Neuropsychiatric symptoms in dementia—A role for neuroinflammation?

Neuropsychiatric symptoms in cognitive decline and Alzheimer's disease: biomarker discovery using plasma proteomics

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS) are common in older people with cognitive impairment and Alzheimer's disease (AD). No biomarkers to detect the related pathology or predict the clinical evolution of NPS are available yet. This study aimed to identify plasma proteins that may serve as biomarkers for NPS and NPS-related clinical disease progression.

METHODS

A panel of 190 plasma proteins was quantified using Luminex xMAP in the Alzheimer's Disease Neuroimaging Initiative cohort. NPS and cognitive performance were assessed at baseline and after 1 and 2 years. Logistic regression, receiver operating characteristic analysis and cross-validation were used to address the relations of interest.

RESULTS

A total of 507 participants with mild cognitive impairment (n=396) or mild AD dementia (n=111) were considered. Selected plasma proteins improved the prediction of NPS (area under the curve (AUC) from 0.61 to 0.76, p<0.001) and future NPS (AUC from 0.63 to 0.80, p<0.001) when added to a reference model. Distinct protein panels were identified for single symptoms. Among the selected proteins, ANGT, CCL1 and IL3 were associated with NPS at all three time points while CCL1, serum glutamic oxaloacetic transaminase and complement factor H were also associated with cognitive decline. The associations were independent of the presence of cerebral AD pathology as assessed using cerebrospinal fluid biomarkers.

CONCLUSIONS

Plasma proteins are associated with NPS and improve prediction of future NPS.

Associations Between Neuropsychiatric Symptoms and Inflammation in Neurodegenerative Dementia: A Systematic Review

Background

Neuropsychiatric symptoms are common in dementia and linked to adverse outcomes. Inflammation is increasingly recognized as playing a role as a driver of early disease progression in Alzheimer's disease (AD) and related dementias. Inflammation has also been linked to primary psychiatric disorders, however its association with neuropsychiatric symptoms in neurodegenerative dementias remains uncertain.

Methods

We conducted a systematic literature review investigating associations between inflammation and neuropsychiatric symptoms in neurodegenerative dementias, including AD, Lewy body, Frontotemporal, Parkinson's (PD) and Huntington's disease dementias.

Results

Ninety-nine studies met our inclusion criteria, and the majority (n = 59) investigated AD and/or mild cognitive impairment (MCI). Thirty-five studies included PD, and only 6 investigated non-AD dementias. Inflammation was measured in blood, CSF, by genotype, brain tissue and PET imaging. Overall, studies exhibited considerable heterogeneity and evidence for specific inflammatory markers was inconsistent, with lack of replication and few longitudinal studies with repeat biomarkers. Depression was the most frequently investigated symptom. In AD, some studies reported increases in peripheral IL-6, TNF-a associated with depressive symptoms. Preliminary investigations using PET measures of microglial activation found an association with agitation. In PD, studies reported positive associations between TNF-a, IL-6, CRP, MCP-1, IL-10 and depression.

Conclusion

Central and peripheral inflammation may play a role in neuropsychiatric symptoms in neurodegenerative dementias; however, the evidence is inconsistent. There is a need for multi-site longitudinal studies with detailed assessments of neuropsychiatric symptoms combined with replicable peripheral and central markers of inflammation.

Inflammatory biomarkers for neurobehavioral dysregulation in former American football players: findings from the DIAGNOSE CTE Research Project

BACKGROUND

Traumatic encephalopathy syndrome (TES) is defined as the clinical manifestation of the neuropathological entity chronic traumatic encephalopathy (CTE). A core feature of TES is neurobehavioral dysregulation (NBD), a neuropsychiatric syndrome in repetitive head impact (RHI)-exposed individuals, characterized by a poor regulation of emotions/behavior. To discover biological correlates for NBD, we investigated the association between biomarkers of inflammation (interleukin (IL)-1β, IL-6, IL-8, IL-10, C-reactive protein (CRP), tumor necrosis factor (TNF)-α) in cerebrospinal fluid (CSF) and NBD symptoms in former American football players and unexposed individuals.

METHODS

Our cohort consisted of former American football players, with (n = 104) or without (n = 76) NBD diagnosis, as well as asymptomatic unexposed individuals (n = 55) from the DIAGNOSE CTE Research Project. Specific measures for NBD were derived (i.e., explosivity, emotional dyscontrol, impulsivity, affective lability, and a total NBD score) from a factor analysis of multiple self-report neuropsychiatric measures. Analyses of covariance tested differences in biomarker concentrations between the three groups. Within former football players, multivariable linear regression models assessed relationships among log-transformed inflammatory biomarkers, proxies for RHI exposure (total years of football, cumulative head impact index), and NBD factor scores, adjusted for relevant confounding variables. Sensitivity analyses tested (1) differences in age subgroups (< 60, ≥ 60 years); (2) whether associations could be identified with plasma inflammatory biomarkers; (3) associations between neurodegeneration and NBD, using plasma neurofilament light (NfL) chain protein; and (4) associations between biomarkers and cognitive performance to explore broader clinical symptoms related to TES.

RESULTS

CSF IL-6 was higher in former American football players with NBD diagnosis compared to players without NBD. Furthermore, elevated levels of CSF IL-6 were significantly associated with higher emotional dyscontrol, affective lability, impulsivity, and total NBD scores. In older football players, plasma NfL was associated with higher emotional dyscontrol and impulsivity, but also with worse executive function and processing speed. Proxies for RHI exposure were not significantly associated with biomarker concentrations.

CONCLUSION

Specific NBD symptoms in former American football players may result from multiple factors, including neuroinflammation and neurodegeneration. Future studies need to unravel the exact link between NBD and RHI exposure, including the role of other pathophysiological pathways.

Converged avenues: depression and Alzheimer's disease- shared pathophysiology and novel therapeutics

Depression, a highly prevalent disorder affecting over 280 million people worldwide, is comorbid with many neurological disorders, particularly Alzheimer's disease (AD). Depression and AD share overlapping pathophysiology, and the search for accountable biological substrates made it an essential and intriguing field of research. The paper outlines the neurobiological pathways coinciding with depression and AD, including neurotrophin signalling, the hypothalamic-pituitary-adrenal axis (HPA), cellular apoptosis, neuroinflammation, and other aetiological factors. Understanding overlapping pathways is crucial in identifying common pathophysiological substrates that can be targeted for effective management of disease state. Antidepressants, particularly monoaminergic drugs (first-line therapy), are shown to have modest or no clinical benefits. Regardless of the ineffectiveness of conventional antidepressants, these drugs remain the mainstay for treating depressive symptoms in AD. To overcome the ineffectiveness of traditional pharmacological agents in treating comorbid conditions, a novel therapeutic class has been discussed in the paper. This includes neurotransmitter modulators, glutamatergic system modulators, mitochondrial modulators, antioxidant agents, HPA axis targeted therapy, inflammatory system targeted therapy, neurogenesis targeted therapy, repurposed anti-diabetic agents, and others. The primary clinical challenge is the development of therapeutic agents and the effective diagnosis of the comorbid condition for which no specific diagnosable scale is present. Hence, introducing Artificial Intelligence (AI) into the healthcare system is revolutionary. AI implemented with interdisciplinary strategies (neuroimaging, EEG, molecular biomarkers) bound to have accurate clinical interpretation of symptoms. Moreover, AI has the potential to forecast neurodegenerative and psychiatric illness much in advance before visible/observable clinical symptoms get precipitated.

Neuropsychiatric Symptoms are Related to Blood-biomarkers in Major Neurocognitive Disorders

BACKGROUND

Neuropsychiatric symptoms (NPS) are highly prevalent among individuals with major neurocognitive disorders (MNCD).

OBJECTIVE

Here, we characterized blood biomarkers (metabolic, inflammatory, neurotrophic profiles and total antioxidant), body composition, physical fitness and quality of life (QoL) in individuals with MNCD according to NPS.

METHODS

The sample comprised 34 older adults (71.4% women; 74.06±6.03 yrs, with MNCD diagnosis) categorized according to 50th percentile [Low (≤12) or High (≥13)] for NPS (Neuropsychiatric Inventory Questionnaire). Sociodemographic, clinical data, body composition, anthropometric, cognitive assessment (ADAS-Cog), physical fitness (Senior Fitness Test), QoL (QoL-Alzheimer's Disease scale) were evaluated, and blood samples were collected for biochemical analysis.

RESULTS

Low compared to high NPS group showed higher levels of IL-6, IGF-1and neurotrophic zscore (composite of IGF-1, VEGF-1, BDNF). Additionally, low compared to high NPS group have higher QoL, aerobic fitness and upper body and lower body strength.

CONCLUSION

The severity of NPS seems to be related to modified neurotrophic and inflammatory outcomes, lower physical fitness, and poor QoL. Strategies to counteract NPS development may preserve the physical and mental health of individuals with MNCD.

.

IL-34 exacerbates pathogenic features of Alzheimer's disease and calvaria osteolysis in triple transgenic (3x-Tg) female mice

Hallmark features of Alzheimer's disease (AD) include elevated accumulation of aggregated Aβ40 and Aβ42 peptides, hyperphosphorylated Tau (p-Tau), and neuroinflammation. Emerging evidence indicated that interleukin-34 (IL-34) contributes to AD and inflammatory osteolysis via the colony-stimulating factor-1 receptor (CSF-1r). In addition, CSF-1r is also activated by macrophage colony-stimulating factor-1 (M-CSF). While the role of M-CSF in bone physiology and pathology is well addressed, it remains controversial whether IL-34-mediated signaling promotes osteolysis, neurodegeneration, and neuroinflammation in relation to AD. In this study, we injected 3x-Tg mice with mouse recombinant IL-34 protein over the calvaria bone every other day for 42 days. Then, behavioral changes, brain pathology, and calvaria osteolysis were evaluated using various behavioral maze and histological assays. We demonstrated that IL-34 administration dramatically elevated AD-like anxiety and memory loss, pathogenic amyloidogenesis, p-Tau, and RAGE expression in female 3x-Tg mice. Furthermore, IL-34 delivery promoted calvaria inflammatory osteolysis compared to the control group. In addition, we also compared the effects of IL-34 and M-CSF on macrophages, microglia, and RANKL-mediated osteoclastogenesis in relation to AD pathology in vitro. We observed that IL-34-exposed SIM-A9 microglia and 3x-Tg bone marrow-derived macrophages released significantly elevated amounts of pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6, compared to M-CSF treatment in vitro. Furthermore, IL-34, but not M-CSF, elevated RANKL-primed osteoclastogenesis in the presence of Aβ40 and Aβ42 peptides in bone marrow derived macrophages isolated from female 3x-Tg mice. Collectively, our data indicated that IL-34 elevates AD-like features, including behavioral changes and neuroinflammation, as well as osteoclastogenesis in female 3x-Tg mice.

An Update on Apathy in Alzheimer's Disease

Apathy is a complex multi-dimensional syndrome that affects up to 70% of individuals with Alzheimer's disease (AD). Whilst many frameworks to define apathy in AD exist, most include loss of motivation or goal-directed behaviour as the central feature. Apathy is associated with significant impact on persons living with AD and their caregivers and is also associated with accelerated cognitive decline across the AD spectrum. Neuroimaging studies have highlighted a key role of fronto-striatial circuitry including the anterior cingulate cortex (ACC), orbito-frontal cortex (OFC) and associated subcortical structures. Importantly, the presence and severity of apathy strongly correlates with AD stage and neuropathological biomarkers of amyloid and tau pathology. Following from neurochemistry studies demonstrating a central role of biogenic amine neurotransmission in apathy syndrome in AD, recent clinical trial data suggest that apathy symptoms may improve following treatment with agents such as methylphenidate-which may have an important role alongside emerging non-pharmacological treatment strategies. Here, we review the diagnostic criteria, rating scales, prevalence, and risk factors for apathy in AD. The underlying neurobiology, neuropsychology and associated neuroimaging findings are reviewed in detail. Finally, we discuss current treatment approaches and strategies aimed at targeting apathy syndrome in AD, highlighting areas for future research and clinical trials in patient cohorts.

The Interface between Depression and Alzheimer's Disease. A Comprehensive Approach

Depression and Alzheimer's disease (AD) are frequent interacting diseases in the elderly with a negative impact on the quality of life of patients and caregivers. Late-life depression may be regarded either as an early symptom of AD or a risk factor for AD, depending on the context. This review was focused on the latest developments in the fields of the neurobiological basis and treatment of depression in AD. We found that some plausible hypotheses are emerging to correlate with depression in AD, such as neuroinflammation and dysimmune regulation. It seems that depression is not related to amyloid deposition, but this issue is not completely resolved. The response to antidepressants is controversial according to the evidence from 10 small double-blind randomized placebo-controlled clinical trials with antidepressants in AD patients with depression: four with sertraline, one with three arms (sertraline, mirtazapine, placebo), one with fluoxetine, one with imipramine, one with clomipramine, one with escitalopram, and one with vortioxetine. The total number of treated patients completing the trials was 638. The main criterion of a positive response was a reduction in the scores of clinical scales for depression of at least 50%. The weighted OR (odds ratio) was calculated with the method of Mantel-Haenszel: 1.29; 95% CI: 0.77-2.16. No significant differences were found compared with placebo. Antidepressants did not have a meaningful negative influence on cognition, which was measured with the mini-mental state examination (MMSE) in 18 clinical trials. Alternatives other than drugs are also discussed. Although there have been important advances in this field, pathophysiology and treatment deserve further research.

Blood plasma protein profiles of neuropsychiatric symptoms and related cognitive decline in older people

Neuropsychiatric symptoms (NPS) severely affect patients and their caregivers, and are associated with worse long-term outcomes. This study tested the hypothesis that altered protein levels in blood plasma could serve as biomarkers of NPS; and that altered protein levels are associated with persisting NPS and cognitive decline over time. We performed a cross-sectional and longitudinal study in older subjects with cognitive impairment and cognitively unimpaired in a memory clinic setting. NPS were recorded through the Neuropsychiatric Inventory Questionnaire (NPI-Q) while cognitive and functional impairment was assessed using the clinical dementia rating sum of boxes (CDR-SoB) score at baseline and follow-up visits. Shotgun proteomic analysis based on liquid chromatography-mass spectrometry was conducted in blood plasma samples, identifying 420 proteins. The presence of Alzheimer's Disease (AD) pathology was determined by cerebrospinal fluid biomarkers. Eighty-five subjects with a mean age of 70 (±7.4) years, 62% female and 54% with mild cognitive impairment or mild dementia were included. We found 15 plasma proteins with altered baseline levels in participants with NPS (NPI-Q score > 0). Adding those 15 proteins to a reference model based on clinical data (age, CDR-SoB) significantly improved the prediction of NPS (from receiver operating characteristic area under the curve [AUC] 0.75 to AUC 0.91, p = 0.004) with a specificity of 89% and a sensitivity of 74%. The identified proteins additionally predicted both persisting NPS and cognitive decline at follow-up visits. The observed associations were independent of the presence of AD pathology. Using proteomics, we identified a panel of specific blood proteins associated with current and future NPS, and related cognitive decline in older people. These findings show the potential of untargeted proteomics to identify blood-based biomarkers of pathological alterations relevant for NPS and related clinical disease progression.

Efficacy and safety of blood derivatives therapy in Alzheimer's disease: a systematic review and meta-analysis

BACKGROUND

Blood derivatives therapy is a conventional clinical treatment, while the treatment for Alzheimer's disease (AD) is relatively novel. To provide clinical references for treating AD, this meta-analysis was performed to evaluate the efficacy and safety of blood derivatives therapy on the patients with AD.

METHODS

A systematic articles search was performed for eligible studies published up to December 6, 2021 through the PubMed, Embase, Cochrane library, ClinicalTrials.gov , Chinese National Knowledge Infrastructure database, and Wanfang databases. The included articles were screened by using rigorous inclusion and exclusion criteria. Study selection and data-extraction were performed by two authors independently. Random effects model or fixed effects model was used. Quality of studies and risk of bias were evaluated according to the Cochrane risk of bias tool. All analyses were conducted using Review Manager 5.4. The study was designed and conducted according to the Preferring Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline.

RESULTS

A total of three plasma administrations (two plasma exchange and one young plasma infusion) and five intravenous immunoglobulin (IVIG) randomized controlled trials with a sample size of 1148 subjects diagnosed with AD were included. There was no significant difference in cognitive improvement and all-cause discontinuation between intervention and placebo groups (RR 1.10, 95% CI 0.79-1.54). And Intervention groups showed not a statistically significant improvement in cognition of included subjects measured by the ADAS-Cog (MD 0.36, 95% CI 0.87-1.59), ADCS-ADL (MD -1.34, 95% CI - 5.01-2.32) and NPI (MD 2.20, 95% CI 0.07-4.32) score compared to the control groups. IVIG is well tolerated for AD patients even under the maximum dose (0.4 g/kg), but it is inferior to placebo in Neuropsychiatric Inventory scale in AD patients (MD 2.19, 95% CI 0.02-4.37).

CONCLUSIONS

The benefits of blood derivatives therapy for AD are limited. It is necessary to perform well-designed randomized controlled trials with large sample sizes focusing on the appropriate blood derivatives for the specific AD sub-populations in the future.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021233886.

Alzheimer's Disease-Related Psychosis: An Overview of Clinical Manifestations, Pathogenesis, and Current Treatment

Behavioral and psychotic manifestations, including aggression, delusions, and hallucinations, are frequent comorbidities in patients with debilitating nervous illnesses such as Alzheimer's disease (AD), Amyotrophic Lateral Sclerosis, Multiple Sclerosis, and Parkinson's disease. AD-related psychosis may be linked to a poor disease prognosis, highlighting that early detection and management are mandatory. The manifestations are variable and may be very heterogeneous, imposing a real diagnostic issue. Some assessment tools such as BEHAVE-AD, CERAD-BRSD, and the Psycho-Sensory Hallucinations Scale have been designed to facilitate the diagnosis. The mechanisms behind neurodegeneration-related psychosis are complex and are not fully understood, imposing a burden on researchers to find appropriate management modalities. Familial history and some genetic disturbances may have a determinant role in these delusions and hallucinations in cases with AD. The loss of neuronal cells, atrophy in some regions of the central nervous, and synaptic dysfunction may also contribute to these comorbidities. Furthermore, inflammatory disturbances triggered by pro-inflammatory agents such as interleukins and tumor necrosis factors are stratified among the potential risk factors of the onset of numerous psychotic symptoms in Alzheimer's patients. Little is known about the possible management tools; therefore, it is urgent to conduct well-designed trials to investigate pharmacological and non-pharmacological interventions that can improve the care process of these patients. This review summarizes the current findings regarding the AD-related psychosis symptoms, pathological features, assessment, and management.

Behavioral and Psychological Symptoms of Dementia as a Means of Communication: Considerations for Reducing Stigma and Promoting Person-Centered Care

Dementia has rapidly become a major global health crisis. As the aging population continues to increase, the burden increases commensurately on both individual and societal levels. The behavioral and psychological symptoms of dementia (BPSD) are a prominent clinical feature of Alzheimer’s disease and related dementias (ADRD). BPSD represent a myriad of manifestations that can create significant challenges for persons living with dementia and their care providers. As such, BPSD can result in detriments to social interaction with others, resulting in harm to the psychosocial health of the person with dementia. While brain deterioration can contribute to BPSD as the disease progresses, it may be confounded by language and communication difficulties associated with ADRD. Indeed, when a person with dementia cannot effectively communicate their needs, including basic needs such as hunger or toileting, nor symptoms of pain or discomfort, it may manifest as BPSD. In this way, a person with dementia may be attempting to communicate with what little resources are available to them in the form of emotional expression. Failing to recognize unmet needs compromises care and can reduce quality of life. Moreover, failing to fulfill said needs can also deteriorate communication and social bonds with loved ones and caregivers. The aim of this review is to bring the differential of unmet needs to the forefront of BPSD interpretation for both formal and informal caregivers. The overarching goal is to provide evidence to reframe the approach with which caregivers view the manifestations of BPSD to ensure quality of care for persons with dementia. Understanding that BPSD may, in fact, be attempts to communicate unmet needs in persons with dementia may facilitate clinical care decisions, promote quality of life, reduce stigma, and foster positive communications.

Neuropsychiatric Symptoms in Dementia: Considering a Clinical Role for Electroencephalography

OBJECTIVE

Degenerative dementia is characterized by progressive cognitive decline and neuropsychiatric symptoms. People with Alzheimer's disease (AD), the most common cause of dementia, show synaptic loss and disruption of functional brain networks along with neuritic plaques and neurofibrillary tangles. Electroencephalography (EEG) directly reflects synaptic activity, and among patients with AD it is associated with slowing of background activity. The purpose of this study was to identify associations between neuropsychiatric symptoms and EEG in patients with dementia and to determine whether EEG parameters could be used for clinical assessment of pharmacological treatment of neuropsychiatric symptoms in dementia (NPSD) with galantamine or risperidone.

METHODS

Seventy-two patients with EEG recordings and a score ≥10 on the Neuropsychiatric Inventory (NPI) were included. Clinical assessments included administration of the NPI, the Mini-Mental State Examination (MMSE), and the Cohen-Mansfield Agitation Inventory (CMAI). Patients underwent EEG examinations at baseline and after 12 weeks of treatment with galantamine or risperidone. EEG frequency analysis was performed. Correlations between EEG and assessment scale scores were statistically examined, as were EEG changes from baseline to the week 12 visit and the relationship with NPI, CMAI, and MMSE scores.

RESULTS

Significant correlations were found between NPI agitation and delta EEG frequencies at baseline and week 12. No other consistent and significant relationships were observed between NPSD and EEG at baseline, after NPSD treatment, or in the change in EEG from baseline to follow-up.

CONCLUSIONS

The limited informative findings in this study suggest that there exists a complex relationship between NPSD and EEG; hence, it is difficult to evaluate and use EEG for clinical assessment of pharmacological NPSD treatment.

Cerebrospinal Fluid Proteome Alterations Associated with Neuropsychiatric Symptoms in Cognitive Decline and Alzheimer's Disease

Although neuropsychiatric symptoms (NPS) are common and severely affect older people with cognitive decline, little is known about their underlying molecular mechanisms and relationships with Alzheimer’s disease (AD). The aim of this study was to identify and characterize cerebrospinal fluid (CSF) proteome alterations related to NPS. In a longitudinally followed-up cohort of subjects with normal cognition and patients with cognitive impairment (MCI and mild dementia) from a memory clinic setting, we quantified a panel of 790 proteins in CSF using an untargeted shotgun proteomic workflow. Regression models and pathway enrichment analysis were used to investigate protein alterations related to NPS, and to explore relationships with AD pathology and cognitive decline at follow-up visits. Regression analysis selected 27 CSF proteins associated with NPS. These associations were independent of the presence of cerebral AD pathology (defined as CSF p-tau181/Aβ1−42 > 0.0779, center cutoff). Gene ontology enrichment showed abundance alterations of proteins related to cell adhesion, immune response, and lipid metabolism, among others, in relation to NPS. Out of the selected proteins, three were associated with accelerated cognitive decline at follow-up visits after controlling for possible confounders. Specific CSF proteome alterations underlying NPS may both represent pathophysiological processes independent from AD and accelerate clinical disease progression.

Adenosine Receptors in Neuropsychiatric Disorders: Fine Regulators of Neurotransmission and Potential Therapeutic Targets

Adenosine exerts an important role in the modulation of central nervous system (CNS) activity. Through the interaction with four G-protein coupled receptor (GPCR) subtypes, adenosine subtly regulates neurotransmission, interfering with the dopaminergic, glutamatergic, noradrenergic, serotoninergic, and endocannabinoid systems. The inhibitory and facilitating actions of adenosine on neurotransmission are mainly mediated by A₁ and A_2A adenosine receptors (ARs), respectively. Given their role in the CNS, ARs are promising therapeutic targets for neuropsychiatric disorders where altered neurotransmission represents the most likely etiological hypothesis. Activating or blocking ARs with specific pharmacological agents could therefore restore the balance of altered neurotransmitter systems, providing the rationale for the potential treatment of these highly debilitating conditions. In this review, we summarize and discuss the most relevant studies concerning AR modulation in psychotic and mood disorders such as schizophrenia, bipolar disorders, depression, and anxiety, as well as neurodevelopment disorders such as autism spectrum disorder (ASD), fragile X syndrome (FXS), attention-deficit hyperactivity disorder (ADHD), and neuropsychiatric aspects of neurodegenerative disorders.

Blood-based biomarkers of agitation in Alzheimer's disease: Advances and future prospects

Agitation is a common neuropsychiatric symptom that becomes more prevalent as Alzheimer's disease (AD) increases in severity. The treatment of agitation is an urgent and unmet need due to the poor outcomes associated with it, its disruptive impact on patients and caregivers, and the lack of efficacious and safe treatments. Recent research on agitation in AD with blood-based biomarkers has advanced the search for its biomarkers beyond the brain and provides new insights to understand its mechanisms and improve treatments. Here, we reviewed studies of blood-based biomarkers of agitation in AD, which show that inflammatory biomarkers are increased in patients with agitation, may predict the development of agitation, and are associated with symptom severity. In addition, they may also track symptom severity and response to treatment. Other biomarkers associated with agitation include markers of oxidative stress, brain cholesterol metabolism, motor activity, and clusterin, a chaperone protein. These results are promising and need to be replicated. Preliminary evidence suggests a role for these biomarkers in interventional studies for agitation to predict and monitor treatment response, which may eventually help enrich study samples and deliver therapy likely to benefit individual patients. Advances in blood-based biomarkers of AD including those identified in "-omic" studies and high sensitivity assays provide opportunities to identify new biomarkers of agitation. Future studies of agitation and its treatment should investigate blood-based biomarkers to yield novel insights into the neurobiological mechanisms of agitation, monitoring symptoms and response to treatment, and to identify patients likely to respond to treatments.

Effects of Peroral Omega-3 Fatty Acid Supplementation on Cerebrospinal Fluid Biomarkers in Patients with Alzheimer's Disease: A Randomized Controlled Trial-The OmegAD Study

BACKGROUND

Studies have suggested a connection between a decrease in the levels of polyunsaturated fatty acids (PUFAs) and Alzheimer's disease (AD). We aimed to assess the effect of supplementation with omega-3 fatty acids (n-3 FAs) on biomarkers analyzed in the cerebrospinal fluid (CSF) of patients diagnosed with AD.

OBJECTIVE

To investigate the effects of daily supplementation with 2.3 g of PUFAs in AD patients on the biomarkers in CSF described below. We also explored the possible correlation between these biomarkers and the performance in the cognitive test Mini-Mental State Examination (MMSE).

METHODS

Thirty-three patients diagnosed with AD were randomized to either treatment with a daily intake of 2.3 g of n-3 FAs (n  =  18) or placebo (n  =  15). CSF samples were collected at baseline and after six months of treatment, and the following biomarkers were analyzed: Aβ 38, Aβ 40, Aβ 42, t-tau, p-tau, neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), soluble IL-1 receptor type II (sIL-1RII), and IL-6.

RESULTS

There were no significant differences between the groups concerning the level of the different biomarkers in the CSF at baseline. Within the treatment group, there was a small but significant increase in both YKL-40 (p = 0.04) and NfL (p = 0.03), while the other CSF biomarkers remained stable.

CONCLUSION

Supplementation with n-3 FAs had a statistically significant effect on NfL and YKL-40, resulting in an increase of both biomarkers, indicating a possible increase of inflammatory response and axonal damage. This increase in biomarkers did not correlate with MMSE score.

Promising Intervention Approaches to Potentially Resolve Neuroinflammation And Steroid Hormones Alterations in Alzheimer's Disease and Its Neuropsychiatric Symptoms

Neuroinflammation is a biological process by which the central nervous system responds to stimuli/injuries affecting its homeostasis. So far as this reactive response becomes exacerbated and uncontrolled, it can lead to neurodegeneration, compromising the cognitive and neuropsychiatric domains. Parallelly, modifications in the hypothalamic signaling of neuroprotective hormones linked also to the inflammatory responses of microglia and astrocytes can exacerbate these processes. To complicate the picture, modulations in the gut microbiota (GM) can induce changes in neuroinflammation, altering cognitive and neuropsychiatric functioning. We conducted a web-based search on PubMed. We described studies regarding the cross-talk among microglia and astrocytes in the neuroinflammation processes, along with the role played by the steroid hormones, and how this can reflect on cognitive decline/neurodegeneration, in particular on Alzheimer's Disease (AD) and its neuropsychiatric manifestations. We propose and support the huge literature showing the potentiality of complementary/alternative therapeutic approaches (nutraceuticals) targeting the sustained inflammatory response, the dysregulation of hypothalamic system and the GM composition. NF-κB and Keap1/Nrf2 are the main molecular targets on which a list of nutraceuticals can modulate the altered processes. Since there are some limitations, we propose a new intervention natural treatment in terms of Oxygen-ozone (O2-O3) therapy that could be potentially used for AD pathology. Through a meta-analytic approach, we found a significant modulation of O3 on inflammation-NF-κB/NLRP3 inflammasome/Toll-Like Receptor 4 (TLR4)/Interleukin IL-17α signalling, reducing mRNA (p<0.00001 Odd Ratio (OR)=-5.25 95% CI:-7.04/-3.46) and protein (p<0.00001 OR=-4.85 95%CI:-6.89/-2.81) levels, as well as on Keap1/Nrf2 pathway. Through anti-inflammatory, immune, and steroid hormones modulation and anti-microbial activities, O3 at mild therapeutic concentrations potentiated with nutraceuticals and GM regulators could determine combinatorial effects impacting on cognitive and neurodegenerative domains, neuroinflammation and neuroendocrine signalling, directly or indirectly through the mediation of GM.

Brain mechanisms underlying neuropsychiatric symptoms in Alzheimer's disease: a systematic review of symptom-general and -specific lesion patterns

Neuropsychiatric symptoms (NPSs) are common in patients with Alzheimer's disease (AD) and are associated with accelerated cognitive impairment and earlier deaths. This review aims to explore the neural pathogenesis of NPSs in AD and its association with the progression of AD. We first provide a literature overview on the onset times of NPSs. Different NPSs occur in different disease stages of AD, but most symptoms appear in the preclinical AD or mild cognitive impairment stage and develop progressively. Next, we describe symptom-general and -specific patterns of brain lesions. Generally, the anterior cingulate cortex is a commonly damaged region across all symptoms, and the prefrontal cortex, especially the orbitofrontal cortex, is also a critical region associated with most NPSs. In contrast, the anterior cingulate-subcortical circuit is specifically related to apathy in AD, the frontal-limbic circuit is related to depression, and the amygdala circuit is related to anxiety. Finally, we elucidate the associations between the NPSs and AD by combining the onset time with the neural basis of NPSs.

Blood DNA Methylation Levels in the WNT5A Gene Promoter Region: A Potential Biomarker for Agitation in Subjects with Dementia

Background:

Behavioral and psychological symptoms of dementia (BPSD) cause a heavy burden for both patient and caregivers. These symptoms are diverse, and their mechanism is still unclear. Agitation is the most common and difficult to treat among BPSD. In recent years, while changes in DNA methylation levels have been receiving attention as a biomarker of aging and dementia, associations with BPSD have not been examined.

Objective:

Focusing on agitation, the objective of the present study was to identify a region where changes in DNA methylation levels are associated with agitation.

Methods:

Using genome-wide DNA methylation analysis data for 7 dementia subjects with agitation, 5 dementia subjects without agitation, and 4 normal elderly controls, we determined a signaling pathway in the WNT5A gene promoter region to be associated with agitation. Based on this result, we measured DNA methylation levels in this region for 26 dementia subjects with agitation and 82 dementia subjects without agitation by means of methylation-sensitive high-resolution melting (MS-HRM) analysis.

Results:

The WNT5A DNA methylation level in dementia subjects with agitation was significantly lower than in those without agitation (p = 0.001). Changes in WNT5A DNA methylation levels were not influenced by age, sex, body mass index, APOE ɛ4, medication, or inflammatory cytokines.

Conclusion:

Our results suggested an association of agitation with Wnt signaling, in particular with changes in WNT5A DNA methylation levels, which could be a potentially useful biomarker for predicting the appearance of agitation. It may contribute to the elucidation of the mechanism of BPSD.

The Role of Heart Rate Variability in the Future of Remote Digital Biomarkers

Heart rate variability (HRV) offers insights into humoral, neural and neurovisceral processes in health and disorders of brain, body and behavior but has yet to be fully potentiated in the digital age. Remote measurement technologies (RMTs), such as, smartphones, wearable sensors or home-based devices, can passively capture HRV as a nested parameter of neurovisceral integration and health during everyday life, providing insights across different contexts, such as activities of daily living, therapeutic interventions and behavioral tasks, to compliment ongoing clinical care. Many RMTs measure HRV, even consumer wearables and smartphones, which can be deployed as wearable sensors or digital cameras using photoplethysmography. RMTs that measure HRV provide the opportunity to identify digital biomarkers indicative of changes in health or disease status in disorders where neurovisceral processes are compromised. RMT-based HRV therefore has potential as an adjunct digital biomarker in neurovisceral digital phenotyping that can add continuously updated, objective and relevant data to existing clinical methodologies, aiding the evolution of current "diagnose and treat" care models to a more proactive and holistic approach that pairs established markers with advances in remote digital technology.

Agitation and impulsivity in mid and late life as possible risk markers for incident dementia

To identify knowledge gaps regarding new-onset agitation and impulsivity prior to onset of cognitive impairment or dementia the International Society to Advance Alzheimer's Research and Treatment Neuropsychiatric Syndromes (NPS) Professional Interest Area conducted a scoping review. Extending a series of reviews exploring the pre-dementia risk syndrome Mild Behavioral Impairment (MBI), we focused on late-onset agitation and impulsivity (the MBI impulse dyscontrol domain) and risk of incident cognitive decline and dementia. This scoping review of agitation and impulsivity pre-dementia syndromes summarizes the current biomedical literature in terms of epidemiology, diagnosis and measurement, neurobiology, neuroimaging, biomarkers, course and prognosis, treatment, and ongoing clinical trials. Validations for pre-dementia scales such as the MBI Checklist, and incorporation into longitudinal and intervention trials, are needed to better understand impulse dyscontrol as a risk factor for mild cognitive impairment and dementia.

Agitation, Oxidative Stress, and Cytokines in Alzheimer Disease: Biomarker Analyses From a Clinical Trial With Nabilone for Agitation

The endocannabinoid system has been a target of interest for agitation in Alzheimer disease (AD) because of potential behavioral effects and its potential impact on mechanisms implicated in AD such as oxidative stress (OS) and neuroinflammation. We explored whether serum markers of OS and neuroinflammation were associated with response to the cannabinoid nabilone in agitated patients with AD (N = 38). All participants were enrolled in a 14-week, double-blind, cross-over trial comparing nabilone to placebo (6 weeks each) with a 1-week washout between phases. Samples were collected at the start and end of each phase. The cross-sectional relationship agitation (Cohen Mansfield Agitation Inventory) and OS and inflammatory markers were investigated to select markers of interest. Significant markers were then explored for their relationship with response. The OS marker, 4-hydroxynonenal (4-HNE; F_{1, 35} = 6.41, P = .016), and the proinflammatory cytokine, tumor necrosis factor-α (TNF-α; F_{1, 29} = 3.97, P = .06), were associated with agitation severity, and TNF-α remained significantly associated (F_{2, 25} = 3.69, P = .04) after adjustment for cognition. In the placebo phase, lower baseline 4-HNE was associated with decreases in agitation severity only (b = 0.01, P = .01), while lower baseline TNF-α was associated with decreases in agitation severity in the nabilone phase only (b = 1.14, P = .045). Changes in 4-HNE were not associated with changes in agitation severity in either phase. In the nabilone phase, lower baseline TNF-α was associated with decreases in agitation severity (b = 1.14, P = .045), and decreases in TNF-α were associated with decreases in agitation severity (b = 1.12, P = .006). These findings suggest that OS and neuroinflammation may be associated with agitation severity, while nabilone may have anti-inflammatory effects.

Protective Effects of Quercetin on Anxiety-Like Symptoms and Neuroinflammation Induced by Lipopolysaccharide in Rats

Recently, neuroinflammation is thought to be one of the important causes of many neuropsychiatric diseases. Quercetin (QUER) is a natural flavonoid, and it is well known that QUER has antioxidative, anti-inflammatory, and neuroprotective effects. In our study, lipopolysaccharide (LPS) was injected into the lateral ventricle of rats to induce anxiety-like behaviors and neuroinflammation, and it was confirmed that chronic administration of QUER could improve anxiety-like symptoms. We also investigated the effects of QUER on inflammatory markers and its major mechanisms associated with inflammation in the hippocampus. Daily administration of QUER (10, 50, and 100 mg/kg) daily for 21 days significantly improved anxiety-like behaviors in the elevated plus-maze test and open field test. QUER administration significantly reduced inflammatory markers such as interleukin-6, interleukin-1β, cyclooxygenase-2, and nuclear factor-kappaB levels in the brain. In addition, QUER significantly increased the brain-derived neurotrophic factor (BDNF) mRNA level and decreased the nitric oxide synthase (iNOS) mRNA level. Therefore, our results have shown that QUER can improve anxiety-like behaviors caused by chronic neuroinflammation. This anxiolytic effect of QUER has been shown to be due to its anti-inflammatory effects and appropriate regulation of BDNF and iNOS expression. Thus, QUER provides the potential as a therapeutic agent to inhibit anxiety-like symptoms in neuropsychiatric diseases, such as anxiety.

Apathy as a behavioural marker of cognitive impairment in Parkinson's disease: a longitudinal analysis

Background

Understanding the longitudinal course of non-motor symptoms, and finding markers to predict cognitive decline in Parkinson’s disease (PD), are priorities. Previous work has demonstrated that apathy is one of the only behavioural symptoms that differentiates people with PD and intact cognition from those with mild cognitive impairment (MCI-PD). Other psychiatric symptoms emerge as dementia in PD develops.

Objective

We explored statistical models of longitudinal change to detect apathy as a behavioural predictor of cognitive decline in PD.

Methods

We followed 104 people with PD intermittently over 2 years, undertaking a variety of motor, behavioural and cognitive measures. We applied a linear mixed effects model to explore behavioural factors associated with cognitive change over time. Our approach goes beyond conventional modelling based on a random-intercept and slope approach, and can be used to examine the variability in measures within individuals over time.

Results

Global cognitive scores worsened during the two-year follow-up, whereas the longitudinal evolution of self-rated apathy scores and other behavioural measures was negligible. Level of apathy was negatively (− 0.598) correlated with level of cognitive impairment and participants with higher than average apathy scores at baseline also had poorer cognition. The model indicated that departure from the mean apathy score at any point in time was mirrored by a corresponding departure from average global cognitive score.

Conclusion

High levels of apathy are predictive of negative cognitive and behavioural outcomes over time, suggesting that apathy may be a behavioural indicator of early cognitive decline. This has clinical and prognostic implications.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09538-z) contains supplementary material, which is available to authorized users.

Apolipoprotein E and affective symptoms in mild cognitive impairment and Alzheimer's disease dementia: A systematic review and meta-analysis

OBJECTIVE

APOE status has been associated to affective symptoms in cognitively impaired subjects, with conflicting results.

METHODS

Databases CINAHL, Embase, PsychINFO and PubMed were searched for studies evaluating APOE genotype with affective symptoms in MCI and AD dementia. Symptoms were meta-analyzed separately and possible sources of heterogeneity were examined.

RESULTS

Fifty-three abstracts fulfilled the eligibility criteria. No association was found between the individual symptoms and APOE ε4 carriership or zygosity. For depression and anxiety, only pooled unadjusted estimates showed positive associations with between-study heterogeneity, which could be explained by variation in study design, setting and way of symptom assessment.

CONCLUSIONS

There is no evidence that APOE ε4 carriership or zygosity is associated with the presence of depression, anxiety, apathy, agitation, irritability or sleep disturbances in cognitively impaired subjects. Future research should shift its focus from this single polymorphism to a more integrated view of other biological factors.

Aging exacerbates cognitive and anxiety alterations induced by an intracerebroventricular injection of amyloid-β1-42 peptide in mice

An increasing body of evidence indicates that the activation of indoleamine-2,3-dyoxigenase (IDO), a first and rate-limiting enzyme in the kynurenine (KYN) pathway, is involved in Aβ_1-42-neurotoxicity and AD pathogenesis. We have reported for the first time that brain IDO activation is related to Aβ_1-42 exposure in young mice. Because aging is characterized by a brain dyshomeostasis and because it remains the most dominant risk factor for AD, the purpose of this study was to determine whether aging is associated with a higher sensitivity to behavioural and neurochemical alterations elicited by an intracerebroventricular (i.c.v.) injection of Aβ_1-42 (400 pmol/mice), and whether KYN pathway is involved in these effects. We confirmed that aged mice displayed higher cognitive deficit in the object recognition test and higher anxiety-like behaviour in the elevated plus-maze and open field tests after the Aβ_1-42 administration. Aged mice also responded to Aβ_1-42 with a higher deficiency of brain-derived neurotrophic factor, glutathione levels and total radical-trapping antioxidant capacity, a higher IDO activity, and a higher KYN and KYN/tryptophan ratio in the prefrontal cortex and hippocampus. These effects of Aβ_1-42 were associated with a higher proinflammatory status, as measured by higher levels of interleukin-6, lower levels of interleukin-10 and higher expression of glial fibrillary acidic protein (GFAP) and allograft inflammatory factor 1 (Iba1) in the brain of aged mice. These results represent primary evidence suggesting that age-associated inflammatory signature and down-regulation of neuroprotectants in the brain render aged mice more vulnerable to Aβ_1-42-induced memory loss, anxiety symptoms and KYN pathway dysregulation.

Neuropsychiatric symptoms in Alzheimer's disease: associations with caregiver burden and treatment outcomes

BACKGROUND

Caregivers play a major role in providing care for patients with Alzheimer's disease (AD) and are themselves at higher risk of health comorbidities.

AIM

To address the impact of neuropsychiatric symptoms of patients in different stages of AD on their caregivers' burden.

DESIGN

This prospective study enrolled 260 AD patients with clinical dementia rating (CDR) of 0.5, 1 and 2 at a tertiary medical center.

METHODS

All patients were tested using the mini-mental state examination (MMSE), the cognitive abilities screening instrument (CASI), the neuropsychiatric inventory (NPI) and the CDR scale. Data regarding therapeutic outcomes of anti-Alzheimer's drugs were also collected. Caregivers were tested using NPI.

RESULTS

The mean follow-up interval was 25.0 ± 12.2 months, and two patients died during follow-up. NPI-burden was positively correlated with NPI-sum ( r  = 0.822, P  <   0.001) but negatively correlated with years of education ( r  = -0.140, P  =   0.024), CASI score ( r  = -0.259, P  <   0.001) and MMSE score ( r  = -0.262, P  <0.001). Multiple linear regression analysis showed that only NPI-sum was independently associated with mean NPI-burden. Both higher mean CASI and MMSE scores had better therapeutic outcome of anti-Alzheimer's drugs ( P  =   0.001 and P =   0.005, respectively).

CONCLUSIONS

The severity of neuropsychiatric symptoms in patients with AD was positively associated with caregiver's stress, and patients with better cognitive functions, under treatment with anti-Alzheimer's drugs, had better therapeutic outcomes. To reduce the impact of neuropsychiatric symptoms, it is crucial to detect dementia in its early phases and provide early intervention with anti-Alzheimer's drugs, which might help decrease the caregiver burden, thereby improving their quality of life.

Deficiency in EP4 Receptor-Associated Protein Ameliorates Abnormal Anxiety-Like Behavior and Brain Inflammation in a Mouse Model of Alzheimer Disease

Microglia are thought to play key roles in the progression of Alzheimer disease (AD). Overactivated microglia produce proinflammatory cytokines, such as tumor necrosis factor-α, which appear to contribute to disease progression. Previously, we reported that prostaglandin E₂ type 4 receptor-associated protein (EPRAP) promotes microglial activation. We crossed human amyloid precursor protein transgenic mice from strain J20^+/- onto an EPRAP-deficient background to determine the role of EPRAP in AD. Behavioral tests were performed in 5-month-old male J20^+/-EPRAP^+/+ and J20^+/-EPRAP^-/- mice. EPRAP deficiency reversed the reduced anxiety of J20^+/- mice but did not affect hyperactivity. No differences in spatial memory were observed between J20^+/-EPRAP^+/+ and J20^+/-EPRAP^-/- mice. In comparison with J20^+/-EPRAP^+/+, J20^+/-EPRAP^-/- mice exhibited less microglial accumulation and reductions in the Cd68 and tumor necrosis factor-α mRNAs in the prefrontal cortex and hippocampus. No significant differences were found between the two types of mice in the amount of amyloid-β 40 or 42 in the cortex and hippocampus. J20^+/-EPRAP^-/- mice reversed the reduced anxiety-like behavior and had reduced microglial activation compared with J20^+/-EPRAP^+/+ mice. Further research is required to identify the role of EPRAP in AD, but our results indicate that EPRAP may be related to behavioral and psychological symptoms of dementia and inflammation in patients with AD.

Indoleamine-2,3-dioxygenase mediates neurobehavioral alterations induced by an intracerebroventricular injection of amyloid-β1-42 peptide in mice

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by a progressive cognitive decline along with various neuropsychiatric symptoms, including depression and anxiety. Increasing evidence has been proposed the activation of the tryptophan-degrading indoleamine-2,3-dyoxigenase (IDO), the rate-limiting enzyme of kynurerine pathway (KP), as a pathogenic factor of amyloid-beta (Aβ)-related inflammation in AD. In the current study, the effects of an intracerebroventricular (i.c.v.) injection of Aβ1-42 peptide (400pmol/mice; 3μl/site) on the regulation of KP biomarkers (IDO activity, tryptophan and kynurerine levels) and the impact of Aβ1-42 on neurotrophic factors levels were investigated as potential mechanisms linking neuroinflammation to cognitive/emotional disturbances in mice. Our results demonstrated that Aβ1-42 induced memory impairment in the object recognition test. Aβ1-42 also induced emotional alterations, such as depressive and anxiety-like behaviors, as evaluated in the tail suspension and elevated-plus maze tests, respectively. We observed an increase in levels of proinflammatory cytokines in the Aβ1-42-treated mice, which led to an increase in IDO activity in the prefrontal cortex (PFC) and the hippocampus (HC). The IDO activation subsequently increased kynurerine production and the kynurenine/tryptophan ratio and decreased the levels of neurotrophic factors in the PFC and HC, which contributed to Aβ-associated behavioral disturbances. The inhibition of IDO activation by IDO inhibitor 1-methyltryptophan (1-MT), prevented the development of behavioral and neurochemical alterations. These data demonstrate that brain IDO activation plays a key role in mediating the memory and emotional disturbances in an experimental model based on Aβ-induced neuroinflammation.

Alterations of the Neuroinflammatory Markers IL-6 and TRAIL in Alzheimer's Disease

Objective

We aimed to identify biomarkers of Alzheimer's disease (AD) in order to improve diagnostic accuracy at mild stage.

Methods

AD patients aged >50 years were included in the disease group. We evaluated the relationship between potential blood and cerebrospinal fluid inflammatory biomarkers, cognitive status, temporal lobe atrophy and disease severity. Inflammatory biomarkers including interleukin 6 (IL-6), IL-18, fractalkine and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) levels were measured. APOE genotypes were determined.

Results

We enrolled 41 subjects in the disease group and 40 subjects in the normal control group. The majority (88.9%) of subjects in the disease group had mild AD. Elevated levels of plasma IL-6 and decreased levels of plasma TRAIL in the disease group were noted. Plasma levels of IL-6 and TRAIL were significantly correlated with their cerebrospinal fluid levels.

Conclusion

Plasma IL-6 and TRAIL were identified as potential biomarkers of AD at an early stage.

Progresses in treating agitation: a major clinical challenge in Alzheimer's disease

INTRODUCTION

Treatment of neuropsychiatric symptoms (NPS) represents a major clinical challenge in Alzheimer's disease (AD). Agitation and aggression are frequently seen during institutionalization and increase patient morbidity and mortality and caregiver burden. Off-label use of atypical antipsychotics for treating agitation in AD showed only modest clinical benefits, with high side-effect burden and risk of mortality. Non-pharmacological treatment approaches have become the preferred first-line option. When such treatment fails, pharmacological options are often used. Therefore, there is an urgent need to identify effective and safe pharmacological treatments for efficiently treating agitation and aggression in AD and dementia.

AREAS COVERED

Emerging evidence on the neurobiological substrates of agitation in AD has led to several recent clinical trials of repositioned and novel therapeutics for these NPS in dementia as an alternative to antipsychotics. We operated a comprehensive literature search for published articles evaluating pharmacological interventions for agitation in AD, with a review of recent clinical trials on mibampator, dextromethorphan/quinidine, cannabinoids, and citalopram.

EXPERT OPINION

Notwithstanding the renewed interest for the pharmacological treatment of agitation in AD, progresses have been limited. A small number and, sometimes methodologically questionable, randomized controlled trials (RCTs) have produced disappointing results. However, recently completed RCTs on novel or repositioned drugs (mibampator, dextromethorphan/quinidine, cannabinoids, and citalopram) showed some promise in treating agitation in AD, but still with safety concerns. Further evidence will come from ongoing Phase II and III trials on promising novel drugs for treating these distressing symptoms in patients with AD and dementia.