Trajectory of cognitive decline as a predictor of psychosis in early Alzheimer disease in the cardiovascular health study

Factors associated with cognitive function in patient with Alzheimer's disease with newly prescribed acetylcholinesterase inhibitors: A 1-year retrospective cohort study

Objective

We aimed to examine the factors associated with treatment outcomes in patients with Alzheimer's disease (AD) after 1 year of acetylcholinesterase inhibitors (AChEI) treatment.

Method

We obtained electronic medical records from a medical center in Southern Taiwan between January 2015 and September 2021. Participants aged ≥60 who were newly diagnosed with AD and had been prescribed AChEIs were included. Cognitive assessments were performed before the AChEIs were prescribed and at the 1 year follow-up. Cognition progressors were defined as a Mini-Mental State Examination decline of >3 or a Clinical Dementia Rating decline of ≥1 after 1 year of AChEI treatment. The relationship between the baseline characteristics and cognitive status after follow-up was investigated using logistic regression analysis after adjusting for potential confounders.

Results

A total of 1370 patients were included in our study (mean age, 79.86 ± 8.14 years). After adjustment, the body mass index (BMI) was found to be significantly lower in the progressor group [adjusted odds ratio (AOR): 0.970, 95% confidence intervals (95% CIs): 0.943 to 0.997, P = 0.033]. The usage of antipsychotics was significantly higher in the progressor group (AOR: 1.599, 95% CIs: 1.202 to 2.202, P = 0.001). The usage of benzodiazepine receptor agonists also tended to be significantly higher in the progressor group (AOR: 1.290, 95% CIs: 0.996 to 1.697, p = 0.054).

Conclusion

These results suggest that patients with AD who receive 1 year of AChEI treatment and have a lower BMI or concurrent treatment with antipsychotics and benzodiazepine receptor agonists are more likely to suffer from cognitive decline.

Unveiling the Enigma: Exploring Risk Factors and Mechanisms for Psychotic Symptoms in Alzheimer's Disease through Electronic Medical Records with Deep Learning Models

Around 50% of patients with Alzheimer's disease (AD) may experience psychotic symptoms after onset, resulting in a subtype of AD known as psychosis in AD (AD + P). This subtype is characterized by more rapid cognitive decline compared to AD patients without psychosis. Therefore, there is a great need to identify risk factors for the development of AD + P and explore potential treatment options. In this study, we enhanced our deep learning model, DeepBiomarker, to predict the onset of psychosis in AD utilizing data from electronic medical records (EMRs). The model demonstrated superior predictive capacity with an AUC (area under curve) of 0.907, significantly surpassing conventional risk prediction models. Utilizing a perturbation-based method, we identified key features from multiple medications, comorbidities, and abnormal laboratory tests, which notably influenced the prediction outcomes. Our findings demonstrated substantial agreement with existing studies, underscoring the vital role of metabolic syndrome, inflammation, and liver function pathways in AD + P. Importantly, the DeepBiomarker model not only offers a precise prediction of AD + P onset but also provides mechanistic understanding, potentially informing the development of innovative treatments. With additional validation, this approach could significantly contribute to early detection and prevention strategies for AD + P, thereby improving patient outcomes and quality of life.

Targeting the post-synaptic proteome has therapeutic potential for psychosis in Alzheimer Disease

Individuals with Alzheimer Disease who develop psychotic symptoms (AD + P) experience more rapid cognitive decline and have reduced indices of synaptic integrity relative to those without psychosis (AD-P). We sought to determine whether the postsynaptic density (PSD) proteome is altered in AD + P relative to AD-P, analyzing PSDs from dorsolateral prefrontal cortex of AD + P, AD-P, and a reference group of cognitively normal elderly subjects. The PSD proteome of AD + P showed a global shift towards lower levels of all proteins relative to AD-P, enriched for kinases, proteins regulating Rho GTPases, and other regulators of the actin cytoskeleton. We computationally identified potential novel therapies predicted to reverse the PSD protein signature of AD + P. Five days of administration of one of these drugs, the C-C Motif Chemokine Receptor 5 inhibitor, maraviroc, led to a net reversal of the PSD protein signature in adult mice, nominating it as a novel potential treatment for AD + P.

Aberrant Dopamine System Function in the Ferrous Amyloid Buthionine (FAB) Rat Model of Alzheimer's Disease

Antipsychotics increase the risk of death in elderly patients with Alzheimer's disease (AD). Thus, there is an immediate need for novel therapies to treat comorbid psychosis in AD. Psychosis has been attributed to a dysregulation of the dopamine system and is associated with aberrant regulation by the hippocampus. Given that the hippocampus is a key site of pathology in AD, we posit that aberrant regulation of the dopamine system may contribute to comorbid psychosis in AD. A ferrous amyloid buthionine (FAB) rodent model was used to model a sporadic form of AD. FAB rats displayed functional hippocampal alterations, which were accompanied by decreases in spontaneous, low-frequency oscillations and increases in the firing rates of putative pyramidal neurons. Additionally, FAB rats exhibited increases in dopamine neuron population activity and augmented responses to the locomotor-inducing effects of MK-801, as is consistent with rodent models of psychosis-like symptomatology. Further, working memory deficits in the Y-maze, consistent with an AD-like phenotype, were observed in FAB rats. These data suggest that the aberrant hippocampal activity observed in AD may contribute to dopamine-dependent psychosis, and that the FAB model may be useful for the investigation of comorbid psychosis related to AD. Understanding the pathophysiology that leads to comorbid psychosis in AD will ultimately lead to the discovery of novel targets for the treatment of this disease.

Behavioral and Psychological Symptoms of Dementia: Prevalence, Symptom Severity, and Caregiver Distress in South-Western Uganda-A Quantitative Cross-Sectional Study

The purpose of the study was to investigate behavioral and psychological symptoms (BPSD) prevalence, severity, and distress experienced by caregivers of people living with dementia (PLWD). A cross-sectional, population-based study was conducted in a rural area in southwestern Uganda. A Neuropsychiatric Inventory Questionnaire (NPI-Q) was used to determine the presence of BPSD as perceived by caregivers of PLWD. We carried out both descriptive and inferential data analysis. A total of 175 caregivers of PLWD were enrolled in this study. Among PLWD, 99% had presented BPSD in the past month. Hallucinations (75%) and dysphoria/depression (81%) were the two BPSD that occurred most frequently. Most participants (70%) stated that PLWD experienced hallucinations of significant severity. Aberrant motor activity was reported by 60% of the participants as the type of BPSD that caused severe distress. There was a high positive correlation (0.82) between the total severity score and total distress scores. Interventions aimed at addressing dysphoria and hallucinations may be essential for the reduction of caregiver distress. These findings point to the need for promoting early screening for BPSDs and the provision of support to caregivers.

Testing the Reliability and Validity of the Revised Care Plan Checklist for Evidence of Person-Centered Care Approaches for Behavioral and Psychological Symptoms of Distress in Persons With Dementia

The Checklist for Evidence of Person-Centered Care Approaches for Behavioral and Psychological Symptoms of Distress (BPSD) in Care Plans was developed to assess the person-centeredness of care plans for nursing home residents living with behavioral and psychological symptoms associated with dementia. The purpose of the current study was to evaluate the reliability and validity of a revised version of the Checklist. Data from a larger randomized clinical trial testing the implementation of the Evidence of Integration Triangle for BPSD were used. One hundred seventy-nine care plans for 103 residents were examined. Descriptive statistics, Rasch analysis, and inter-rater reliability were used. The Checklist demonstrated evidence of inter-rater reliability and validity based on model fit and acceptable INFIT and OUTFIT statistics. This study serves as pilot work for future Checklist use and validation efforts on a larger scale. Findings encourage a discourse on the inclusion of BPSD and person-centered approaches in care plans for those living with dementia. [Research in Gerontological Nursing, xx(x), xx-xx.].

Pathogenesis and Personalized Interventions for Pharmacological Treatment-Resistant Neuropsychiatric Symptoms in Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common form of dementia, with cognitive impairment as a core symptom. Neuropsychiatric symptoms (NPSs) also occur as non-cognitive symptoms during the disease course, worsening the prognosis. Recent treatment guidelines for NPSs have recommended non-pharmacological treatments as the first line of therapy, followed by pharmacological treatments. However, pharmacological treatment for urgent NPSs can be difficult because of a lack of efficacy or an intolerance, requiring multiple changes in psychotropic prescriptions. One biological factor that might be partly responsible for this difficulty is structural deterioration in elderly people with dementia, which may cause a functional vulnerability affecting the pharmacological response. Other causative factors might include awkward psychosocial interpersonal relations between patients and their caregiver, resulting in distressful vicious circles. Overlapping NPS sub-symptoms can also blur the prioritization of targeted symptoms. Furthermore, consistent neurocognitive reductions cause a primary apathy state and a secondary distorted ideation or perception of present objects, leading to reactions that cannot be treated pharmacologically. The present review defines treatment-resistant NPSs in AD; it may be necessary and helpful for clinicians to discuss the pathogenesis and comprehensive solutions based on three major hypothetical pathophysiological viewpoints: (1) biology, (2) psychosociology, and (3) neurocognition.

Psychosis as a Treatment Target in Dementia: A Roadmap for Designing Interventions

Psychotic phenomena are among the most severe and disruptive symptoms of dementias and appear in 30% to 50% of patients. They are associated with a worse evolution and great suffering to patients and caregivers. Their current treatments obtain limited results and are not free of adverse effects, which are sometimes serious. It is therefore crucial to develop new treatments that can improve this situation. We review available data that could enlighten the future design of clinical trials with psychosis in dementia as main target. Along with an explanation of its prevalence in the common diseases that cause dementia, we present proposals aimed at improving the definition of symptoms and what should be included and excluded in clinical trials. A review of the available information regarding the neurobiological basis of symptoms, in terms of pathology, neuroimaging, and genomics, is provided as a guide towards new therapeutic targets. The correct evaluation of symptoms is transcendental in any therapeutic trial and these aspects are extensively addressed. Finally, a critical overview of existing pharmacological and non-pharmacological treatments is made, revealing the unmet needs, in terms of efficacy and safety. Our work emphasizes the need for better definition and measurement of psychotic symptoms in dementias in order to highlight their differences with symptoms that appear in non-dementing diseases such as schizophrenia. Advances in neurobiology should illuminate the development of new, more effective and safer molecules for which this review can serve as a roadmap in the design of future clinical trials.

Using Telemedicine to Assess and Manage Psychosis in Neurodegenerative Diseases in Long-Term Care

The coronavirus disease 2019 (COVID-19) epidemic has forced a sudden global implementation of telemedicine strategies, including in long-term care (LTC) facilities where many people with dementia and Parkinson disease (PD) reside. Telemedicine offers a unique set of advantages for residents in LTC facilities if effectively supported and implemented, including expanded access to specialists in rural or underserved areas or for people with dementia who cannot travel for off-site visits. Many medical and psychiatric organizations have recently issued new or updated guidelines on the use of telemedicine. On October 22, 2020, a multidisciplinary consensus panel was convened to collate a list of best practices for LTC facilities and specialists when conducting telemedicine with residents with dementia-related psychosis or PD-related psychosis (PDP). A collaborative effort between specialists, facility administrators, and facility staff is essential for the success of telemedicine in the LTC setting. Telemedicine in LTC facilities comes with increased administrative and technical challenges that fall heavily on the shoulders of the LTC facility administrators and staff. Specialists can ease this burden by maintaining flexibility and ensuring expression of empathy and thanks to the staff who are facilitating the visits. LTC staff can provide specialists with valuable information about their patients to aid in evaluation and diagnosis. Specialists can facilitate this exchange of information by speaking to staff who work closely with the resident about any signs of hallucinations or delusions they may have observed. Educational efforts can increase staff understanding of dementia and PDP and empower them to engage with, and facilitate the resident's treatment plan. Using these strategies to take advantage of the benefits of telemedicine, specialists and LTC staff can together expand and improve care for LTC facility residents with dementia-related psychosis or PDP.

Relapse in Dementia-related Psychosis and Clinical Decisions

Patients with dementia can experience hallucinations and delusions because of their underlying neurodegenerative condition, a syndrome known as dementia-related psychosis. Dementia-related psychosis contributes to morbidity and mortality among patients with dementia and increases the burden on caregivers and the health care system. With no pharmacological treatment currently approved in the United States for this condition, patients are often treated off-label with antipsychotics. Though typical and atypical antipsychotics have demonstrated variable to modest efficacy in dementia-related psychosis, serious safety concerns arise with their use. Accordingly, clinical and Centers for Medicare & Medicaid Services guidelines recommend trying antipsychotics only when other therapies have failed and encourage treatment discontinuation of antipsychotics after 4 months to assess whether ongoing therapy is needed. Discontinuation of effective antipsychotic treatment, however, may increase the risk for relapse of symptoms and the associated morbidities that accompany relapse. A randomized medication withdrawal clinical trial design allows assessment of relapse risk after discontinuation and can provide initial information on longer-term safety of therapy for dementia-related psychosis. Given the substantial unmet need in this condition, new, well-tolerated therapies that offer acute and sustained reduction of symptoms while also preventing recurrence of symptoms of psychosis are critically needed.

Increased retention of tau PET ligand [18F]-AV1451 in Alzheimer's Disease Psychosis

Psychosis in Alzheimer's disease (AD) represents a distinct disease subtype with a more rapid progression of illness evidenced by an increased velocity of cognitive decline and a hastened mortality. Previous biomarker and post-mortem studies have implicated tau neuropathology as a possible mediator of the accelerated decline in AD psychosis. Tau positron emission tomography (PET) neuroimaging provides the opportunity to evaluate tau pathology in-vivo, so that clinical symptomatology can be correlated with disease pathology. [¹⁸F]-AV1451 (Flortaucipir) is a PET ligand with high affinity for insoluble paired-helical filaments (PHFs) of hyperphosphorylated tau. In order to determine whether the development of psychosis and worsened prognosis in AD is associated with an increased burden of tau pathology that can be identified with tau imaging, we identified subjects within the Alzheimer's disease neuroimaging initiative (ADNI) who had [¹⁸F]-AV1451 imaging at baseline and became psychotic over the course of the study (N = 17) and matched them 1:3 for gender, age, and education to subjects who had [¹⁸F]-AV1451 imaging at baseline and did not become psychotic (N = 50). We compared baseline [¹⁸F]-AV1451 retention, in addition to cognitive and functional baseline and longitudinal change, in those who became psychotic over the course of participation in ADNI with those who did not. Results suggest that increases in tau pathology in frontal, medial temporal, and occipital cortices, visualized with [¹⁸F]-AV1451 binding, are associated with psychosis and a more rapid cognitive and functional decline.

The Role of Decreased Cortical Thickness and Volume of Medial Temporal Lobe Structures in Predicting Incident Psychosis in Patients With Alzheimer's Disease: A Prospective Longitudinal MRI Study

OBJECTIVE

To investigate the effect of decreased cortical thickness or volume of medial temporal lobe structures on the risk of incident psychosis in patients with AD.

DESIGN, SETTING, AND PARTICIPANTS

This hospital-based prospective longitudinal study enrolled 109 patients with AD. All patients with AD were evaluated at 3-month intervals to investigate the effect of decreased cortical thickness or volume of medial temporal lobe structures on the risk of incident psychosis in patients with AD.

OUTCOME MEASURE

The main outcome measure was time-to-progression from AD to incident psychosis. The thickness or volume of medial temporal lobe structures (i.e., the hippocampus, entorhinal cortex, and parahippocampus) were measured using magnetic resonance imaging and the Freesurfer automated segmentation pipeline at baseline.

RESULTS

Multivariate Cox proportional hazards regression analysis revealed that a decreased cortical thickness or volume of medial temporal region was associated with a higher risk of incident psychosis in patients with AD. The hazard ratios for decreased cortical thickness of the left entorhinal cortex and decreased cortical volume of the right hippocampus were 4.291 (95% confidence interval [CI], 1.196-15.384) and 2.680 [(CI, 1.003-1.196]), respectively.

CONCLUSION

Our study revealed that decreased cortical thickness or volume of medial temporal sub-regions is a risk factor for incident psychosis in patients with AD. A careful assessment of the thickness or volume of the medial temporal lobe structures in AD may improve early detection and intervention of psychosis in AD.

Heterogeneity in Alzheimer's Disease Diagnosis and Progression Rates: Implications for Therapeutic Trials

The clinical presentation and the pathological processes underlying Alzheimer's disease (AD) can be very heterogeneous in severity, location, and composition including the amount and distribution of AB deposition and spread of neurofibrillary tangles in different brain regions resulting in atypical clinical patterns and the existence of distinct AD variants. Heterogeneity in AD may be related to demographic factors (such as age, sex, educational and socioeconomic level) and genetic factors, which influence underlying pathology, the cognitive and behavioral phenotype, rate of progression, the occurrence of neuropsychiatric features, and the presence of comorbidities (e.g., vascular disease, neuroinflammation). Heterogeneity is also manifest in the individual resilience to the development of neuropathology (brain reserve) and the ability to compensate for its cognitive and functional impact (cognitive and functional reserve). The variability in specific cognitive profiles and types of functional impairment may be associated with different progression rates, and standard measures assessing progression may not be equivalent for individual cognitive and functional profiles. Other factors, which may govern the presence, rate, and type of progression of AD, include the individuals' general medical health, the presence of specific systemic conditions, and lifestyle factors, including physical exercise, cognitive and social stimulation, amount of leisure activities, environmental stressors, such as toxins and pollution, and the effects of medications used to treat medical and behavioral conditions. These factors that affect progression are important to consider while designing a clinical trial to ensure, as far as possible, well-balanced treatment and control groups.

Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.

Efficacy and safety of pharmacotherapy for Alzheimer's disease and for behavioural and psychological symptoms of dementia in older patients with moderate and severe functional impairments: a systematic review of controlled trials

BACKGROUND

Many patients with Alzheimer's disease (AD) are physically frail or have substantial functional impairments. There is growing evidence that such patients are at higher risk for medication-induced adverse events. Furthermore, frailty seems to be more predictive of poor clinical outcomes than chronological age alone. To our knowledge, no systematic review of clinical trials examining drug therapy of AD or behavioural and psychological symptoms of dementia (BPSD) has specifically focused on the topic of physical frailty. Our objective was to evaluate the efficacy and safety of pharmacotherapy in AD patients with frailty or significant functional impairments.

METHODS

We performed a systematic literature search in MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) for randomized controlled trials (RCTs) of drug therapy of AD and BPSD in patients with significant functional impairments according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and Cochrane research criteria. Significant functionally impaired patient populations were identified using the recommendations of the Medication and Quality of Life in frail older persons (MedQoL) Research Group. Screening, selection of studies, data extraction and risk of bias assessment were performed independently by two reviewers. Outcomes including functional status, cognitive function, changes in BPSD symptoms, clinical global impression and quality of life were analysed. For assessing harm, we assessed adverse events, drop-outs as a proxy for treatment tolerability and death. Results were analysed according to Cochrane standards and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Of 45,045 search results, 38,447 abstracts and 187 full texts were screened, and finally, 10 RCTs were included in the systematic review. Selected articles evaluated pharmacotherapy with acetylcholinesterase-inhibitors (AChEI), anticonvulsants, antidepressants and antipsychotics. Studies of AChEIs suggested that patients with significant functional impairments had slight but significant improvements in cognition and that AChEIs were generally well tolerated. Studies of antidepressants did not show significant improvements in depressive symptoms. Antipsychotics and anticonvulsants showed small effects on some BPSD items but also higher rates of adverse events. However, due to the very small number of identified trials, the quality of evidence for all outcomes was low to very low. Overall, the small number of eligible studies demonstrates that significantly functional impaired older patients have not been adequately taken into consideration in most clinical trials investigating drug therapy of AD and BPSD.

CONCLUSION

Due to lack of evidence, it is not possible to give specific recommendations for drug therapy of AD and BSPD in frail older patients or older patients with significant functional impairments. Therefore, clinical trials focussing on frail older adults are urgently required. A standardized approach to physical frailty in future clinical studies is highly desirable.

Rationale, Design, and Methodology of a Prospective Cohort Study for Coping with Behavioral and Psychological Symptoms of Dementia: The RECage Project

BACKGROUND

Behavioral and psychological symptoms of dementia (BPSD) are quite challenging problems during the dementia course. Special Care Units for people with dementia (PwD) and BPSD (SCU-B) are residential medical structures, where BPSD patients are temporarily admitted, in case of unmanageable behavioral disturbances at home.

OBJECTIVE

RECage (REspectful Caring for AGitated Elderly) aspires to assess the short and long-term effectiveness of SCU-Bs toward alleviating BPSD and improving the quality of life (QoL) of PwD and their caregivers.

METHODS

RECage is a three-year, prospective study enrolling 500 PwD. Particularly, 250 community-dwelling PwDs presenting with severe BPSD will be recruited by five clinical centers across Europe, endowed with a SCU-B, for a short period of time; a second similar group of 250 PwD will be followed by six other no-SCU-B centers solely via outpatient visits. RECage's endpoints include short and long-term SCU-B clinical efficacy, QoL of patients and caregivers, cost-effectiveness of the SCU-B, psychotropic drug consumption, caregivers' attitude toward dementia, and time to nursing home placement.

RESULTS

PwD admitted in SCU-Bs are expected to have diminished rates of BPSD and better QoL and their caregivers are also expected to have better QoL and improved attitude towards dementia, compared to those followed in no-SCU-Bs. Also, the cost of care and the psychotropic drug consumption are expected to be lower. Finally, PwD followed in no-SCU-Bs are expected to have earlier admission to nursing homes.

CONCLUSION

The cohort study results will refine the SCU-B model, issuing recommendations for implementation of SCU-Bs in the countries where they are scarce or non-existent.

Psychosis in Alzheimer's Disease

PURPOSE OF REVIEW

To review the incidence, treatment and genetics of psychosis in people with mild cognitive impairment (MCI) and Alzheimer's disease (AD).

RECENT FINDINGS

Psychosis in Alzheimer's disease (AD) has an incidence of ~ 10% per year. There is limited evidence regarding psychological interventions. Pharmacological management has focused on atypical antipsychotics, balancing modest benefits with evidence of long-term harms. The 5HT2A inverse agonist pimavanserin appears to confer benefit in PD psychosis with initial evidence of benefit in AD. Cholinesterase inhibitors give modest benefits in DLB psychosis. The utility of muscarinic agonists, lithium, glutamatergic and noradrenergic modulators needs further study. Recent work has confirmed the importance of psychosis in MCI as well as AD. The lack of evidence regarding psychological therapies is an urgent knowledge gap, but there is encouraging evidence for emerging pharmacological treatments. Genetics will provide an opportunity for precision medicine and new treatment targets.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

Effects of Vitamin D Use on Outcomes of Psychotic Symptoms in Alzheimer Disease Patients

OBJECTIVE

To identify medications that may prevent psychosis in patients with Alzheimer disease (AD).

METHODS

The authors compared the frequency of medication usage among patients with AD with or without psychosis symptoms (AD + P versus AD - P). The authors also conducted survival analysis on time to psychosis for patients with AD to identify drugs with beneficial effects. The authors further explored the potential molecular mechanisms of identified drugs by gene-signature analysis. Specifically, the gene expression profiles induced by the identified drug(s) were collected to derive a list of most perturbed genes. These genes were further analyzed by the associations of their genetic variations with AD or psychosis-related phenotypes.

RESULTS

Vitamin D was used more often in AD - P patients than in AD + P patients. Vitamin D was also significantly associated with delayed time to psychosis. AD and/or psychosis-related genes were enriched in the list of genes most perturbed by vitamin D, specifically genes involved in the regulation of calcium signaling downstream of the vitamin D receptor.

CONCLUSION

Vitamin D was associated with delayed onset of psychotic symptoms in patients with AD. Its mechanisms of action provide a novel direction for development of drugs to prevent or treat psychosis in AD. In addition, genetic variations in vitamin D-regulated genes may provide a biomarker signature to identify a subpopulation of patients who can benefit from vitamin D treatment.

Gray Matter Changes Associated With the Development of Delusions in Alzheimer Disease

OBJECTIVE

Delusions affect approximately a third of Alzheimer disease (AD) patients and are associated with poor outcomes. Previous studies investigating the neuroanatomic correlates of delusions have yet to reach a consensus, with findings of reduced volume across all lobes, particularly in frontal regions. The current study examined the gray matter (GM) differences associated with delusions in AD.

METHODS

Using voxel-based morphometry, we assessed GM in 23 AD patients who developed delusions (AD+D) and 36 comparable AD patients who did not (AD-D) at baseline and follow-up. Analysis of variance was used to identify consistent differences between AD+D and AD-D patients across time points (main effect of group), consistent changes from baseline to follow-up (main effect of time), and differential changes between AD+D and AD-D over time (interaction of group and time). All data were obtained from the National Alzheimer's Coordinating Center database.

RESULTS

The AD+D group had consistently lower frontal GM volume, although both groups showed decreased GM in frontotemporal brain regions over time. An interaction was observed between delusions and longitudinal change, with AD+D patients having significantly elevated GM in predominantly temporal areas at baseline assessment, becoming significantly lower than the AD-D group at follow-up.

CONCLUSION

These findings suggest that, there are specific volumetric markers that distinguish patients with delusions from those without, before, and after the onset of delusions. Specifically, the decline of GM in temporal areas that had elevated levels prior to the onset of delusions may be involved in the manifestation of delusions.

The course of neuropsychiatric symptoms in nursing home residents from admission to 30-month follow-up

Aim

The aim of this study was to describe the prevalence and persistence of clinically significant neuropsychiatric symptoms (NPS) in nursing home residents with dementia, and to study the association between severity of dementia and specific neuropsychiatric sub-syndromes over time.

Methods

In total, 583 residents with dementia were included at admission to a nursing home and followed with biannual assessments until death, or to 30-month follow-up. At the end of the 30-month follow-up, 305 participants had died and 57 had left the study for other reasons, leaving 221 residents in the study. We collected data on demographics, cognition, severity of dementia, NPS, personal activities of daily living (P-ADL), physical health, medication and type of nursing home unit. NPS was assessed using the Neuropsychiatric Inventory (NPI), the Nursing Home version.

Results

The prevalence and persistence at two consecutive time-points of clinically significant NPS was high during the study period. The mean NPI agitation sub-syndrome score increased during the study period, while the NPI affective and psychosis sub-syndrome scores remained unchanged. More severe dementia was associated with higher NPI agitation, psychosis and affective sub-syndrome scores. The association remained unchanged over time for agitation and psychosis. For the NPI affective sub-syndrome, the association was stronger at the beginning, and declined towards the end of the study period.

Conclusion

The findings of high prevalence and persistence at two consecutive time points of clinically significant NPS over time, and the associations between severity of dementia and NPI sub-syndromes shed light on the burden and care needs of nursing home residents with dementia after admission to nursing home care. This information is of interest to health care planners and providers to enable them to increase the quality of care for nursing home residents.

Genetic risk for schizophrenia and psychosis in Alzheimer disease

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD), affecting ~40 to 60% of individuals with AD (AD with psychosis (AD+P)). In comparison with AD subjects without psychosis, AD+P subjects have more rapid cognitive decline and poor outcomes. Prior studies have estimated the heritability of psychosis in AD at 61%, but the underlying genetic sources of this risk are not known. We evaluated a Discovery Cohort of 2876 AD subjects with (N=1761) or without psychosis (N=1115). All subjects were genotyped using a custom genotyping array designed to evaluate single-nucleotide polymorphisms (SNPs) with evidence of genetic association with AD+P and include SNPs affecting or putatively affecting risk for schizophrenia and AD. Results were replicated in an independent cohort of 2194 AD subjects with (N=734) or without psychosis (N=1460). We found that AD+P is associated with polygenic risk for a set of novel loci and inversely associated with polygenic risk for schizophrenia. Among the biologic pathways identified by the associations of schizophrenia SNPs with AD+P are endosomal trafficking, autophagy and calcium channel signaling. To the best of our knowledge, these findings provide the first clear demonstration that AD+P is associated with common genetic variation. In addition, they provide an unbiased link between polygenic risk for schizophrenia and a lower risk of psychosis in AD. This provides an opportunity to leverage progress made in identifying the biologic effects of schizophrenia alleles to identify novel mechanisms protecting against more rapid cognitive decline and psychosis risk in AD.

Psychosis and dementia: risk factor, prodrome, or cause?

BACKGROUND

Progression of dementia is often associated with the emergence of neuropsychiatric symptoms (NPS), though there is recent evidence that NPS may occur in prodromal dementia (PrD) and impact clinical course. Mood and anxiety symptoms are the NPS that tend to occur most frequently in PrD and thus have been most extensively studied. Comparatively, there has been little focus on psychotic symptoms in PrD.

METHODS

The authors review the existing literature on psychosis in PrD, including the functional psychosis of early and late onset, with a focus on epidemiology, phenomenology, and clinical course and treatment considerations.

RESULTS

Patients with psychotic disorders at baseline such as schizophrenia may be more at risk for developing dementia over time, although this is not completely clear. Psychotic symptoms are likely more common in PrD than previously understood based on factor analysis studies, although they are much more common in established dementia. Variability in findings may reflect the heterogeneous nature of PrD studies to date and the lack of inclusion of patients with late onset psychosis in most clinical studies. The presence of psychosis in patients with PrD may be associated with a worse prognosis in terms of mortality and conversion to dementia.

CONCLUSIONS

Research to date suggests that psychosis in PrD may be more common than previously thought and impact clinical course negatively. Future studies incorporating patients with late onset psychotic disorders, and focusing on the impact of early recognition and treatment, are required to more fully understand the role of psychosis in PrD.

Association Between Psychosis Phenotype and APOE Genotype on the Clinical Profiles of Alzheimer's Disease

BACKGROUND

Psychosis is a common phenomenon in Alzheimer's disease (AD). The APOE ε4 allele is the strongest genetic risk factor for the development of AD, but its association with psychosis remains unclear.

OBJECTIVE

We investigated the associations between psychosis, subdivided into delusions and hallucinations, as well as APOE ε4 allele on cognitive and functional outcomes. Secondarily, we investigated the associations between APOE ε4, Lewy bodies, and psychosis.

METHODS

Data from the National Alzheimer's Coordinating Center (NACC) were used. Nine hundred patients with a confirmed diagnosis of AD based on the NIA-AA Reagan were included in the analysis. Global cognition was assessed using the Mini-Mental State Exam (MMSE) and functional status was assessed using the Functional Activities Questionnaire (FAQ). Psychosis status was determined using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Factorial design was used to assess the effects of psychosis and APOE ε4, as well as their interaction.

RESULTS

Psychosis and the presence of APOE ε4 were both associated with lower MMSE scores, while only psychosis was associated with higher FAQ scores. Furthermore, patients with hallucinations had lower MMSE and higher FAQ scores than patients with only delusions. There was a significant interaction effect between psychosis and APOE ε4 on MMSE scores, with APOE ε4 negatively affecting patients with hallucinations-only psychosis. APOE ε4 was positively associated with the presence of Lewy body pathology, and both were found to be more prevalent in psychotic patients, with a stronger association with hallucinations.

CONCLUSION

Psychosis in AD was associated with greater cognitive and functional impairments. Patients with hallucinations-with or without delusions-conferred even greater deficits compared to patients with only delusions. The APOE ε4 allele was associated with worse cognition, especially for patients with hallucination-only psychosis. APOE ε4 may mediate cognitive impairment in the hallucinations phenotype through the development of Lewy bodies. Our findings support that subtypes of psychosis should be evaluated separately.

Neuropsychiatric Disturbances in Alzheimer's Disease: What Have We Learned from Neuropathological Studies?

Neuropsychiatric symptoms (NPS) are an integral part of the dementia syndrome and were therefore recently included in the core diagnostic criteria of dementia. The near universal prevalence of NPS in Alzheimer's disease (AD), combined with their disabling effects on patients and caregivers, is contrasted by the fact that few effective and safe treatments exist, which is in part to be attributed to our incomplete understanding of the neurobiology of NPS. In this review, we describe the pathological alterations typical for AD, including spreading and evolution of burden, effect on the molecular and cellular integrity, functional consequences and atrophy of NPS-relevant brain regions and circuits in correlation with specific NPS assessments. It is thereby clearly established that NPS are fundamental expressions of the underlying neurodegenerative brain disease and not simply reflect the patients' secondary response to their illness. Neuropathological studies, moreover, include a majority of end-stage patient samples, which may not correctly represent the pathophysiological environment responsible for particular NPS that may already be present in an early stage, or even prior to AD diagnosis. The burdensome nature and high prevalence of NPS, in combination with the absence of effective and safe pharmacotherapies, provide a strong incentive to continue neuropathological and neurochemical, as well as imaging and other relevant approaches to further improve our apprehension of the neurobiology of NPS.

Trajectories of dementia-related cognitive decline in a large mental health records derived patient cohort

BACKGROUND

Modeling trajectories of decline can help describe the variability in progression of cognitive impairment in dementia. Better characterisation of these trajectories has significant implications for understanding disease progression, trial design and care planning.

METHODS

Patients with at least three Mini-mental State Examination (MMSE) scores recorded in the South London and Maudsley NHS Foundation Trust Electronic Health Records, UK were selected (N = 3441) to form a retrospective cohort. Trajectories of cognitive decline were identified through latent class growth analysis of longitudinal MMSE scores. Demographics, Health of Nation Outcome Scales and medications were compared across trajectories identified.

RESULTS

Four of the six trajectories showed increased rate of decline with lower baseline MMSE. Two trajectories had similar initial MMSE scores but different rates of decline. In the faster declining trajectory of the two, a higher incidence of both behavioral problems and sertraline prescription were present.

CONCLUSIONS

We find suggestive evidence for association of behavioral problems and sertraline prescription with rate of decline. Further work is needed to determine whether trajectories replicate in other datasets.

Neuropsychiatric Symptoms in Mild Cognitive Impairment

OBJECTIVE

Neuropsychiatric symptoms (NPS) may be the first manifestation of an underlying neurocognitive disorder. We undertook a review to provide an update on the epidemiology and etiological mechanisms of NPS that occur in mild cognitive impairment (MCI) and just before the onset of MCI. We discuss common clinical presentations and the implications for diagnosis and care.

METHOD

The authors conducted a selective review of the literature regarding the emergence of NPS in late life, before and after the onset of MCI. We discuss recent publications that explore the epidemiology and etiological mechanisms of NPS in the earliest clinical stages of these disorders.

RESULTS

NPS have been reported in 35% to 85% of adults with MCI and also occur in advance of cognitive decline. The occurrence of NPS for the first time in later life should increase suspicion for an underlying neurocognitive disorder. The presenting symptom may provide a clue regarding the etiology of the underlying disorder, and the co-occurrence of NPS may herald a more accelerated cognitive decline.

CONCLUSIONS

NPS are prevalent in the early clinical stages of neurocognitive disorders and can serve as both useful diagnostic and prognostic indicators. Recognition of NPS as early manifestations of neurocognitive disorders will become increasingly important as we move towards preventative strategies and disease-modifying treatments that may be most effective when deployed in the earliest stages of disease.

Risk Factors, Neuroanatomical Correlates, and Outcome of Neuropsychiatric Symptoms in Alzheimer's Disease

BACKGROUND

An integrative model of neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) is lacking.

OBJECTIVE

In this study, we investigated the risk factors, anatomy, biology, and outcomes of NPS in AD.

METHODS

181 subjects were included from the Alzheimer's Disease Neuroimaging Study (ADNI). NPS were assessed with the Neuropsychiatric Inventory Questionnaire at baseline and 6 months. NPI >3 was used as a threshold for NPS positivity. Three NPS courses were characterized: 1) minimal/absent (negative at 0 and 6 months, n = 77); 2) fluctuating (positive only at one time point, n = 53); 3) persistent (positive at both time points, n = 51). We examined the association between NPS course and family history of dementia, personal history of psychiatric disorders, cerebrospinal fluid biomarkers, atrophy patterns, as well as longitudinal cognitive and functional measures at 12 and 24 months (MMSE, CDR-SOB, FAQ).

RESULTS

AD subjects with absent, fluctuating, or persistent NPS had similar CSF amyloid-β and tau levels. AD subjects with minimal/absent NPS had less personal history of psychiatric disorders (35%) than those with fluctuating (57%; p = 0.015) or persistent NPS (47%, not significant). At 24 months, AD subjects with persistent NPS had worse cognitive (MMSE; p = 0.05) and functional (CDR-SOB; p = 0.016) outcomes. Dorsolateral prefrontal atrophy was seen in persistent NPS, but not in fluctuating NPS.

CONCLUSIONS

Our results suggest that individuals with personal history of psychiatric disorders might be more vulnerable to develop NPS throughout the course of AD. The worst cognitive and functional outcomes associated with NPS in AD underscores the importance of monitoring NPS early in the disease course.

Incident Psychosis in Subjects With Mild Cognitive Impairment or Alzheimer's Disease

OBJECTIVE

To estimate the incidence of psychotic symptoms in Alzheimer's disease.

METHODS

The study consists of 776 elderly subjects presenting to the Alzheimer Disease Research Center at the University of Pittsburgh (Pittsburgh, Pennsylvania) between May 9, 2000, and August 19, 2014. All participants were diagnosed with mild cognitive impairment (National Institute on Aging-Alzheimer's Association workgroup criteria) or possible or probable Alzheimer's disease (National Institute of Neurologic and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association criteria) and were without psychosis at entry. Psychotic symptoms were evaluated using the Consortium to Establish a Registry for Alzheimer's Disease Behavioral Rating Scale every 6 months. One-, 3- and 5-year cumulative incidences of psychosis were calculated.

RESULTS

The 1-year psychosis incidence was 10% (95% CI, 8%-12%), and this annual rate remained remarkably consistent at 3 and 5 years. Psychosis incidence was related to cognitive status at all time points. However, the incidence rate reached a plateau during the disease course. Cumulative psychosis incidence at 5 years was 61% (95% CI, 52%-69%) in individuals with moderate to severe Alzheimer's disease, not statistically significantly different from the cumulative incidence at 3 years in this group, which was 48% (95% CI, 40%-55%) or from the 5-year incidence in individuals who entered the study with mild Alzheimer's disease, which was 48% (95% CI, 41%-56%).

CONCLUSIONS

Psychosis in Alzheimer's disease has been associated with a number of adverse clinical outcomes. We provide estimates of the risk of psychosis onset within clinically defined subgroups of individuals, a tool clinicians can use in treatment planning. Anticipating which subjects are at high risk for psychosis and the poor outcomes associated with it can help with family education and support decisions to implement nonpharmacologic strategies that may reduce or prevent symptoms.

Slowing the progression of Alzheimer's disease; what works?

Alzheimer's disease (AD) is an age-related progressive dementia, which is increasing in prevalence world-wide. Typically affecting short-term memory at onset, this devastating illness advances to impair all aspects of cognition, as well as non-cognitive domains. Although much effort has been made in recent years to develop disease-modifying treatments, medications which provided promising results in pre-clinical research have so far faltered in human clinical trials. Attention has recently shifted into trying to identify preventative measures that may delay the onset of the illness. Preventative factors include physical activity, proper diet, cognitive stimulation and the management of conditions such as hypertension, diabetes and obesity. However, it remains imperative to identify approaches that may help patients already diagnosed with the illness. Alongside pharmacological research, much work has been done on uncovering strategies which may slow down the progression of AD. This review aims to summarize evidence supporting or refuting methods impacting on the progression of the disease. AD remains a chronic and serious condition, therefore any intervention delaying the onset of moderate/severe symptoms will have a significant impact on patients and their families.

More evidence for association of a rare TREM2 mutation (R47H) with Alzheimer's disease risk

Over 20 risk loci have been identified for late-onset Alzheimer's disease (LOAD), most of which display relatively small effect sizes. Recently, a rare missense (R47H) variant, rs75932628 in TREM2, has been shown to mediate LOAD risk substantially in Icelandic and Caucasian populations. Here, we present more evidence for the association of the R47H with LOAD risk in a Caucasian population comprising 4567 LOAD cases and controls. Our results show that carriers of the R47H variant have a significantly increased risk for LOAD (odds ratio = 7.40, p = 3.66E-06). In addition to Alzheimer's disease risk, we also examined the association of R47H with Alzheimer's disease-related phenotypes, including age-at-onset, psychosis, and amyloid deposition but found no significant association. Our results corroborate those of other studies implicating TREM2 as an LOAD risk locus and indicate the need to determine its biological role in the context of neurodegeneration.

The monoaminergic footprint of depression and psychosis in dementia with Lewy bodies compared to Alzheimer's disease

Introduction

Depression and psychosis are two of the most severe neuropsychiatric symptoms (NPS) in dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD). Both NPS have negative effects on cognitive performance and life expectancy. The current study aimed to investigate and compare monoaminergic etiologies between both neurodegenerative conditions, given the lack of an efficient pharmacological treatment until present.

Methods

Eleven behaviorally relevant brain regions of the left frozen hemisphere of 10 neuropathologically confirmed AD patients with/without depression (AD + D/-D; 5 were psychotic within AD + D), 10 confirmed DLB patients, all of whom were depressed (DLB + D; 5 psychotic patients), and, finally, 10 confirmed control subjects were regionally dissected. All patients were retrospectively assessed before death using the Behavioral Pathology in Alzheimer’s Disease Rating Scale (Behave-AD) and Cornell Scale for Depression in Dementia amongst others. The concentrations of dopamine (DA), serotonin (5-HT), (nor)adrenaline and respective metabolites, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), 5-hydroxy-3-indoleacetic acid (5-HIAA), and, 3-methoxy-4-hydroxyphenylglycol (MHPG), were determined using reversed-phase high-performance liquid chromatography with electrochemical detection.

Results

DLB subjects had the overall lowest monoamine and metabolite concentrations regarding 33 out of 41 significant monoaminergic group alterations. Moreover, MHPG levels were significantly decreased in almost 8 out of 11 brain regions of DLB- compared to AD patients. We also observed the lowest 5-HT and 5-HIAA levels, and 5-HIAA/5-HT turnover ratios in DLB + D compared to AD + D subjects. Additionally, a 4- and 7-fold increase of DOPAC/DA and HVA/DA turnover ratios, and, a 10-fold decrease of thalamic DA levels in DLB + D compared to AD + D patients and control subjects was noticed. Regarding psychosis, hippocampal DA levels in the overall DLB group significantly correlated with Behave-AD AB scores. In the total AD group, DA levels and HVA/DA ratios in the amygdala significantly correlated with Behave-AD AB scores instead.

Conclusions

Monoaminergic neurotransmitter alterations contribute differently to the pathophysiology of depression and psychosis in DLB as opposed to AD, with a severely decreased serotonergic neurotransmission as the main monoaminergic etiology of depression in DLB. Similarly, psychosis in DLB might, in part, be etiologically explained by dopaminergic alterations in the hippocampus, whereas in AD, the amygdala might be involved.

Hyperphosphorylated tau is elevated in Alzheimer's disease with psychosis

Psychosis occurs in 40-60% of Alzheimer's disease (AD) subjects, is heritable, and indicates a more rapidly progressive disease phenotype. Neuroimaging and postmortem evidence support an exaggerated prefrontal cortical synaptic deficit in AD with psychosis. Microtubule-associated protein tau is a key mediator of amyloid-β-induced synaptotoxicity in AD, and differential mechanisms of progressive intraneuronal phospho-tau accumulation and interneuronal spread of tau aggregates have recently been described. We hypothesized that psychosis in AD would be associated with greater intraneuronal concentration of phospho-tau and greater spread of tau aggregates in prefrontal cortex. We therefore evaluated prefrontal cortex phospho-tau in a cohort of 45 AD cases with and without psychosis. Intraneuronal phospho-tau concentration was higher in subjects with psychosis, while a measure of phospho-tau spread, volume fraction, was not. Across groups both measures were associated with lower scores on the Mini-Mental State Examination and Digit Span Backwards test. These novel findings indicate that tau phosphorylation may be accelerated in AD with psychosis, indicating a more dynamic, exaggerated pathology in AD with psychosis.

Pharmacodynamics, pharmacokinetics, safety, and tolerability of encenicline, a selective α7 nicotinic receptor partial agonist, in single ascending-dose and bioavailability studies

PURPOSE

Encenicline (EVP-6124) is a selective α7 nicotinic acetylcholine receptor partial agonist being developed for cognitive impairment in Alzheimer's disease and schizophrenia. We report on 2 single-dose studies to assess the relative bioavailability, pharmacokinetic profile, tolerability, and cognitive effects of encenicline in healthy volunteers.

METHODS

A single ascending-dose study assessed the safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of encenicline in healthy male volunteers. Subjects received a single 1-, 3.5-, 7-, 20-, 60-, or 180-mg oral solution dose of encenicline or placebo. A second single-dose, randomized, open-label, 3-period, crossover study in healthy male and female subjects compared the relative bioavailability of a 1-mg oral capsule versus a 1-mg oral solution dose of encenicline and evaluated the effects of food and sex on encenicline pharmacokinetic profile.

FINDINGS

In the first study, encenicline was well tolerated and dose-proportional increases in C(max) (mean range 0.59-100 ng/mL) and AUC0-∞ (mean range 45.6-8890 ng·h/mL) were observed over a 1- to 180-mg dose range. Procognitive effects on the Digit Symbol Substitution Test were maximal at the 20-mg dose. In the second study, encenicline 1-mg oral capsules and oral solution were bioequivalent and there was no observed food effect on encenicline pharmacokinetic profile with the 90% confidence intervals of the treatment ratios for both comparisons (ie, capsule to solution and fed to fasted) for Cmax and AUC being within 80% to 125%. A 30% to 40% higher encenicline exposure in female subjects than respective values in male subjects was consistent with a 33% higher weight of the male subjects. No clinically relevant safety profile or tolerability effects of encenicline were observed.

IMPLICATIONS

Encenicline was well tolerated at single doses up to 180 mg, and doses as low as 1 mg had dose- and time-dependent pharmacodynamic effects on the central nervous system. Oral capsule and solution were bioequivalent and were not affected by food. Although a sex effect on pharmacokinetic profile was observed, it was attributable to weight differences. Clinical Trial Registration at EudraCT: 2006-005623-42 and EudracT: 2008-000029-20.

Psychotic Alzheimer's disease is associated with gender-specific tau phosphorylation abnormalities

Converging evidence suggests that psychotic Alzheimer's disease (AD + P) is associated with an acceleration of frontal degeneration, with tau pathology playing a primary role. Previous histopathologic and biomarker studies have specifically implicated tau pathology in this condition. To precisely quantify tau abnormalities in the frontal cortex in AD + P, we used a sensitive biochemical assay of total tau and 4 epitopes of phospho-tau relevant in AD pathology in a postmortem sample of AD + P and AD - P. Samples of superior frontal gyrus from 26 AD subjects without psychosis and 45 AD + P subjects with psychosis were analyzed. Results of enzyme-linked immunosorbent assay demonstrate that AD + P females, but not males, had significantly higher levels of phosphorylated tau in the frontal cortex. In males, but not females, AD + P was associated with the presence of α-synuclein pathology. These results support a gender dissociation of pathology in AD + P. The design of future studies aimed at the elucidation of cognitive and/or functional outcomes; regional brain metabolic deficits; or genetic correlates of AD + P should take gender into consideration.

Pathogenic tau species drive a psychosis-like phenotype in a mouse model of Alzheimer's disease

Psychotic Alzheimer's disease (AD+P) is a rapidly progressive variant of AD associated with an increased burden of frontal tau pathology that affects up to 50% of those with AD, and is observed more commonly in females. To date, there are no safe and effective medication interventions with an indication for treatment in this condition, and there has been only very limited exploration of potential animal models for pre-clinical drug development. Pathogenic tau is over represented in the frontal cortex in AD+P, especially in females. In order to develop a candidate animal model of AD+P, we employed a tau mouse model with a heavy burden of frontal tau pathology, the rTg(tauP301L)4510 mouse, hereafter termed rTg4510. We explored deficits of prepulse inhibition of acoustic startle (PPI), a model of psychosis in rodents, and the correlation between pathogenic phospho-tau species associated with AD+P and PPI deficits in female mice. We found that female rTg4510 mice exhibit increasing PPI deficits relative to littermate controls from 4.5 to 5.5 months of age, and that these deficits are driven by insoluble fractions of the phospho-tau species pSer396/404, pSer202, and pThr231 found to be associated with human AD+P. This preliminary data suggests the utility of the rTg4510 mouse as a candidate disease model of human female AD+P. Further work expanded to include both genders and other behavioral outcome measures relevant to AD+P is necessary.

TAR DNA-binding protein 43 pathology in Alzheimer's disease with psychosis

BACKGROUND

TAR DNA-binding protein 43 (TDP-43) has been identified as a major disease protein in frontotemporal lobar degeneration. More recently, TDP-43 proteinopathy has also been observed in Alzheimer's disease (AD) with a characteristic distribution of TDP-43 predominantly in the mesial temporal lobe, and to a lesser degree in the neocortical areas. AD subjects with psychotic symptoms (AD+P) represent a subgroup characterized by greater impairment of frontal cortex-dependent cognitive functions and more severe frontal cortical neuropathology. The aim of this study is to determine whether there is an association between TDP-43 pathology and AD+P. We hypothesized that TDP-43 pathology would be more frequent in AD+P than in AD without psychosis.

METHODS

We studied the presence and distribution of TDP-43 pathology by immunohistochemistry in the dentate gyrus (DG) and prefrontal cortex (FC) of postmortem brain specimens from 68 subjects with a primary neuropathologic diagnosis of AD as determined by the Neuropathology Core of the University of Pittsburgh Alzheimer's Disease Research Center.

RESULTS

Forty-five (66%) subjects were classified as AD+P. Fourteen (20.6%) subjects had TDP-43 pathology in DG, eight (11.8%) had TDP-43 pathology in FC, and six (8.8%) had TDP-43 pathology in both regions. TDP-43 in DG was not significantly associated with AD+P. However, TDP-43 in FC demonstrated a trend toward reduced likelihood of psychosis (p = 0.068). TDP-43 pathology in DG, but not FC, was significantly associated with greater age at death and longer duration of illness.

CONCLUSIONS

Our findings indicate that there was no association between concomitant TDP-43 pathology in DG or FC and AD+P.

Abnormal kalirin signaling in neuropsychiatric disorders

Changes in dendritic spines structure and function play a critical role in a number of physiological processes, including synaptic transmission and plasticity, and are intimately linked to cognitive function. Alterations in dendritic spine morphogenesis occur in a number of neuropsychiatric disorders and likely underlie the cognitive and behavioral changes associated with these disorders. The neuronal guanine nucleotide exchange factor (GEF) kalirin is emerging as a key regulator of structural and functional plasticity at dendritic spines. Moreover, a series of recent studies have genetically and functionally linked kalirin signaling to several disorders, including schizophrenia and Alzheimer's disease. Kalirin signaling may thus represent a disease mechanism and provide a novel therapeutic target.

Psychosis in Alzheimer's disease

Psychotic symptoms, delusions and hallucinations, occur in approximately 50% of individuals with Alzheimer's disease (AD) (AD with psychosis [AD + P]). Pharmacotherapies for AD + P have limited efficacy and can increase short-term mortality. These observations have motivated efforts to identify the underlying biology of AD + P. Psychosis in AD indicates a more severe phenotype, with more rapid cognitive decline beginning even before psychosis onset. Neuroimaging studies suggest that AD + P subjects demonstrate greater cortical synaptic impairments than AD subjects without psychosis, reflected in reduced gray matter volume, reduced regional blood flow, and reduced regional glucose metabolism. Neuroimaging and available postmortem evidence further indicate that the impairments in AD + P, relative to AD subjects without psychosis, are localized to neocortex rather than medial temporal lobe. Neuropathologic studies provide consistent evidence of accelerated accumulation of hyperphosphorylated microtubule associated protein tau in AD + P. Finally, studies of familial aggregation of AD + P have established that the risk for psychosis in AD is, in part, genetically mediated. Although no genes are established as associated with AD + P, the first genome-wide association study of AD + P has generated some promising leads. The study of the neurobiology of AD + P is rapidly accelerating and may be poised for translational discovery. This process can be enhanced by identifying points of convergence and divergence with the neurobiology of AD proper and of schizophrenia, by innovative extension of current approaches, and by development of relevant animal models.

Cognitive reserve in young and old healthy subjects: differences and similarities in a testing-the-limits paradigm with DSST

Cognitive reserve (CR) is understood as capacity to cope with challenging conditions, e.g. after brain injury or in states of brain dysfunction, or age-related cognitive decline. CR in elderly subjects has attracted much research interest, but differences between healthy older and younger subjects have not been addressed in detail hitherto. Usually, one-time standard individual assessments are used to characterise CR. Here we observe CR as individual improvement in cognitive performance (gain) in a complex testing-the-limits paradigm, the digit symbol substitution test (DSST), with 10 repeated measurements, in 140 younger (20–30 yrs) and 140 older (57–74 yrs) healthy subjects. In addition, we assessed attention, memory and executive function, and mood and personality traits as potential influence factors for CR. We found that both, younger and older subjects showed significant gains, which were significantly correlated with speed of information processing, verbal short-term memory and visual problem solving in the older group only. Gender, personality traits and mood did not significantly influence gains in either group. Surprisingly about half of the older subjects performed at the level of the younger group, suggesting that interindividual differences in CR are possibly age-independent. We propose that these findings may also be understood as indication that one-time standard individual measurements do not allow assessment of CR, and that the use of DSST in a testing-the-limits paradigm is a valuable assessment method for CR in young and elderly subjects.

Optimal treatment of Alzheimer's disease psychosis: challenges and solutions

Psychotic symptoms emerging in the context of neurodegeneration as a consequence of Alzheimer's disease was recognized and documented by Alois Alzheimer himself in his description of the first reported case of the disease. Over a quarter of a century ago, in the context of attempting to develop prognostic markers of disease progression, psychosis was identified as an independent predictor of a more-rapid cognitive decline. This finding has been subsequently well replicated, rendering psychotic symptoms an important area of exploration in clinical history taking - above and beyond treatment necessity - as their presence has prognostic significance. Further, there is now a rapidly accreting body of research that suggests that psychosis in Alzheimer's disease (AD+P) is a heritable disease subtype that enjoys neuropathological specificity and localization. There is now hope that the elucidation of the neurobiology of the syndrome will pave the way to translational research eventuating in new treatments. To date, however, the primary treatments employed in alleviating the suffering caused by AD+P are the atypical antipsychotics. These agents are approved by the US Food and Drug Administration for the treatment of schizophrenia, but they have only marginal efficacy in treating AD+P and are associated with troubling levels of morbidity and mortality. For clinical approaches to AD+P to be optimized, this syndrome must be disentangled from other primary psychotic disorders, and recent scientific advances must be translated into disease-specific therapeutic interventions. Here we provide a review of atypical antipsychotic efficacy in AD+P, followed by an overview of critical neurobiological observations that point towards a frontal, tau-mediated model of disease, and we suggest a new preclinical animal model for future translational research.

Psychosis of Alzheimer disease: prevalence, incidence, persistence, risk factors, and mortality

OBJECTIVES

To establish the prevalence, incidence, persistence, risk factors, and mortality risk increase of psychosis of Alzheimer disease (PoAD) in a clinical sample.

DESIGN, PARTICIPANTS, AND MEASUREMENTS

Cross-sectional, observational study of 491 patients with probable AD who, at baseline visit, were evaluated with the Cambridge Examination for Mental Disorders of the Elderly, the Neuropsychiatric Inventory-10, the Rapid Disability Rating Scale-2, and the Zarit Burden Interview. All participants were reevaluated at 6, 12, 18, and 24 months. PoAD diagnoses were made using specific criteria.

RESULTS

PoAD prevalence was 7.3%, and the cumulative incidence at 6, 12, 18, and 24 months was 5.8%, 10.6%, 13.5%, and 15.1%, respectively. After 1 year, psychotic symptoms persisted in 68.7% of the patients with initial PoAD. At baseline, patients with PoAD scored lower in the Cambridge Cognitive Examination and Mini-Mental State Examination and higher in the Rapid Disability Rating Scale-2 and Zarit Burden Interview tests. Both low scores in the Cambridge Cognitive Examination subscale of learning memory (hazard ratio [HR] = 0.874; 95% CI: 0.788-0.969; Wald χ2 = 6.515; df = 1) and perception (HR = 0.743; 95% CI: 0.610-0.904; Wald χ2 = 8.778; df = 1), and high scores in expressive language (HR = 1.179; 95% CI: 1.024-1.358; Wald χ2 = 5.261; df = 1) and calculation skills (HR = 1.763; 95% CI: 1.067-2.913; Wald χ2 = 4.905; df = 1) were found to be associated with PoAD. PoAD leads to a faster functional impairment, and it increases mortality risk (HR = 2.191; 95% CI: 1.136-4.228; Wald χ2 = 5.471; df = 1) after controlling for age, gender, cognitive and functional disability, general health status, and antipsychotic treatment.

CONCLUSIONS

PoAD seems to define a phenotype of AD of greater severity, with worsened functional progression and increased mortality risk.

Behavioral symptoms related to cognitive impairment

Neuropsychiatric symptoms (NPS) are core features of Alzheimer's disease and related dementias. On one hand, behavioral symptoms in patients with mild cognitive impairment (MCI) can indicate an increased risk of progressing to dementia. On the other hand, mild behavioral impairment (MBI) in patients who usually have normal cognition indicates an increased risk of developing dementia. Whatever the cause, all dementias carry a high rate of NPI. These symptoms can be observed at any stage of the disease, may fluctuate over its course, are a leading cause of stress and overload for caregivers, and increase rates of hospitalization and early institutionalization for patients with dementia. The clinician should be able to promptly recognize NPI through the use of instruments capable of measuring their frequency and severity to support diagnosis, and to help monitor the treatment of behavioral symptoms. The aims of this review are to describe and update the construct 'MBI' and to revise the reported NPS related to prodromal stages of dementia (MCI and MBI) and dementia stages of Alzheimer's disease and frontotemporal lobar degeneration.

Developmental vulnerability of synapses and circuits associated with neuropsychiatric disorders

Psychiatric and neurodegenerative disorders, including intellectual disability, autism spectrum disorders (ASD), schizophrenia (SZ), and Alzheimer's disease, pose an immense burden to society. Symptoms of these disorders become manifest at different stages of life: early childhood, adolescence, and late adulthood, respectively. Progress has been made in recent years toward understanding the genetic substrates, cellular mechanisms, brain circuits, and endophenotypes of these disorders. Multiple lines of evidence implicate excitatory and inhibitory synaptic circuits in the cortex and hippocampus as key cellular substrates of pathogenesis in these disorders. Excitatory/inhibitory balance--modulated largely by dopamine--critically regulates cortical network function, neural network activity (i.e. gamma oscillations) and behaviors associated with psychiatric disorders. Understanding the molecular underpinnings of synaptic pathology and neuronal network activity may thus provide essential insight into the pathogenesis of these disorders and can reveal novel drug targets to treat them. Here, we discuss recent genetic, neuropathological, and molecular studies that implicate alterations in excitatory and inhibitory synaptic circuits in the pathogenesis of psychiatric disorders across the lifespan.

Effect of Alzheimer's disease risk genes on trajectories of cognitive function in the Cardiovascular Health Study

OBJECTIVE

The trajectory of cognitive decline in patients with late-onset Alzheimer's disease varies widely. Genetic variations in CLU, PICALM, and CR1 are associated with Alzheimer's disease, but it is unknown whether they exert their effects by altering cognitive trajectory in elderly individuals at risk for the disease.

METHOD

The authors developed a Bayesian model to fit cognitive trajectories in a cohort of elderly subjects and test for genetic effects. They first validated the model's ability to detect the previously established effects of APOE ε4 alleles on age at cognitive decline and of psychosis on the rate of cognitive decline in 802 subjects from the Cardiovascular Health Cognition Study who did not have dementia at study entry and developed incident dementia during follow-up. The authors then evaluated the effects of CLU, PICALM, and CR1 on age and rate of decline in 1,831 subjects who did not have dementia at study entry and then did or did not develop incident dementia by study's end.

RESULTS

The model generated robust fits to the observed cognitive trajectory data, and validation analysis supported the model's utility. CLU and CR1 were associated with more rapid cognitive decline. PICALM was associated with an earlier age at midpoint of cognitive decline. Associations remained after accounting for the effects of APOE and demographic factors.

CONCLUSIONS

Evaluation of cognitive trajectories provides a powerful approach to dissecting genetic effects on the processes leading to cognitive deterioration and Alzheimer's disease.

Origins of delusions in Alzheimer's disease

Research over the past two decades supports a shared aetiology for delusions in Alzheimer's disease (AD) and schizophrenia. Functional networks involved in salience attribution and belief evaluation have been implicated in the two conditions, and striatal D2/3 receptors are increased to a comparable extent. Executive/frontal deficits are common to both disorders and predict emergent symptoms. Putative risk genes for schizophrenia, which may modify the AD process, have been more strongly implicated in delusions than those directly linked with late-onset AD. Phenotypic correlates of delusions in AD may be dependent upon delusional subtype. Persecutory delusions occur early in the disease and are associated with neurochemical and neuropathological changes in frontostriatal circuits. In contrast, misidentification delusions are associated with greater global cognitive deficits and advanced limbic pathology. It is unclear whether the two subtypes are phenomenologically and biologically distinct or are part of a continuum, in which misidentification delusions manifest increasingly as the pathological process extends. This has treatment implications, particularly if they are found to have discrete chemical and/or pathological markers.