), neuro‐behavioral, frailty, and sleep. The Grading of Recommendations Assessment, Development, and Evaluation system was used to assign the strength of the evidence and quality of the recommendations. We provide recommendations to primary care clinics and to specialized memory clinics, answering the following main questions: (1) What are the non‐cognitive and functional changes associated with risk of developing dementia? and (2) What is the evidence that sensory, motor, behavioral, sleep, and frailty markers can serve as potential predictors of dementia?

Results

Evidence supported that gait speed, dual‐task gait speed, grip strength, frailty, neuropsychiatric symptoms, sleep measures, and hearing loss are predictors of dementia. There was insufficient evidence for recommending assessing olfactory and vision impairments as a predictor of dementia.

Conclusions

Non‐cognitive markers can assist in identifying people at risk for cognitive decline or dementia. These non‐cognitive markers may represent prodromal symptoms and several of them are potentially amenable to treatment that might delay the onset of cognitive decline.

Association of Late Life Depression, (Non-) Modifiable Risk and Protective Factors with Dementia and Alzheimer's Disease: Literature Review on Current Evidences, Preventive Interventions and Possible Future Trends in Prevention and Treatment of Dementia

The number of people living with dementia and Alzheimer’s disease is growing rapidly, making dementia one of the biggest challenges for this century. Many studies have indicated that depression plays an important role in development of dementia, including Alzheimer’s disease; depression, especially, during the late life may either increase the risk of dementia or even being its prodromal stage. Despite a notably large number of carried observational studies and/or clinical trials, the association between the late life depression and dementia remains, due to the complexity of their relationship, still unclear. Moreover, during past two decades multiple other (non-)modifiable risk and possibly protective factors such as the hypertension, social engagement, obesity, level of education or physical (in)activity have been identified and their relationship with the risk for development of dementia and Alzheimer’s disease has been extensively studied. It has been proposed that to understand mechanisms of dementia and Alzheimer’s disease pathogeneses require their multifactorial nature represented by these multiple factors to be considered. In this review, we first summarize the recent literature findings on roles of the late life depression and the other known (non-)modifiable risk and possibly protective factors in development of dementia and Alzheimer’s disease. Then, we provide evidences supporting hypotheses that (i) depressive syndromes in late life may indicate the prodromal stage of dementia (Alzheimer’s disease) and, (ii) the interplay among the multiple (non-)modifiable risk and protective factors should be considered to gain a better understanding of dementia and Alzheimer’s disease pathogeneses. We also discuss the evidences of recently established interventions considered to prevent or delay the prodromes of dementia and provide the prospective future directions in prevention and treatment of dementia and Alzheimer’s disease using both the single-domain and multidomain interventions.

Prevalence of Mild Behavioral Impairment and Risk of Dementia in a Psychiatric Outpatient Clinic

Background:

Mild behavioral impairment (MBI) has been proposed as risk factor for dementia, and for some, an early manifestation of dementia.

Objective:

We examined the prevalence of MBI in the psychiatric outpatient clinic, and compared the incidence of dementia in MBI with that in other psychiatric diseases.

Methods:

Retrospective chart review was conducted in 2,853 consecutive outpatients over the age of 50. MBI was diagnosed according to the International Society to Advance Alzheimer’s Research and Treatment research diagnostic criteria. The incidence rate of dementia was examined in the patients who were followed up for at least 1 month. Kaplan-Meier survival analyses and Cox proportional hazards regression models were performed to compare the time to onset of dementia between MBI and other psychiatric diseases.

Results:

The prevalence of MBI was 3.5% and the incidence of dementia was 30.7 cases per 1000 person-years. The hazard ratio (HR) for dementia was higher for MBI than other psychiatric diseases (HR: 8.07, 95% confidence interval: 4.34–15.03, p < 0.001). In MCI patients, the cumulative survival in MCI with affective dysregulation tended to be lower than that in MCI without (p = 0.090).

Conclusions:

Psychiatric outpatients often meet MBI criteria. MBI, especially the affective dysregulation domain, increases the risk of dementia in this psychiatric outpatient population. Since late-onset psychiatric and behavioral symptoms may be prodromal symptoms of dementia in some, careful observation is needed, and psychiatric clinicians should keep prodromal dementia on their differential diagnosis when assessing those with new onset psychiatric symptomatology in older adults.

Risk of dementia and death in very-late-onset schizophrenia-like psychosis: A national cohort study

Knowledge is limited regarding the risks of death and dementia in very-late onset schizophrenia-like psychosis (VLOS). This study aims to scrutinize the associations between VLOS with the risks of death and dementia. Based on a prospective Israeli cohort study with national coverage, 94,120 persons without dementia or schizophrenia diagnoses aged 60 to 90 in 2012 were followed-up for the risks of dementia or death from 2013 to 2017. VLOS was classified as present from the age of the first ICD-9 diagnosis during follow-up, otherwise as absent. Hazard ratios (HR) with confidence intervals (95% CI) were computed with survival models to quantify the associations between VLOS and the risks of death and dementia, without and with adjustment for confounding. Nine sensitivity analyses were computed to examine the robustness of the results. The group with VLOS, compared to the group without, had higher death (n = 61, 18.5% vs. n = 7028, 7.5%, respectively) and dementia (n = 64, 19.5% vs. n = 5962, 6.4%, respectively) rates. In the primary analysis, the group with VLOS compared to the group without had increased risks of death (unadjusted HR = 3.10, 95% CI = 2.36, 4.06, P < .001; adjusted HR = 2.89, 95% CI = 2.15, 3.89; P < .001) and dementia (unadjusted HR = 3.81, 95% CI = 2.90, 4.99, P < .001; adjusted HR = 2.67, 95% CI = 1.82, 3.91; P < .001). The results remained statistically significant (P < .05) in all sensitivity analyses, including among persons without antipsychotic medication. The results may support notions of increased dementia risk and accelerated aging in VLOS, or that VLOS is a prodromal state of dementia.

Oleanolic acid alleviates oxidative stress in Alzheimer's disease by regulating stanniocalcin-1 and uncoupling protein-2 signalling

Oxidative stress is thought to play an important role in the occurrence and development of Alzheimer's disease (AD) and antioxidants may delay or even treat AD. Oleanolic acid (OA) exhibits antioxidant properties against many diseases. However, its effects on oxidative stress in AD remain unclear. Here, we explored the role and mechanism of action of OA in N2a/APP695swe cells exposed to oxidative stress. The cells were incubated with different concentrations of OA (0, 5, 8, 10, 15, and 25 μmol/L) for 24 hours. Higher concentrations of OA (10, 15, and 25 μmol/L) significantly suppressed the apoptosis, caspase-3 activity, reactive oxygen species level, and β amyloid (Aβ) content and increased the viability of these cells. OA (10 μmol/L) also increased the expression of stanniocalcin-1 (STC-1) and uncoupling protein-2 (UCP2) in N2a/APP695swe cells. STC-1 interference markedly reversed the effect of OA on UCP2, indicating that OA may regulate UCP2 expression in N2a/APP695swe cells via STC-1. Moreover, UCP2 inhibition significantly reversed the OA-mediated effects on cell viability, caspase-3 activity, reactive oxygen species, and Aβ level. Thus, OA regulates UCP2 expression via STC-1 to alleviate oxidative stress and Aβ level in N2a/APP695swe cells.

Profile of mild behavioral impairment and factor structure of the Mild Behavioral Impairment Checklist in cognitively normal older adults

OBJECTIVES

In this large population study, we set out to examine the profile of mild behavioral impairment (MBI) by using the Mild Behavioral Impairment Checklist (MBI-C) and to explore its factor structure when employed as a self-reported and informant-rated tool.

DESIGN

This was a population-based cohort study.

SETTING

Participants were recruited from the Platform for Research Online to Investigate Genetics and Cognition in Aging study (https://www.protect-exeter.org.uk).

PARTICIPANTS

A total of 5,742 participant-informant dyads participated in the study.

MEASUREMENTS

Both participants and informants completed the MBI-C. The factor structure of the MBI-C was evaluated by exploratory factor analysis.

RESULTS

The most common MBI-C items, as rated by self-reported and informants, related to affective dysregulation (mood/anxiety symptoms), being present in 34% and 38% of the sample, respectively. The least common items were those relating to abnormal thoughts and perception (psychotic symptoms) (present in 3% and 6% of the sample, respectively). Only weak correlations were observed between self-reported and informant-reported MBI-C responses. Exploratory factor analysis for both sets of respondent answers indicated that a five-factor solution for the MBI-C was appropriate, reflecting the hypothesized structure of the MBI-C.

CONCLUSION

This is the largest and most detailed report on the frequency of MBI symptoms in a nondementia sample. The full spectrum of MBI symptoms was present in our sample, whether rated by self-reported or informant report. However, we show that the MBI-C performs differently in self-reported versus informant-reported situations, which may have important implications for the use of the questionnaire in clinic and research.

Metformin and Risk of Alzheimer's Disease Among Community-Dwelling People With Diabetes: A National Case-Control Study

CONTEXT

Type 2 diabetes has been linked with an increased risk of Alzheimer's disease (AD). Studies on the association between metformin use and AD have reported conflicting results.

OBJECTIVE

To investigate whether metformin use modifies the association between diabetes and incident, clinically verified AD.

DESIGN

Nested case-control study.

SETTING

All community-dwelling people in Finland.

PARTICIPANTS

Cases were all community-dwelling Finns with AD diagnosed from 2005 to 2011 and with diabetes diagnosed ≥ 3 years before AD (n = 9862). Cases were matched with up to 2 control persons by age, sex, and diabetes duration (n = 19 550).

MAIN OUTCOME MEASURE

Cumulative metformin exposure was determined from reimbursed dispensings over a 10- to 16-year period. Adjusted odds ratios (aORs) were calculated using conditional logistic regression to estimate associations, with adjustment for potential confounders.

RESULTS

A total of 7225 (73.3%) cases and 14528 (74.3%) controls received metformin at least once. Metformin use (ever use) was not associated with incident AD (aOR 0.99; 95% confidence interval [CI], 0.94-1.05). The adjusted odds of AD were lower among people dispensed metformin for ≥ 10 years (aOR 0.85; 95% CI, 0.76-0.95), those dispensed cumulative defined daily doses (DDDs) of < 1825-3650 (aOR 0.91; 95% CI, 0.84-0.98) and > 3650 DDDs (aOR 0.77; 95% CI, 0.67-0.88), and among persons dispensed an average of 2 g metformin daily (aOR 0.89; 95% CI, 0.82-0.96).

CONCLUSION

In this large national sample we found no evidence that metformin use increases the risk of AD. Conversely, long-term and high-dose metformin use was associated with a lower risk of incident AD in older people with diabetes.

Neuropsychiatric symptoms as predictors of conversion from MCI to dementia: a machine learning approach

OBJECTIVES

To use a Machine Learning (ML) approach to compare Neuropsychiatric Symptoms (NPS) in participants of a longitudinal study who developed dementia and those who did not.

DESIGN

Mann-Whitney U and ML analysis. Nine ML algorithms were evaluated using a 10-fold stratified validation procedure. Performance metrics (accuracy, recall, F-1 score, and Cohen's kappa) were computed for each algorithm, and graphic metrics (ROC and precision-recall curves) and features analysis were computed for the best-performing algorithm.

SETTING

Primary care health centers.

PARTICIPANTS

128 participants: 78 cognitively unimpaired and 50 with MCI.

MEASUREMENTS

Diagnosis at baseline, months from the baseline assessment until the 3rd follow-up or development of dementia, gender, age, Charlson Comorbidity Index, Neuropsychiatric Inventory-Questionnaire (NPI-Q) individual items, NPI-Q total severity, and total stress score and Geriatric Depression Scale-15 items (GDS-15) total score.

RESULTS

30 participants developed dementia, while 98 did not. Most of the participants who developed dementia were diagnosed at baseline with amnestic multidomain MCI. The Random Forest Plot model provided the metrics that best predicted conversion to dementia (e.g. accuracy=.88, F1=.67, and Cohen's kappa=.63). The algorithm indicated the importance of the metrics, in the following (decreasing) order: months from first assessment, age, the diagnostic group at baseline, total NPI-Q severity score, total NPI-Q stress score, and GDS-15 total score.

CONCLUSIONS

ML is a valuable technique for detecting the risk of conversion to dementia in MCI patients. Some NPS proxies, including NPI-Q total severity score, NPI-Q total stress score, and GDS-15 total score, were deemed as the most important variables for predicting conversion, adding further support to the hypothesis that some NPS are associated with a higher risk of dementia in MCI.

Exploring prior diseases associated with incident late-onset Alzheimer's disease dementia

Studies have identified prior conditions associated with late-onset Alzheimer's disease dementia (LOAD), but all prior diseases have rarely been screened simultaneously in the literature. Our objective in the present study was to identify prior conditions associated with LOAD and construct pathways for them. We conducted a population-based matched case-control study based on data collected in the National Health Insurance Research database of Taiwan and the Catastrophic Illness Certificate database for the years 1997-2013. Prior diseases definitions were based on the first three digits of the codes listed in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Inclusion criteria required that each ICD-code existed for at least 1 year and incurred at least 2 outpatient visits or inpatient diagnosis. The case group comprised 4,600 patients newly diagnosed with LOAD in 2007-2013. The LOAD patients were matched by sex and age to obtain 4,600 controls. Using stepwise multivariate logistic regression analysis, diseases were screened for 1, 2 …, 9 years prior to the first diagnosis of LOAD. Path analysis was used to construct pathways between prior diseases and LOAD. Our results revealed that the following conditions were positively associated with the incidence of LOAD: anxiety (ICD-code 300), functional digestive disorder (ICD code 564), psychopathology-specific symptoms (ICD-code 307), disorders of the vestibular system (ICD-code 386), concussion (ICD-code 850), disorders of the urethra and urinary tract (ICD-code 599), disorders of refraction and accommodation (ICD-code 367), and hearing loss (ICD-code 389). A number of the prior diseases have previously been described in the literature in a manner identical to that in the present study. Our study supports the assertion that mental, hearing, vestibular system, and functional digestive disorders may play an important role in the pathogenesis of LOAD.

Brain Metabolic Dysfunction in Early Neuropsychiatric Symptoms of Dementia

Neuropsychiatric symptoms (NPS) including behavioral and psychiatric symptoms are common in the dementia stages of Alzheimer's disease (AD) and are associated with poorer outcomes in cognition, functional states, quality of life, and accelerated progression to severe dementia or death. NPS are also increasingly observed in the mild cognitive impairment stage of AD and may predict incipient dementia. As such, there is an emerging conceptual framework, which support NPS as early non-cognitive symptoms of dementia. [18F]fluorodeoxyglucosepositron emission tomography is a technique that is sensitive in detecting resting metabolism associated with NPS in neuropsychiatric conditions, and there is a growing body of literature evaluating the role of NPS as early indicators of brain metabolic dysfunctions in AD. In this mini-review, we examine the frequency and associations of NPS with metabolic dysfunction in the AD continuum, including preclinical, prodromal, and dementia stages of AD. We will also present the validated neurobehavioral syndrome, mild behavioral impairment describes the later life emergence of sustained NPS as an at-risk state for incident cognitive decline and dementia, and an early presentation of neurodegenerative diseases in some. Lastly, we will discuss future directions in the field so as to better understand the neurobiological basis of NPS in the early stages of the AD continuum, and their role in predicting AD pathophysiological progression and incident dementia.

Antiepileptic Drug Use and the Risk of Stroke Among Community-Dwelling People With Alzheimer Disease: A Matched Cohort Study

Background People with Alzheimer disease ( AD ) are more predisposed to seizures than older people in general, and use of antiepileptic drugs ( AED s) is more frequent. AED use has been linked to a higher risk of vascular events in the general population; however, it is not evident whether the same risk exists in people with AD . We assessed the risk of stroke associated with incident AED use among people with AD . Methods and Results The MEDALZ (Medication Use and Alzheimer's Disease) cohort includes all Finnish people who received a clinically verified AD diagnosis (N=70718) from 2005 to 2011. People with previous strokes were excluded. For each incident AED user (n=5617) one nonuser was matched according to sex, age, and time since AD diagnosis. Analyses were conducted with Cox proportional hazards models and inverse probability of treatment weighting. Compared with nonuse, AED use was associated with an increased risk of stroke (inverse probability of treatment weighting hazard ratio ( HR ), 1.37; 95% confidence interval [CI], 1.07-1.74). The risk was strongest during the first 90 days (adjusted HR , 2.36; 95% CI , 1.25-4.47) of AED use. According to stroke type, the association was with ischemic strokes (inverse probability of treatment weighting HR , 1.34; 95% CI , 1.00-1.79) and hemorrhagic ones (inverse probability of treatment weighting HR , 1.44; 95% CI , 0.86-2.43). The stroke risk of users of older AED s did not differ from that of the users of newer AED s (adjusted HR , 1.04; 95% CI , 0.71-1.53). Conclusions AED use was related to an increased risk of stroke, regardless of AED type. Our results highlight caution in AED use in this vulnerable population.

Accumulation of Hospital Days Among Antipsychotic Initiators With Alzheimer's Disease

OBJECTIVES

To compare the accumulation of hospital days, a proposed proxy for overall drug safety, between antipsychotic initiators and noninitiators with Alzheimer's disease (AD).

DESIGN

Nationwide exposure-matched cohort.

SETTING AND PARTICIPANTS

Finnish community dwellers who received an incident AD diagnosis in 2005‒2011 (n = 70,718). For each antipsychotic initiator, 1 noninitiator was matched on age, sex, and time since AD diagnosis (n = 19,909 matched pairs).

MEASURES

Accumulation of hospital days was measured during a 2-year follow-up from the national hospital discharge register. Antipsychotic use was ascertained from the National Prescription Register. Association between antipsychotic initiation and accumulation of hospital days was analyzed using negative binomial model.

RESULTS

During the 2-year follow-up, antipsychotic initiators were hospitalized on average for 52.5 (standard deviation 97.7) days and matched noninitiators for 34.7 (standard deviation 72.4) days. Of antipsychotic initiators 23.8% and of noninitiators, 34.1% did not have any hospital days. Antipsychotic initiators had 53% more hospital days (adjusted incidence rate ratio 1.53; 95% confidence interval 1.47‒1.59) than noninitiators. Strongest associations were observed during the first 6 months. Antipsychotic initiators had more hospital days with primary diagnosis codes of dementia; mental and behavioral disorders; factors influencing health status; diseases of the respiratory, genitourinary, and circulatory system; certain infectious and parasitic diseases; and symptoms not elsewhere classified, than noninitiators.

CONCLUSIONS AND IMPLICATIONS

Antipsychotic initiators accumulated more hospital days than noninitiators, especially within the first 6 months after initiation. This may indicate adverse events or difficulties in treating the most severe behavioral and psychological symptoms of dementia and health problems triggering them. After initiating antipsychotics, careful and regular monitoring is needed to assess response and decrease the risk of adverse effects and events.

Anxiety as a risk factor of Alzheimer's disease and vascular dementia

BACKGROUND

The aetiology of dementia is not yet fully understood. Stress can have a damaging effect on brain health. The prognostic effect of anxiety is still unclear regarding Alzheimer's disease as well as vascular dementia.AimsTo explore the association between anxiety and future dementia.

METHOD

Medline, PsycINFO, CINAHL, Web of Science and ALOIS were searched for publications up to 12 January 2018. Longitudinal studies with a follow-up of at least 2 years were included, if the trait or state anxiety had been assessed at baseline. Studies with cognitive impairment at baseline were not included. We used a random effects model to calculate the pooled time to Alzheimer's disease and incidence of vascular dementia.

RESULTS

Anxiety predicts risk of Alzheimer's disease (n = 26 193 out of seven studies, hazard ratio1.53, 95% CI 1.16-2.01, P < 0.01) and vascular dementia (n = 4916 out of two studies, odds ratio1.88, 95% CI 1.05-3.36, P < 0.01). The pooled hazard ratio regarding risk of Alzheimer's disease was still significant when excluding studies with critical risk of bias (n = 14 110 out of six studies, hazard ratio 1.35, 95% CI 1.08-1.70, P < 0.01).

CONCLUSIONS

Anxiety is a risk factor for both types of dementia. The temporal and functional relation between anxiety and dementia needs investigation in future studies. The protective value of treating anxiety should be explored further.Declaration of interestNone.

Proton pump inhibitor use and risk of hip fractures among community-dwelling persons with Alzheimer's disease-a nested case-control study

BACKGROUND

Hip fractures are a major health concern among older persons with Alzheimer's disease, who usually use many concomitant drugs for several diseases. Evidence of the association between proton pump inhibitor use and risk of hip fracture is contradictory.

AIM

To investigate whether the long-term use of proton pump inhibitor is associated with risk of hip fractures among community-dwelling persons with Alzheimer's disease.

METHODS

In this nested case-control study, the nationwide MEDALZ data were utilised. Community-dwelling persons with Alzheimer's disease who encountered incident hip fracture (N = 4818; mean age 84.1) were included as cases. Four controls were matched for each case at the date of hip fracture (N = 19 235; mean age 84.0). The association between hip fracture and duration of current PPI use (ongoing use during 0-30 days before the index date), and cumulative duration of use during 10 years before was investigated with conditional logistic regression.

RESULTS

Long-term or cumulative proton pump inhibitor use was not associated with an increased risk of hip fracture. Current proton pump inhibitor use was associated with an increased risk of hip fracture (adjusted OR 1.12, 95% CI 1.03-1.22). The risk was increased in short-term current use (<1 year) (adjusted OR 1.23, 95% CI 1.10-1.37).

CONCLUSIONS

The increased risk of hip fracture was evident only in short-term proton pump inhibitor use, but no association was found for long-term or cumulative use. Thus, our findings do not support previous assumptions that long-term proton pump inhibitor use would be associated with an increased risk of hip fractures.

Dementia clinical trial implications of mild behavioral impairment

The World Alzheimer Report 2016 estimated that 47 million people are living with dementia worldwide (Alzheimer's Disease International, 2016). In the inaugural World Health Organization Ministerial Conference on Global Action against Dementia, six of the top ten research priorities were focused on prevention, identification, and reduction of dementia risk, and on delivery and quality of care for people with dementia and their carers (Shah et al., 2016). While the Lancet Neurology Commission has suggested that even minor advances to delay progression or ameliorate symptoms might have substantial financial and societal benefits (Winblad et al., 2016), advances have been slow.

Case series of mild behavioral impairment: toward an understanding of the early stages of neurodegenerative diseases affecting behavior and cognition

Mild behavioral impairment (MBI) is characterized by later life acquired, sustained, and impactful neuropsychiatric symptoms (NPS) of any severity that cannot be better accounted for by other formal medical and psychiatric nosology. MBI is an "at risk" state for incident cognitive decline and dementia, and for some, MBI is the index manifestation of neurodegeneration, observed in advance of cognitive impairment. Initially described in Frontotemporal Dementia (FTD), MBI evolved to describe a preclinical stage of all cause dementia, and has been operationalized in the International Society to Advance Alzheimer's Research and Treatment-Alzheimer's Association (ISTAART-AA) proposed research diagnostic criteria. Here, we describe three cases in which patients diagnosed with a variety of dementing conditions initially presented with NPS to the Cognitive Neurosciences Clinic at the University of Calgary, Canada. All patients described in our series were given a final diagnosis of dementia; the etiology supported by clinical, cognitive, and neuroimaging findings. In all three cases, the progression to dementia was preceded by NPS that meet criteria for MBI. With these examples, we are able to illustrate that MBI can represent a premonitory stage of dementia of different etiologies. These cases demonstrate early use of the MBI checklist (MBI-C). The cases presented in this series serve as examples of NPS as early manifestations of dementia. Our case examples include both FTD and AD, and demonstrate that before a diagnosis of a neurodegenerative disease is considered, often patients will be diagnosed with and treated for a psychiatric condition. These early NPS can be characterized within the domains outlined in the ISTAART-AA MBI criteria, and detected with the MBI-C, which may help clinicians consider neurodegenerative disease in the differential diagnosis of later life onset psychiatric symptomatology.

Affective and emotional dysregulation as pre-dementia risk markers: exploring the mild behavioral impairment symptoms of depression, anxiety, irritability, and euphoria

BACKGROUND

Affective and emotional symptoms such as depression, anxiety, euphoria, and irritability are common neuropsychiatric symptoms (NPS) in pre-dementia and cognitively normal older adults. They comprise a domain of Mild Behavioral Impairment (MBI), which describes their emergence in later life as an at-risk state for cognitive decline and dementia, and as a potential manifestation of prodromal dementia. This selective scoping review explores the epidemiology and neurobiological links between affective and emotional symptoms, and incident cognitive decline, focusing on recent literature in this expanding field of research.

METHODS

Existing literature in prodromal and dementia states was reviewed, focusing on epidemiology, and neurobiology. Search terms included: "mild cognitive impairment," "dementia," "prodromal dementia," "preclinical dementia," "Alzheimer's," "depression," "dysphoria," "mania," "euphoria," "bipolar disorder," and "irritability."

RESULTS

Affective and emotional dysregulation are common in preclinical and prodromal dementia syndromes, often being harbingers of neurodegenerative change and progressive cognitive decline. Nosological constraints in distinguishing between pre-existing psychiatric symptomatology and later life acquired NPS limit historical data utility, but emerging research emphasizes the importance of addressing time frames between symptom onset and cognitive decline, and age of symptom onset.

CONCLUSION

Affective symptoms are of prognostic utility, but interventions to prevent dementia syndromes are limited. Trials need to assess interventions targeting known dementia pathology, toward novel pathology, as well as using psychiatric medications. Research focusing explicitly on later life onset symptomatology will improve our understanding of the neurobiology of NPS and neurodegeneration, enrich the study sample, and inform observational and clinical trial design for prevention and treatment strategies.

Schizophrenia and risk of dementia: a meta-analysis study

BACKGROUND

Evidence suggests that schizophrenia may be associated with an increased risk of dementia, but results from prior studies have been inconsistent. This study aimed to estimate the relationship between schizophrenia and incident dementia using a quantitative meta-analysis.

METHODS

Several databases were used to gather relevant information, including PubMed, Embase, and Web of Science, with the publication date of articles limited up to December 23, 2017. All studies reported a multivariate-adjusted estimate, represented as relative risk (RR) with 95% confidence intervals (CIs), for the association between schizophrenia and risk of dementia incidence. Pooled RRs were calculated using a random-effects model.

RESULTS

Six studies met our inclusion criteria for this meta-analysis, which included 206,694 cases of dementia and 5,063,316 participants. All individuals were without dementia at baseline. Overall, the quantitative meta-analysis suggested that subjects with schizophrenia were associated with a significantly greater risk of dementia incidence (RR 2.29; 95% CI 1.35-3.88) than those without.

CONCLUSION

The results of this meta-analysis indicate that individuals with schizophrenia may have an increased risk for the development of dementia. Future studies should explore whether schizophrenia is a modifiable risk factor for dementia.

Depressive Symptoms Are Associated with Cognitive Function in the Elderly with Type 2 Diabetes

BACKGROUND

Type 2 diabetes (T2D) is a metabolic condition associated with poor clinical and cognitive outcomes including vascular disease, depressive symptoms, cognitive impairment, and dementia. In the general elderly population, depression has been consistently identified as a risk factor for cognitive impairment/decline. However, the association between depression and cognitive function in T2D has been understudied.

OBJECTIVE

We investigated the association between depression and cognitive function in a large sample of cognitively normal elderly with T2D.

METHODS

In this cross-sectional study, we examined 738 participants, aged 65-88 years old, enrolled in the Israel Diabetes and Cognitive Decline study. For each cognitive domain (Episodic Memory, Executive Function, Attention/Working Memory, Language/Semantic Categorization) and Overall Cognition, multiple linear regressions assessed its association with depression (score greater than 5 on the 15-item version of the Geriatric Depression Scale [GDS]), adjusting for age, sex, and education.

RESULTS

Depression (n = 66, 8.9%) was associated with worse performance on tasks of Executive Function (p = 0.004), Language/Semantic Categorization (p < 0.001), and Overall Cognition (p < 0.002), but not Episodic Memory (p = 0.643) or Attention/Working Memory (p = 0.488). Secondary analyses using GDS as a continuous variable did not substantially change the results. Adjusting also for a history of antidepressant medication use slightly weakened the findings.

CONCLUSION

Significant associations of depression with several cognitive domains and Overall Cognition even in cognitively normal elderly with T2D, suggest that depression may have a role in impaired cognitive function in T2D, which may be attenuated by antidepressants.