The 5-HTTPR polymorphism confers liability to a combined phenotype of psychotic and aggressive behavior in Alzheimer disease

Challenges and proposed solutions to conducting Alzheimer's disease psychosis trials

Alzheimer's disease psychosis (ADP) produces a significant burden for patients and their care partners, but at present there are no approved treatments for ADP. The lack of approved treatments may be due to the challenges of conducting clinical trials for this disease. This perspective article discusses distinct challenges and proposed solutions of conducting ADP trials involving seven key areas: (1) methods to reduce the variable and sometimes high rates of placebo response that occur for treatments of neuropsychiatric symptoms; (2) the use of combined or updated criteria that provide a precise, consensus definition of ADP; (3) the use of eligibility criteria to help recruit individuals representative of the larger ADP population and overcome the difficulty of recruiting patients with moderate-to-severe ADP; (4) consideration of multiple perspectives and implementation of technology to reduce the variability in the administration and scoring of neuropsychiatric symptom assessments; (5) the use of clinically appropriate, a priori-defined severity thresholds and responder cutoffs; (6) the use of statistical approaches that address absolute effect sizes and a three-tier approach to address the fluctuation of neuropsychiatric symptoms; and (7) the implementation of feasible diagnostic and target-engagement biomarkers as they become available. The goal of these proposed solutions is to improve the evaluation of potential ADP therapies, within the context of randomized, placebo-controlled trials with clinically meaningful endpoints and sustained treatment responses.

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.

Combination of Antidepressants and Antipsychotics as A Novel Treatment Option for Psychosis in Alzheimer's Disease

Background

Psychotic symptoms are reported as one of the most common complications of Alzheimer's disease (AD), affecting approximately half of AD patients, in whom they are associated with more rapid deterioration and increased mortality. Empiric treatments, namely first and second-generation antipsychotics, confer modest efficacy in AD patients with psychosis (AD+P) and themselves increase mortality. A recent genome-wide meta-analysis and early clinical trials suggest the use and beneficial effects of antidepressants among AD+P patients. This motivates our rationale for exploring their potential as a novel combination therapy option amongst these patients.

Methods

We included University of Pittsburgh Medical Center (UPMC) electronic medical records (EMRs) of 10,260 AD patients from January 2004 and October 2019 in our study. Survival analysis was performed to assess the effects of the combination of antipsychotics and antidepressants on the mortality of these patients. To provide more valuable insights on the hidden mechanisms of the combinatorial therapy, a protein-protein interaction (PPI) network representing AD+P was built, and network analysis methods were used to quantify the efficacy of these drugs on AD+P. An indicator score combining the measurements on the separation between drugs and the proximity between the drugs and AD+P was used to measure the effect of an antipsychotic-antidepressant drug pair against AD+P.

Results

Our survival analyses replicated that antipsychotic usage is strongly associated with increased mortality in AD patients while the co-administration of antidepressants with antipsychotics showed a significant beneficial effect in reducing mortality. Our network analysis showed that the targets of antipsychotics and antidepressants are well-separated, and antipsychotics and antidepressants have similar proximity scores to AD+P. Eight drug pairs, including some popular recommendations like Aripiprazole/Sertraline and other pairs not reported previously like Iloperidone/Maprotiline showed higher than average indicator scores which suggest their potential in treating AD+P via strong synergetic effects as seen in our study.

Conclusion

Our proposed combinations of antipsychotics and antidepressants therapy showed a strong superiority over current antipsychotics treatment for AD+P. The observed beneficial effects can be further strengthened by optimizing drug-pair selection based on our systems pharmacology analysis.

A New Hope in Alzheimer's Disease Psychosis: Pimavanserin

Alzheimer's disease (AD) ranks first among the causes of dementia worldwide. AD can develop a psychotic manifest at a significant rate. AD prognosis worsens by added psychosis clinic. There is no treatment approved by the United States Food and Drug Administration (FDA) among antipsychotics for Alzheimer's disease Psychosis (ADP). However, pimavanserine, an atypical antipsychotic, has been approved by the FDA for Parkinson's psychosis. It is predicted that pimavanserin, a new antipsychotic, will fill an important gap in this area. In clinical trials, it appears to be effective in the treatment of delusions and hallucinations at psychosis in both Parkinson's and AD. In this systematic review, we evaluated the analysis of current literature data on pimavanserin used in ADP. We searched the existing literature on clinical studies on pimavanserin therapy used in ADP. Data were determined by systematically searching PubMed, MEDLINE, EMBASE, and Google Scholar until December 2022. A total of 35 citations were found and uploaded on the Mendeley program. Abstracts and full texts of literature data were examined. Pimavanserin was observed, and satisfactory results were obtained in treating ADP. Pimavanserin has a unique mechanism of action. Pimavanserin, an atypical antipsychotic drug, has a low affinity for 5-HT2C receptors and has selective 5-HT2A reverse agonist/antagonist action. Pimavanserin has no clinically significant affinity for dopaminergic, histaminergic, muscarinic or adrenergic receptors. This agent may also achieve significant positive results in resistant psychosis treatments.

Psychosis in Alzheimer's Disease Is Associated With Increased Excitatory Neuron Vulnerability and Post-transcriptional Mechanisms Altering Synaptic Protein Levels

Alzheimer's disease with psychosis (AD+P) is a heritable phenotypic variant of the disease which is associated with more rapid cognitive deterioration compared to Alzheimer's disease without psychosis (AD–P). Cognitive decline in AD correlates with synapse loss, and our previous studies suggest that those with AD+P have a differentially affected synaptic proteome relative to those with AD–P. In this study, we utilized RNA-sequencing of dorsolateral prefrontal cortex (DLPFC) in a cohort of 80 AD cases to evaluate novel transcriptomic signatures that may confer risk of psychosis in AD. We found that AD+P was associated with a 9% reduction in excitatory neuron proportion compared to AD–P [Mean (SD) AD+P 0.295 (0.061); AD–P 0.324 (0.052), p = 0.026]. mRNA levels contributed only modestly to altered synaptic proteins in AD+P relative to AD–P. Instead, network analysis identified altered expression of gene modules from protein ubiquitination, unfolded protein response, eukaryotic initiation factor 2 (EIF2) signaling and endoplasmic reticulum stress pathways in AD+P. We previously found that neuropathologies account for ~18% of the variance in the occurrence of psychosis in AD. Further inclusion of cell type proportions and differentially expressed modules increased the percent of the variance in psychosis occurrence accounted for in our AD cohort to 67.5%.

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.

Agitation and Dementia: Prevention and Treatment Strategies in Acute and Chronic Conditions

Agitation is a behavioral syndrome characterized by increased, often undirected, motor activity, restlessness, aggressiveness, and emotional distress. According to several observations, agitation prevalence ranges from 30 to 50% in Alzheimer's disease, 30% in dementia with Lewy bodies, 40% in frontotemporal dementia, and 40% in vascular dementia (VaD). With an overall prevalence of about 30%, agitation is the third most common neuropsychiatric symptoms (NPS) in dementia, after apathy and depression, and it is even more frequent (80%) in residents of nursing homes. The pathophysiological mechanism underlying agitation is represented by a frontal lobe dysfunction, mostly involving the anterior cingulate cortex (ACC) and the orbitofrontal cortex (OFC), respectively, meaningful in selecting the salient stimuli and subsequent decision-making and behavioral reactions. Furthermore, increased sensitivity to noradrenergic signaling has been observed, possibly due to a frontal lobe up-regulation of adrenergic receptors, as a reaction to the depletion of noradrenergic neurons within the locus coeruleus (LC). Indeed, LC neurons mainly project toward the OFC and ACC. These observations may explain the abnormal reactivity to weak stimuli and the global arousal found in many patients who have dementia. Furthermore, agitation can be precipitated by several factors, e.g., the sunset or low lighted environments as in the sundown syndrome, hospitalization, the admission to nursing residencies, or changes in pharmacological regimens. In recent days, the global pandemic has increased agitation incidence among dementia patients and generated higher distress levels in patients and caregivers. Hence, given the increasing presence of this condition and its related burden on society and the health system, the present point of view aims at providing an extensive guide to facilitate the identification, prevention, and management of acute and chronic agitation in dementia patients.

Pimavanserin for the treatment of psychosis in Alzheimer’s disease: A literature review

BACKGROUND

Alzheimer’s disease (AD) is among the most prevalent forms of dementia in the world and neuropathological studies suggest similar high prevalence of mixed (AD + vascular) dementias. Approximately 25%-50% of individuals with AD develop psychosis sometime during their illness. The presence of psychosis in AD worsens outcomes. Currently there are no United States Food and Drug Administration (FDA) approved medications for the treatment of psychosis in AD. Pimavanserin, a novel atypical antipsychotic medication, was approved by the FDA for the treatment of hallucinations and delusions associated with Parkinson disease psychosis and is currently in clinical trials for the treatment of psychosis in AD.

AIM

To evaluate the existing literature regarding the use of pimavanserin for treating psychosis among individuals with AD.

METHODS

A literature review of clinical studies of pimavanserin treatment for psychosis in individuals with AD was performed using the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Trials were identified by systematically searching PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus through October 2019. The 5-point Jadad scoring system was used to assess the methodologic quality of the randomized placebo-controlled trials.

RESULTS

A total of 499 citations were retrieved and pooled in EndNote and de-duplicated to 258 citations. This set was uploaded to Covidence for screening. Two separate screeners (Srinivasan S and Tampi RR) evaluated the titles, abstracts, and full text of eligible articles. Of the identified 258 abstracts, 98 articles underwent full text review and 2 publications from 1 randomized controlled trial (RCT) were included in the final analysis. The quality of evidence was assessed to be of good methodologic quality, scoring 4 out of 5 using the 5-point Jadad questionnaire with the Jadad Scoring calculation. This systematic review found only one RCT that evaluated the use of pimavanserin for the treatment of psychosis among individuals with AD. This phase 2 trial resulted in two publications, the second of which was a subgroup analysis from the original study. The evidence from these two publications showed that pimavanserin improves psychotic symptoms among individuals with AD when compared to placebo at week 6.

CONCLUSION

Pimavanserin may be a pharmacologic consideration for the treatment for psychosis in AD. Additional RCTs are needed to assess the evidence of effectiveness before pimavanserin is considered a standard treatment.

Network Systems Pharmacology-Based Mechanism Study on the Beneficial Effects of Vitamin D against Psychosis in Alzheimer's Disease

Alzheimer's disease (AD) is a chronic neurodegenerative disease with significant financial costs and negative impacts on quality of life. Psychotic symptoms, i.e., the presence of delusions and/or hallucinations, is a frequent complication of AD. About 50% of AD patients will develop psychotic symptoms (AD with Psychosis, or AD + P) and these patients will experience an even more rapid cognitive decline than AD patients without psychosis (AD-P). In a previous analysis on medication records of 776 AD patients, we had shown that use of Vitamin D was associated with delayed time to psychosis in AD patients and Vitamin D was used more by AD-P than AD + P patients. To explore the potential molecular mechanism behind our findings, we applied systems pharmacology approaches to investigate the crosstalk between AD and psychosis. Specifically, we built protein-protein interaction (PPI) networks with proteins encoded by AD- and psychosis-related genes and Vitamin D-perturbed genes. Using network analysis we identified several high-impact genes, including NOTCH4, COMT, CACNA1C and DRD3 which are related to calcium homeostasis. The new findings highlight the key role of calcium-related signaling pathways in AD + P development and may provide a new direction and facilitate hypothesis generation for future drug development.

Management of Dementia-Related Psychosis, Agitation and Aggression: A Review of the Pharmacology and Clinical Effects of Potential Drug Candidates

Along with cognitive decline, 90% of patients with dementia experience behavioral and psychological symptoms of dementia, such as psychosis, aggression, agitation, and depression. Atypical antipsychotics are commonly prescribed off-label to manage certain symptoms, despite warnings from the regulatory agencies regarding the increased risk of mortality associated with their use in elderly patients. Moreover, these compounds display a limited clinical efficacy, mostly owing to the fact that they were developed to treat schizophrenia, a disease characterized by neurobiological deficits. Thus, to improve clinical efficacy, it has been suggested that patients with dementia should be treated with exclusively designed and developed drugs that interact with pharmacologically relevant targets. Within this context, numerous studies have suggested druggable targets that might achieve therapeutically acceptable pharmacological profiles. Based on this, several different drug candidates have been proposed that are being investigated in clinical trials for behavioral and psychological symptoms of dementia. We highlight the recent advances toward the development of therapeutic agents for dementia-related psychosis and agitation/aggression and discuss the relationship between the relevant biological targets and their etiology. In addition, we review the compounds that are in the early stage of development (discovery or preclinical phase) and those that are currently being investigated in clinical trials for dementia-related psychosis and agitation/aggression. We also discuss the mechanism of action of these compounds and their pharmacological utility in patients with dementia.

Escitalopram for agitation in Alzheimer's disease (S-CitAD): Methods and design of an investigator-initiated, randomized, controlled, multicenter clinical trial

INTRODUCTION

Alzheimer's disease (AD) is a disabling, common cause of dementia, and agitation is one of the most common and distressing symptoms for patients with AD. Escitalopram for agitation in Alzheimer's disease (S-CitAD) tests a novel, clinically derived therapeutic approach to treat agitation in patients with AD.

METHODS

S-CitAD is a NIH-funded, investigator-initiated, randomized, multicenter clinical trial. Participants receive a structured psychosocial intervention (PSI) as standard of care. Participants without sufficient response to PSI are randomized to receive 15 mg escitalopram/day or a matching placebo in addition to PSI. Primary outcome is the Modified Alzheimer's Disease Cooperative Study - Clinical Global Impression of Change (mADCS-CGIC).

DISCUSSION

S-CitAD will provide information about a practical, immediately available approach to treating agitation in patients with AD. S-CitAD may become a model of how to evaluate and predict treatment response in patients with AD and agitation as a neuropsychiatric symptom (ClinicalTrials.gov Identifier: NCT03108846).

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.

Hydroxytryptamine transporter gene-linked polymorphic region (5HTTLPR) is associated with delusions in Alzheimer's disease

Background

Serotoninergic pathways underlying delusion symptoms in Alzheimer's disease (AD) have not been fully clarified. 5-Hydroxytryptamine transporter gene-linked polymorphic region (5-HTTLPR) is a variable number tandem repeats in the promoter region of serotonin transporter encoding-gene affecting transcription.

Methods

We investigated the association of 5-HTTLPR with delusions in a total of 257 consecutive patients clinically diagnosed as AD according to the National Institute on Aging-Alzheimer's Association criteria. All participants underwent a comprehensive evaluation with a standardized comprehensive geriatric assessment and Neuropsychiatric Inventory.

Results

Delusion symptoms were observed in 171 patients (66.54%). In respect to AD patients without delusions, AD patients with delusions showed a low prevalence of S-plus carriers (5-HTTLPR-L/S + 5-HTTLPR-S/S genotypes) [p < 0.001; odds ratio (OR) = 0.240, 95% confidence interval (CI) = 0.121-0.471]. Logistic regression analysis adjusted for the apolipoprotein E polymorphism showed that in AD patients with delusions the presence of an 5-HTTLPR-S allele may reduce disease duration (p = 0.005; OR = 0.680, 95% CI = 0.522-0.886) and increase aberrant motor activity (p = 0.013; OR = 2.257, 95% CI = 1.195-4.260). The present findings suggested that 5-HTTLPR might be associated with delusions in AD. S-plus carriers might be associated with protective effect against delusions in AD.

Conclusions

More studies on wider samples of high selected demented patients are needed to confirm our results. However, the present findings suggested that a genetic factor related to serotonin metabolism might exert a protective role on the clinical expression of neuropsychiatric clusters in AD with important implications regarding mechanisms underlying delusions and their possible treatment across the AD and dementia spectrum.

The neurochemistry of agitation in Alzheimer's disease: a systematic review

OBJECTIVE

To provide an up-to-date systematic review of the characteristics, methodology and findings of studies that have investigated the neurochemistry of agitation in Alzheimer's disease (AD).

METHODS

Electronic databases were searched for published peer-reviewed articles which provided data on any neurotransmitter system in relation to agitation in AD. Screening of titles and abstracts and data extraction from full texts were conducted in duplicate.

RESULTS

Forty-five studies were included. Monoamines (serotonin, dopamine and noradrenaline) were most commonly investigated. A variety of methods were used to investigate the neurochemistry underlying agitation in AD and, although there were several conflicting findings, there was evidence of serotonergic deficit, relatively preserved dopaminergic function and compensatory overactivity of postsynaptic noradrenergic neurons in agitation in AD.

CONCLUSIONS

Disruption of the dynamic balance between multiple neurotransmitter systems could impair functional neural networks involved in affective regulation and executive function. Differences in study design and methodology may have contributed to conflicting findings. Future studies that overcome these limitations (e.g. using standardized criteria to define agitation) and employ neuroimaging methods such as MRI/PET to investigate specific neural networks are needed to clarify the role of neurotransmitter alterations in these patients.

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.

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.

Genetics of psychosis of Alzheimer disease

Psychotic symptoms, comprised of delusions and hallucinations, occur in about half of individuals with Alzheimer disease (AD with psychosis, AD+P). These individuals have greater agitation, aggression, depression, functional impairment, and mortality than individuals without psychosis (AD-P). Although the exact etiopathogenesis of AD+P is unclear, the rapidly developing field of genomics continues to expand our understanding of this disease. Several independent studies have demonstrated familial aggregation and heritability of AD+P. Linkage studies have been suggestive of loci on several chromosomes associated with AD+P. Association studies examining apolipoprotein E gene, the best established genetic risk factor for late-onset AD, did not find any significant association of this gene with AD+P. Other candidate gene studies focusing on monoamine neurotransmitter systems have yielded equivocal results. A genome-wide association study and studies examining copy number variations recently have detected suggestive associations, but have been underpowered. Approaches to increase sizes of AD+P samples for genome wide association studies are discussed. © 2016 Wiley Periodicals, Inc.

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.

Biomarkers of aggression in dementia

Dementia is a clinical syndrome defined by progressive global impairment of acquired cognitive abilities. It can be caused by a number of underlying conditions. The most common types of dementia are Alzheimer's disease (AD), frontotemporal dementia (FTD), vascular cognitive impairment (VCI) and dementia with Lewy bodies (DLB). Despite the fact that cognitive impairment is central to the dementia, noncognitive symptoms, most commonly described nowadays as neuropsychiatric symptoms (NPS) exist almost always at certain point of the illness. Aggression as one of the NPS represents danger both for patients and caregivers and the rate of aggression correlates with the loss of independence, cognitive decline and poor outcome. Therefore, biomarkers of aggression in dementia patients would be of a great importance. Studies have shown that different genetic factors, including monoamine signaling and processing, can be associated with various NPS including aggression. There have been significant and multiple neurotransmitter changes identified in the brains of patients with dementia and some of these changes have been involved in the etiology of NPS. Aggression specific changes have also been observed in neuropathological studies. The current consensus is that the best approach for development of such biomarkers may be incorporation of genetics (polymorphisms), neurobiology (neurotransmitters and neuropathology) and neuroimaging techniques.

Agitation and aggression in Alzheimer's disease: an update on pharmacological and psychosocial approaches to care

Agitation and aggression are prevalent in Alzheimer's disease and have significant consequences for the patient, caregiver and care system more generally. We briefly discuss the epidemiology and etiology of agitation and aggression in Alzheimer's disease and provide an overview of assessment and approaches to care. We then review the evidence for and against a number of pharmacological and psychosocial approaches to care. There has been a growth in the evidence base for psychosocial interventions and nonpharmacological approaches to care should ordinarily be the first option. Antipsychotics remain the pharmacological agents with most evidence to support their use while there is more limited evidence for other agents such as carbamazepine and selective serotonin reuptake inhibitors such as citalopram.

Antiepileptic drugs for the treatment of agitation and aggression in dementia: do they have a place in therapy?

Antiepileptic drugs (AEDs) are a class of medications that have received considerable attention as possible treatments for agitation and aggression in patients with dementia. This attention has been driven in equal measure by promising findings from limited trial and observational data and the desire to find treatments with improved tolerability. Their use, to date, has been largely confined to circumstances where first-line treatments have proven inadequate or are poorly tolerated. In recent years there has been some growth in the evidence base, and we can now make more informed recommendations regarding a number of older AEDs. Carbamazepine continues to have the best evidence to support its use, although the evidence base remains relatively small and concerns regarding tolerability limit its use. There is now more consistent evidence that valproate preparations should not be used for agitation and aggression in dementia. Despite a lack of high-quality data, some results have been reported for several newer medications, including levetiracetam, oxcarbazepine, gabapentin, topiramate and lamotrigine, and a number of these warrant further investigation. Recent findings and implications for clinical practice are discussed.

Behavioral and psychological symptoms in Alzheimer's disease

Neuropsychiatric symptoms (NPS) such as depression, apathy, aggression, and psychosis are now recognized as core features of Alzheimer's disease (AD), and there is a general consensus that greater symptom severity is predictive of faster cognitive decline, loss of independence, and even shorter survival. Whether these symptoms result from the same pathogenic processes responsible for cognitive decline or have unique etiologies independent of AD-associated neurodegeneration is unclear. Many structural and metabolic features of the AD brain are associated with individual neuropsychiatric symptoms or symptom clusters. In addition, many genes have been identified and confirmed that are associated with symptom risk in a few cases. However, there are no single genes strongly predictive of individual neuropsychiatric syndromes, while functional and structural brain changes unique to specific symptoms may reflect variability in progression of the same pathological processes. Unfortunately, treatment success for these psychiatric symptoms may be lower when comorbid with AD, underscoring the importance of future research on their pathobiology and treatment. This review summarizes some of the most salient aspects of NPS pathogenesis.

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.

Determining the association of the 5HTTLPR polymorphism with delusions and hallucinations in Lewy body dementias

OBJECTIVES

To determine whether the 5HTTLPR serotonin transporter polymorphism is associated with delusions and hallucinations in people with dementia with Lewy bodies (DLB) and Parkinson disease dementia (PDD).

DESIGN

Prospective cohort study.

PARTICIPANTS

A total of 187 individuals, recruited from centres in Norway, Sweden, and the United Kingdom were included in this study; 97 with clinically or neuropathologically diagnosed DLB/PDD and 90 cognitively normal individuals as a comparison group.

MEASUREMENTS

All participants with dementia underwent serial evaluation of neuropsychiatric symptoms to assess the presence of persistent delusions and hallucinations using the Columbia University Scale for Psychopathology in Alzheimer disease, the Neuropsychiatric Inventory, or the Present Behavioural Examination. Severity of cognitive impairment was measured using the Mini Mental State Examination (MMSE). Individuals were genotyped for the 5HTTLPR polymorphism.

RESULTS

Logistic regression demonstrated that homozygosity for the L/L genotype and lower MMSE were associated with an increased risk for delusions (odds ratio: 11.5 and 1.16, respectively). Neither was significantly associated with hallucinations.

CONCLUSIONS

This study is the first to demonstrate the 5HTTLPR polymorphism is associated with delusions in Lewy body dementias, with important implications regarding the mechanisms underlying this symptom across the AD/DLB/PDD spectrum. Further studies are warranted to investigate this relationship further and examine treatment opportunities.

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.

Genetics of Psychosis in Alzheimer Disease

Psychosis occurs in approximately half of patients with Alzheimer disease (AD with psychosis, AD+P). AD+P patients have more rapid cognitive decline, greater behavioral symptoms, and higher mortality than do AD patients without psychosis. Studies in three independent cohorts have shown that psychosis in AD aggregates in families, with estimated heritability of 29.5 - 60.8%. These findings have motivated studies to investigate and uncover the genes responsible for the development of psychosis, with the ultimate goal of identifying potential biologic mechanisms that may serve as leads to specific therapies. Linkage analyses have implicated loci on chromosomes 2, 6, 7, 8, 15, and 21 with AD+P. Association studies of APOE do not support it as a risk gene for psychosis in AD. No other candidate genes, such as neurodegenerative and monoamine genes, show conclusive evidence of association with AD+P. However, a recent genome-side association study has produced some promising leads, including among them genes that have been associated with schizophrenia. This review summarizes the current knowledge of the genetic basis of AD+P.

Behavioral genetics and criminal responsibility at the courtroom

Several questions arise from the recent use of behavioral genetic research data in the courtroom. Ethical issues concerning the influence of biological factors on human free will, must be considered when specific gene patterns are advocated to constrain court's judgment, especially regarding violent crimes. Aggression genetics studies are both difficult to interpret and inconsistent, hence, in the absence of a psychiatric diagnosis, genetic data are currently difficult to prioritize in the courtroom. The judge's probabilistic considerations in formulating a sentence must take into account causality, and the latter cannot be currently ensured by genetic data.

Cognitive impairment in studies of 5HTTLPR and psychosis in Alzheimer's disease: a systematic review

BACKGROUND/AIMS

Cognitive impairment is a well-established correlate of psychotic symptoms in Alzheimer's disease (AD-P). We review whether this relationship has confounded previous genetic association studies of 5HTTLPR and AD-P.

METHODS

We reviewed all studies on 5HTTLPR and conducted a semi-quantitative analysis.

RESULTS

Three out of 4 studies with low MMSE reported a significant association, while 1 out of 4 with high MMSE reported a significant association.

CONCLUSIONS

Variation in cognitive impairment in past studies has contributed to the inconsistency in findings. The findings presented here bring a greater clarity to our understanding of the role of 5HTTLPR in AD-P.

Neuropsychiatric symptoms in Alzheimer's disease: past progress and anticipation of the future

Neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) are widespread and disabling. This has been known since Dr. Alois Alzheimer's first case, Frau Auguste D., presented with emotional distress and delusions of infidelity/excessive jealousy, followed by cognitive symptoms. Being cognizant of this, in 2010 the Alzheimer's Association convened a research roundtable on the topic of NPS in AD. A major outcome of the roundtable was the founding of a Professional Interest Area (PIA) within the International Society to Advance Alzheimer's Research and Treatment (ISTAART). The NPS-PIA has prepared a series of documents that are intended to summarize the literature and provide more detailed specific recommendations for NPS research. This overview paper is the first of these living documents that will be updated periodically as the science advances. The overview is followed by syndrome-specific synthetic reviews and recommendations prepared by NPS-PIA workgroups on depression, apathy, sleep, agitation, and psychosis.

Sociodemographic characteristics, clinical factors, and genetic polymorphisms associated with Alzheimer's disease

OBJECTIVE

Alzheimer's disease (AD) has a multifactorial etiology involving an interaction of genetic and environmental factors. The Apolipoprotein E ε4 (ApoE ε4) is the single most important genetic risk factor for sporadic AD. Our aim was to study the association between sociodemographic, clinical data and gene polymorphisms in patients with sporadic AD in a heterogeneous genomic Brazilian population with low educational levels.

METHODS

We selected 169 sporadic AD patients and 97 controls older than 65 years and compared co-variables between them: age, years of education, vascular risk factors, genomic ancestry, and functional polymorphisms of ApoE, BDNF, COMT, and 5-HTTLPR. We also determined the genomic ancestry of all individuals.

RESULTS

The average years of education was significantly smaller in the patient's group (p = 0.003), and they had a history of depression when compared with controls (p < 0.001). The carriers of ApoE ε4 have an earlier onset of the disease (76.9 years) (p = 0.001) than ApoE ε3 (79.5 years) (p = 0.024). Patients with Met allele of Val66Met have a tendency to later onset of disease (p = 0.056). There were no differences in the genomic ancestry between groups.

CONCLUSION

Low level of education and history of depression were associated with AD. Public policies and intensive observation of old-age patients with lifetime history of depression, especially APOE ε4 carriers, could improve the well-being of our population.

Mibampator (LY451395) randomized clinical trial for agitation/aggression in Alzheimer's disease

BACKGROUND

Mibampator, an amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor potentiator, was evaluated for treatment of agitation and aggression (A/A) in Alzheimer's disease (AD).

METHODS

Outpatients (n = 132) with probable AD and A/A randomized to 12 weeks of double-blind treatment with 3-mg po mibampator or placebo were assessed using the 4-domain A/A subscale of the Neuropsychiatric Inventory (NPI-4-A/A) derived from the Neuropsychiatric Inventory. Secondary measures included the Cohen-Mansfield Agitation Inventory, Cornell Scale for Depression in Dementia, Frontal Systems Behavior Inventory (FrSBe), and Alzheimer's Disease Assessment Scale-Cognitive. Efficacy was analyzed using mixed-effects model repeated measures from baseline to endpoint. Adverse events (AEs), labs, vital signs, and electrocardiograms were monitored.

RESULTS

Baseline characteristics were comparable between groups. Both groups improved on the NPI-4-A/A, but without group differences. Among secondaries, mibampator was significantly better (p = 0.007) than placebo only on the FrSBe. AEs were similar between groups. One death occurred in the placebo group.

CONCLUSION

Possible explanations for no significant group differences include caregiver, drug target engagement, and design issues. This trial is registered on ClinicalTrials.gov; ID: NCT00843518.

The role of the serotonergic system at the interface of aggression and suicide

Alterations in serotonin (5-HT) neurochemistry have been implicated in the aetiology of all major neuropsychiatric disorders, ranging from schizophrenia to mood and anxiety-spectrum disorders. This review will focus on the multifaceted implications of 5-HT-ergic dysfunctions in the pathophysiology of aggressive and suicidal behaviours. After a brief overview of the anatomical distribution of the 5-HT-ergic system in the key brain areas that govern aggression and suicidal behaviours, the implication of 5-HT markers (5-HT receptors, transporter as well as synthetic and metabolic enzymes) in these conditions is discussed. In this regard, particular emphasis is placed on the integration of pharmacological and genetic evidence from animal studies with the findings of human experimental and genetic association studies. Traditional views postulated an inverse relationship between 5-HT and aggression and suicidal behaviours; however, ample evidence has shown that this perspective may be overly simplistic, and that such pathological manifestations may reflect alterations in 5-HT homoeostasis due to the interaction of genetic, environmental and gender-related factors, particularly during early critical developmental stages. The development of animal models that may capture the complexity of such interactions promises to afford a powerful tool to elucidate the pathophysiology of impulsive aggression and suicidability, and identify new effective therapies for these conditions.

Genetics of aggression

Aggression mediates competition for food, mating partners, and habitats and, among social animals, establishes stable dominance hierarchies. In humans, abnormal aggression is a hallmark of neuropsychiatric disorders and can be elicited by environmental factors acting on an underlying genetic susceptibility. Identifying the genetic architecture that predisposes to aggressive behavior in people is challenging because of difficulties in quantifying the phenotype, genetic heterogeneity, and uncontrolled environmental conditions. Studies on mice have identified single-gene mutations that result in hyperaggression, contingent on genetic background. These studies can be complemented by systems genetics approaches in Drosophila melanogaster, in which mutational analyses together with genome-wide transcript analyses, artificial selection studies, and genome-wide analysis of epistasis have revealed that a large segment of the genome contributes to the manifestation of aggressive behavior with widespread epistatic interactions. Comparative genomic analyses based on the principle of evolutionary conservation are needed to enable a complete dissection of the neurogenetic underpinnings of this universal fitness trait.

Behavioral genetics of neurodegenerative disorders

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, and is typically characterized by memory loss. In addition, during the disease progression, most patients develop behavioural and psychiatric symptoms of dementia (BPSD). Frontotemporal Lobar Degeneration (FTLD) is the most frequent neurodegenerative disorder with a presenile onset. It is characterized mainly by behavioural disturbances, whereas memory is conserved. The two major neuropathologic hallmarks of AD are extracellular Amyloid beta (Ab) plaques and intracellular neurofibrillary tangles (NFTs). Conversely, in FTLD the deposition of tau has been observed in a number of cases, but in several brains there is no deposition of tau but instead a positivity for ubiquitin. In some families these diseases are inherited in an autosomal dominant fashion. Genes responsible for familial AD include the Amyloid Precursor Protein (b-APP), Presenilin 1 (PS1)and Presenilin 2 (PS2). The majority of mutations in these genes are often associated with a very early onset (40–50 years of age). Regarding FTLD, the first mutations described are located in the Microtubule Associated Protein Tau gene(MAPT). Tau is a component of microtubules, which represent the internal support structures for the transport of nutrients, vesicles, mitochondria and chromosomes within the cell. Mutations in MAPT are associated with an early onset of the disease (40–50 years), and the clinical phenotype is consistent with Frontotemporal Dementia (FTD). Recently, mutations in a second gene, named progranulin(GRN), have been identified in some families with FTLD. The pathology associated with these mutations is most frequently characterized by the immunostaining of TAR DNA Binding Protein 43 (TDP-43), which is a transcription factor. The clinical phenotype associated with GRN mutations is highly heterogeneous,including FTD, Progressive Aphasia, Corticobasal Syndrome, and AD. Age at disease onset is variable, ranging from 45 to 85 years of age. The majority of cases of AD and FTLD are however sporadic, and likely several genetic and environmental factors contribute to their development. Concerning AD, it is known that the presence of the e4 allele of the Apolipoprotein E gene is a susceptibility factor,increasing the risk of about 4 fold. A number of additional genetic factors,including cytokines, chemokines, Nitric Oxide Synthases, contribute to the susceptibility for the disease. Some of them also influence the risk to develop FTLD.Variability in serotonin transporter gene could influence the development of BPSD. In this chapter, current knowledge on molecular mechanisms at the basis of AD and FTLD, as well as the role of genetics, will be presented and discussed.

Escitalopram versus risperidone for the treatment of behavioral and psychotic symptoms associated with Alzheimer's disease: a randomized double-blind pilot study

BACKGROUND

Antipsychotics are frequently used to treat psychosis, aggression and agitation in patients with Alzheimer's disease (AD), but safety warnings abound. Escitalopram was investigated since citalopram has demonstrated some effectiveness in AD. We compared escitalopram and risperidone for psychotic symptoms and agitation associated with AD.

METHODS

Inpatients with AD, who had been hospitalized because of behavioral symptoms, were recruited to a six-week randomized, double-blind, controlled trial. Participants (n = 40) were randomized to once daily risperidone 1 mg or escitalopram 10 mg.

RESULTS

The NPI total score improved in both groups. Onset was earlier in the risperidone-treated group, but improvement did not significantly differ between groups by study end. Completion rates differed for escitalopram (75%) and risperidone (55%), mainly due to adverse events. There were no adverse events in the escitalopram group, while in the risperidone group two patients suffered severe extrapyramidal symptoms and four patients suffered acute physical illness necessitating transfer to general hospital.

CONCLUSION

Escitalopram and risperidone did not differ in efficacy in reducing psychotic symptoms and agitation in patients with AD. Completion rates were higher for escitalopram-treated patients. Replication in larger trials with ambulatory patients is needed.

Genetic determinants of aggression and impulsivity in humans

Human aggression/impulsivity-related traits have a complex background that is greatly influenced by genetic and non-genetic factors. The relationship between aggression and anxiety is regulated by highly conserved brain regions including amygdala, which controls neural circuits triggering defensive, aggressive, or avoidant behavioral models. The dysfunction of neural circuits responsible for emotional control was shown to represent an etiological factor of violent behavior. In addition to the amygdala, these circuits also involve the anterior cingulated cortex and regions of the prefrontal cortex. Excessive reactivity in the amygdala coupled with inadequate prefrontal regulation serves to increase the likelihood of aggressive behavior. Developmental alterations in prefrontal-subcortical circuitry as well as neuromodulatory and hormonal abnormality appear to play a role. Imbalance in testosterone/serotonin and testosterone/cortisol ratios (e.g., increased testosterone levels and reduced cortisol levels) increases the propensity toward aggression because of reduced activation of the neural circuitry of impulse control and self-regulation. Serotonin facilitates prefrontal inhibition, and thus insufficient serotonergic activity can enhance aggression. Genetic predisposition to aggression appears to be deeply affected by the polymorphic genetic variants of the serotoninergic system that influences serotonin levels in the central and peripheral nervous system, biological effects of this hormone, and rate of serotonin production, synaptic release and degradation. Among these variants, functional polymorphisms in the monoamine oxidase A (MAOA) and serotonin transporter (5-HTT) may be of particular importance due to the relationship between these polymorphic variants and anatomical changes in the limbic system of aggressive people. Furthermore, functional variants of MAOA and 5-HTT are capable of mediating the influence of environmental factors on aggression-related traits. In this review, we consider genetic determinants of human aggression, with special emphasis on genes involved in serotonin and dopamine metabolism and function.

Behavioural genetics of Alzheimer's disease: a comprehensive review

Behavioural and psychological symptoms of dementia (BPSD) are present in the course of the illness in up to 90% of patients with Alzheimer's disease (AD). They are the main source of caregiver burden and one of the major factors contributing to early institutionalization. The involvement of a genetic component in BPSD aetiology seems beyond controversy, though the exact significance of particular polymorphisms is uncertain in the majority of cases. Multiple genes have been assessed for their putative influence on BPSD risk. In this paper we review the behavioural genetics of AD, particularly the importance, with respect to BPSD risk, of genes coding for apolipoprotein E and proteins involved in the process of neurotransmission: serotonin receptors, serotonin transporter, COMT, MAO-A, tryptophan hydroxylase and dopamine receptors. A general conclusion is the striking inconsistency of the findings, unsurprising in the field of psychiatric genetics. The potential reasons for such discrepancy are exhaustively discussed.

Genetics of psychosis in Alzheimer's disease: a review

In and of itself, late-onset Alzheimer's disease (AD) can be a devastating illness. However, a sub-group of AD patients develop psychosis as the disease progresses. These patients have an added burden of greater cognitive impairment, higher rates of institutionalization, and higher mortality than AD patients without psychosis. While the etiopathogenesis such as psychosis in AD (AD+P) is not known, mounting evidence accrued over the past ten years indicates that AD+P represents a distinct phenotype with a genetic basis. Elucidating the genetic mechanism of AD+P is crucial if better pharmaceutical treatments are to be developed for these patients. The goal of this review is to summarize what is currently known regarding the genetic basis of psychosis in AD. Specific attention is given to familial aggregation and heritability, linkage to chromosomal loci, and associations of candidate genes of APOE and the monoamine neurotransmitter system.

Serotonin transporter triallelic genotype and response to citalopram and risperidone in dementia with behavioral symptoms

The risk/benefit ratio of pharmacotherapy for behavioral symptoms of dementia is questionable: second-generation antipsychotics are poorly tolerated, and the efficacy of alternative treatments, for example, selective serotonin-reuptake inhibitors (SSRIs), is uncertain. Biomarkers of treatment response may improve this risk/benefit ratio. The length polymorphism of the serotonin transporter promoter gene (5-HTTLPR/SLC6A4) may moderate tolerability of SSRIs and expression of behavioral symptoms in dementia. We assessed the effect of 5-HTTLPR on tolerability and efficacy of citalopram and risperidone in a 12-week randomized controlled trial, which included nondepressed patients with dementia hospitalized for behavioral or psychotic symptoms. Genotypes including the A/G polymorphism of the L allele (rs25531) were determined in 92 of 103 participants. We used pattern-mixture models to account for dropout. Low-expression alleles (S and Lg) predicted greater early and overall side effects of citalopram and early treatment discontinuation. These results remained unchanged after excluding African-American participants and in covariate analyses. Unexpectedly, low-expression alleles seemed to predict greater early side effects of risperidone (but not early discontinuation) and poorer early response of psychosis symptoms to risperidone. In conclusion, 5-HTTLPR may be a useful biomarker of SSRI intolerance in dementia. Our findings of intolerance of a second-generation antipsychotics and persistence of psychosis in patients with low-expression alleles needs to be replicated.

Serotonergic system genes in psychosis of Alzheimer dementia: meta-analysis

OBJECTIVE

The authors attempted to understand the role of two serotonin system genes, HTR2A and SLC6A4, on psychosis associated with Alzheimer dementia (AD).

METHOD

Relevant published studies were assessed, and their data were meta-analyzed to determine pooled odds ratios (ORs) that were assessed for heterogeneity. Additional robustness checks were performed to assess for publication bias and any undue influence from a single study. Finally, the number of studies required to invalidate positive findings was determined.

RESULTS

The C allele of HTR2A emerged as a significant risk factor for psychosis, with an allelic OR of 2.191 that increased to 5.143 for the homozygous CC genotype. The SLC6A4 polymorphism was not reliably associated with either psychosis or delusions.

CONCLUSIONS

The strong and robust positive association that was noted between the C allele of HTR2A and psychosis suggests that the HTR2A T102C polymorphism is a significant risk factor for psychosis of AD.

Management of agitation and aggression associated with Alzheimer disease

Agitation and aggression are frequently occurring and distressing behavioral and psychological symptoms of dementia (BPSD). These symptoms are disturbing for individuals with Alzheimer disease, commonly confer risk to the patient and others, and present a major management challenge for clinicians. The most widely prescribed pharmacological treatments for these symptoms-atypical antipsychotics-have a modest but significant beneficial effect in the short-term treatment (over 6-12 weeks) of aggression but limited benefits in longer term therapy. Benefits are less well established for other symptoms of agitation. In addition, concerns are growing over the potential for serious adverse outcomes with these treatments, including stroke and death. A detailed consideration of other pharmacological and nonpharmacological approaches to agitation and aggression in patients with Alzheimer disease is, therefore, imperative. This article reviews the increasing evidence in support of psychological interventions or alternative therapies (such as aromatherapy) as a first-line management strategy for agitation, as well as the potential pharmacological alternatives to atypical antipsychotics-preliminary evidence for memantine, carbamazepine, and citalopram is encouraging.

Psychotic and behavioural symptoms in a population-based sample of the very elderly subjects

OBJECTIVE

The aim was to elucidate the relationship between psychotic and behavioural symptoms in the elderly.

METHOD

A representative sample of 85 year old subjects living in Gothenburg, Sweden (n = 451) was assessed with neuropsychiatric examinations, key informant interviews and record reviews.

RESULTS

Fourteen percent of these very elderly subjects had paranoid symptoms with concomitant anxious agitation and/or irritability/anger. Hallucinations and paranoid symptoms were both associated with a pattern of behavioural symptoms including both anxious agitation and irritability/anger simultaneously in both demented [hallucinations, Odds ratio (OR) 2.8, Confidence interval (CI) 1.2-6.7, paranoid symptoms OR 5.6 CI 2.2-14.2] and non-demented (hallucinations OR 3.2 CI 1.2-8.3, paranoid symptoms OR 4.8 CI 2.0-11.8).

CONCLUSION

Psychotic symptoms are associated with behavioural symptoms regardless of dementia status. Since these symptoms lead to decreased ability to function in daily life and increased caregiver burden, it is important for health professionals to identify and treat these symptoms also in non-demented.

A Multiple Indicators Multiple Causes (MIMIC) model of Behavioural and Psychological Symptoms in Dementia (BPSD)

INTRODUCTION

Although there is evidence for distinct behavioural sub-phenotypes in Alzheimer's disease (AD), their inter-relationships and the effect of clinical variables on their expression have been little investigated.

METHODS

We have analysed a sample of 1850 probable AD patients from the UK and Greece with 10 item Neuropsychiatric Inventory (NPI) data. We applied a Multiple Indicators Multiple Causes (MIMIC) approach to investigate the effect of MMSE, disease duration, gender, age and age of onset on the structure of a four-factor model consisting of "psychosis", "moods", "agitation" and "behavioural dyscontrol".

RESULTS

Specific clinical variables predicted the expression of individual factors. When the inter-relationship of factors is modelled, some previously significant associations are lost. For example, lower MMSE scores predict psychosis, agitation and behavioural dyscontrol factors, but psychosis and mood predict the agitation factor. Taking these associations into account MMSE scores did not predict agitation.

CONCLUSIONS

The complexity of the inter-relations between symptoms, factors and clinical variables is efficiently captured by this MIMIC model.