Identify a shared neural circuit linking multiple neuropsychiatric symptoms with Alzheimer's pathology

Neuropsychiatric symptoms (NPS) are common in Alzheimer's disease (AD)-associated neurodegeneration. However, NPS lack a consistent relationship with AD pathology. It is unknown whether any common neural circuits can link these clinically disparate while mechanistically similar features with AD pathology. Here, we explored the neural circuits of NPS in AD-associated neurodegeneration using multivariate pattern analysis (MVPA) of resting-state functional MRI data. Data from 98 subjects (70 amnestic mild cognitive impairment and 28 AD subjects) were obtained. The top 10 regions differentiating symptom presence across NPS were identified, which were mostly the fronto-limbic regions (medial prefrontal cortex, caudate, etc.). These 10 regions' functional connectivity classified symptomatic subjects across individual NPS at 69.46-81.27%, and predicted multiple NPS (indexed by Neuropsychiatric Symptom Questionnaire-Inventory) and AD pathology (indexed by baseline and change of beta-amyloid/pTau ratio) all above 70%. Our findings suggest a fronto-limbic dominated neural circuit that links multiple NPS and AD pathology. With further examination of the structural and pathological changes within the circuit, the circuit may shed light on linking behavioral disturbances with AD-associated neurodegeneration.

Efficacy and mechanisms of combined aerobic exercise and cognitive training in mild cognitive impairment: study protocol of the ACT trial

BACKGROUND

Developing non-pharmacological interventions with strong potential to prevent or delay the onset of Alzheimer's disease (AD) in high-risk populations is critical. Aerobic exercise and cognitive training are two promising interventions. Aerobic exercise increases aerobic fitness, which in turn improves brain structure and function, while cognitive training improves selective brain function intensively. Hence, combined aerobic exercise and cognitive training may have a synergistic effect on cognition by complementary strengthening of different neural functions. Few studies have tested the effects of such a combined intervention, and the findings have been discrepant, largely due to varying doses and formats of the interventions.

METHODS/DESIGN

The purpose of this single-blinded, 2 × 2 factorial phase II randomized controlled trial is to test the efficacy and synergistic effects of a 6-month combined cycling and speed of processing training intervention on cognition and relevant mechanisms (aerobic fitness, cortical thickness, and functional connectivity in the default mode network) in older adults with amnestic mild cognitive impairment. This trial will randomize 128 participants equally to four arms: cycling and speed of processing, cycling only, speed of processing only, or attention control for 6 months, and then follow them for another 12 months. Cognition and aerobic fitness will be assessed at baseline and at 3, 6, 12, and 18 months; cortical thickness and functional connectivity at baseline and at 6, 12, and 18 months; Alzheimer's disease (AD) conversion at 6, 12, and 18 months. The specific aims are to (1) determine the efficacy and synergistic effects of the combined intervention on cognition over 6 months, (2) examine the underlying mechanisms of the combined intervention, and (3) calculate the long-term effect sizes of the combined intervention on cognition and AD conversion. The analysis will use intention-to-treat and linear mixed-effects modeling.

DISCUSSION

This trial will be among the first to test the synergistic effects on cognition and mechanisms (relevant to Alzheimer's-associated neurodegeneration) of a uniquely conceptualized and rigorously designed aerobic exercise and cognitive training intervention in older adults with mild cognitive impairment. It will advance Alzheimer's prevention research by providing precise effect-size estimates of the combined intervention.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03313895 . Registered on 18 October 2017.

Sex Differences in the Neuropsychiatric Symptoms of Patients With Alzheimer's Disease

The aim of this study was to describe sex differences in neuropsychiatric symptoms (NPSs) in patients with Alzheimer's disease (AD). Baseline scores on the Cohen-Mansfield Agitation Inventory, Neurobehavioral Rating Scale-Agitation subscale, and the Neuropsychiatric Inventory from patients with AD enrolled in a multicenter trial of citalopram for the treatment of agitation were analyzed. We found not only that patients with AD having agitation were likely to exhibit many other NPSs but also that the women in this study were more likely to exhibit a broader range of NPS than were the men. These results suggest greater heterogeneity in the clinical presentation of women compared to men, and thus in the potential targets for treatment in these patients. Further characterization of sex differences in NPS can inform future efforts aimed at establishing subtypes of patients for whom various treatment approaches will be most appropriate.

Attributable Cost of Dementia: Demonstrating Pitfalls of Ignoring Multiple Health Care System Utilization

OBJECTIVES

To determine dementia prevalence and costs attributable to dementia using Veterans Health Administration (VHA) data with and without Medicare data.

DATA SOURCES

VHA inpatient, outpatient, purchased care and other data and Medicare enrollment, claims, and assessments in fiscal year (FY) 2013.

STUDY DESIGN

Analyses were conducted with VHA data alone and with combined VHA and Medicare data. Dementia was identified from a VHA sanctioned list of ICD-9 diagnoses. Attributable cost of dementia was estimated using recycled predictions.

DATA COLLECTION

Veterans age 65 and older who used VHA and were enrolled in Traditional Medicare in FY 2013 (1.9 million).

PRINCIPAL FINDINGS

VHA records indicated the prevalence of dementia in FY 2013 was 4.8 percent while combined VHA and Medicare data indicated the prevalence was 7.4 percent. Attributable cost of dementia to VHA was, on average, $10,950 per veteran per year (pvpy) using VHA alone and $6,662 pvpy using combined VHA and Medicare data. Combined VHA and Medicare attributable cost of dementia was $11,285 pvpy. Utilization attributed to dementia using VHA data alone was lower for long-term institutionalization and higher for supportive care services than indicated in combined VHA and Medicare data.

CONCLUSIONS

Better planning for clinical and cost-efficient care requires VHA and Medicare to share data for veterans with dementia and likely more generally.

Temporospatial components of brain ERPs as biomarkers for Alzheimer's disease

Introduction

Developing biomarkers that distinguish individuals with Alzheimer's disease (AD) from those with normal cognition remains a crucial goal for improving the health of older adults. We investigated adding brain spatial information to temporal event-related potentials (ERPs) to increase AD identification accuracy over temporal ERPs alone.

Methods

With two-step principal components analysis, we applied multivariate analyses that incorporated temporal and spatial ERP information from a cognitive task. Discriminant analysis used temporospatial ERP scores to classify participants as belonging to either the AD or healthy control group.

Results

Temporospatial ERPs produced a cross-validated area under the curve of 0.84. Adding spatial information through a formal procedure significantly improves classification accuracy.

Discussion

A weighted combination of temporospatial ERP markers performs well in detecting AD. Because ERPs are noninvasive and inexpensive, they may be promising biomarkers for AD that can add functional information to other biomarker systems while providing the individual's probability of correct classification.

Insula and Inferior Frontal Gyrus' Activities Protect Memory Performance Against Alzheimer's Disease Pathology in Old Age

Apolipoprotein E (APOE) ɛ4 carriers and patients with amnestic mild cognitive impairment (MCI) have high risk of developing Alzheimer's disease (AD). The Scaffolding Theory of Aging and Cognition proposes that recruitment of additional frontal brain regions can protect cognition against aging. This thesis has yet to be fully tested in older adults at high risk for AD. In the present study, 75 older participants (mean age: 74 years) were included. Applying a voxel-wise approach, fractional amplitude of low-frequency fluctuations (fALFF) in resting-state functional neuroimaging data were analyzed as a function of APOEɛ4 status (carrier versus noncarrier) and clinical status (healthy control [HC] versus MCI) using a 2×2 analysis of covariance (ANCOVA). Measures of cognition and cerebrospinal fluid levels of amyloid- β were also obtained. Three frontal regions were identified with significant interaction effects using ANCOVA (corrected p < 0.01): left-insula, left-inferior frontal gyrus (IFG), and right-precentral gyrus. The HC/APOEɛ4 carrier group had significantly higher fALFF in all three regions than other groups. In the entire sample, for two regions (left insula and left IFG), a significant positive relationship between amyloid-β and memory was only observed among individuals with low fALFF. Our results suggest higher activity in frontal regions may explain being cognitively normal among a subgroup of APOEɛ4 carriers and protect against the negative impact of AD-associated pathology on memory. This is an observation with potential implications for AD therapeutics.

Cognitive and Neural Effects of Vision-Based Speed-of-Processing Training in Older Adults with Amnestic Mild Cognitive Impairment: A Pilot Study

OBJECTIVES

To examine the cognitive and neural effects of vision-based speed-of-processing (VSOP) training in older adults with amnestic mild cognitive impairment (aMCI) and contrast those effects with an active control (mental leisure activities (MLA)).

DESIGN

Randomized single-blind controlled pilot trial.

SETTING

Academic medical center.

PARTICIPANTS

Individuals with aMCI (N = 21).

INTERVENTION

Six-week computerized VSOP training.

MEASUREMENTS

Multiple cognitive processing measures, instrumental activities of daily living (IADLs), and two resting state neural networks regulating cognitive processing: central executive network (CEN) and default mode network (DMN).

RESULTS

VSOP training led to significantly greater improvements in trained (processing speed and attention: F1,19  = 6.61, partial η(2)  = 0.26, P = .02) and untrained (working memory: F1,19  = 7.33, partial η(2)  = 0.28, P = .01; IADLs: F1,19  = 5.16, partial η(2)  = 0.21, P = .03) cognitive domains than MLA and protective maintenance in DMN (F1, 9  = 14.63, partial η(2)  = 0.62, P = .004). VSOP training, but not MLA, resulted in a significant improvement in CEN connectivity (Z = -2.37, P = .02).

CONCLUSION

Target and transfer effects of VSOP training were identified, and links between VSOP training and two neural networks associated with aMCI were found. These findings highlight the potential of VSOP training to slow cognitive decline in individuals with aMCI. Further delineation of mechanisms underlying VSOP-induced plasticity is necessary to understand in which populations and under what conditions such training may be most effective.

An update on the advancements in the treatment of agitation in Alzheimer's disease

INTRODUCTION

Neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) are associated with significant negative outcomes for patients and their caregivers. Agitation, one of the most distressing NPS, lacks safe and effective long term interventions. Nonpharmacological interventions are suggested as first-line treatment, but aren't effective for every patient, resulting in pharmacological interventions for some patients, consisting of off-label use of antipsychotics, sedative/hypnotics, anxiolytics, acetylcholinesterase inhibitors, memantine, and antidepressants; where efficacy doesn't necessarily outweigh associated risks. Areas covered: Gains in understanding neurobiological mechanisms underlying agitation have fueled several recent clinical trials. This article updates our review published in 2014. Comprehensive literature search for published articles from January 2014 to December 2016 evaluating pharmacologic interventions for agitation in AD was done. A review of several clinical trials was completed: dextromethorphan/quinidine, scyllo-inositol, brexpiprazole, prazosin, cannabinoids, citalopram, escitalopram, pimavanserin, ITI-007, ORM-12741 show promise in treating agitation. Expert opinion: Neurobiological findings, innovative trials designs, statistical approaches, and preliminary paths for regulatory agency acceptance have re-ignited the area of pharmacological treatment of NPS. Though further research is needed to fully determine the safety, tolerability and efficacy of these treatments, the mission to find effective treatments for neuropsychiatric symptoms such as agitation in patients with dementia is well underway.

Principal components analysis of agitation outcomes in Alzheimer's disease

BACKGROUND

We developed a composite measure of agitation as a secondary outcome of change over time in the Citalopram for Agitation in Alzheimer's disease study (CitAD). CitAD demonstrated a positive effect of citalopram on agitation on the Neurobehavioral Rating Scale agitation subscale (NBRS-A). CitAD included additional agitation measures such as the Cohen-Mansfield Agitation Inventory and the Neuropsychiatric Inventory.

METHODS

We performed principal components analyses on change in individual item of these scales for the same, original CitAD subjects.

RESULTS

The first principal component accounted for 12.6% of the observed variance and was composed of items that appear to reflect agitation. The effect size for citalopram calculated using this component was 0.53 (95% CI 0.22-0.83) versus 0.32 for the NBRS-A (95% CI 0.01-0.62).

CONCLUSIONS

Results suggest that a composite measure of change in agitation might be more sensitive than change in a single primary agitation measure.

R- and S-citalopram concentrations have differential effects on neuropsychiatric scores in elders with dementia and agitation

AIMS

The aim was to determine the relationship between (R) and (S)-citalopram enantiomer exposure (AUC(0,24 h)) and therapeutic response in agitated individuals greater than 60 years old with Alzheimer's dementia (AD).

METHODS

Citalopram enantiomer exposures (AUC(0,24 h)) derived from an established population pharmacokinetic analysis were utilized to explore the relationship between (R)- and (S)-citalopram area under the curve (AUC(0,24 )) and Mini-Mental State Examination (MMSE), Neurobehavioural Rating Scale-Agitation Subscale (NBRS-A), modified Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (mADCS-CGIC) and Neuropsychiatric Inventory Agitation subscale (NPIA) scores. Time dependent changes in these scores (disease progression) were accounted for prior to exploring the exposure effect relationship for each enantiomer. These relationships were evaluated using a non-linear-mixed effects modelling approach as implemented in nonmem v7.3.

RESULTS

(S)-AUC(0,24 h) and (R)-AUC(0,24 h) each contributed to improvement in NBRS-A scores (k3(R) -0.502; k4(S) -0.712) as did time in treatment. However, increasing (R)-AUC(0,24 h) decreased the probability of patient response (maximum Δ -0.182%/AUC(0,24 h)) based on the CGIC while (S)-AUC(0,24 h) improved the probability of response (maximum Δ 0.112%/AUC(0,24 h)). (R)-AUC(0,24 h) was also associated with worsening in MMSE scores (-0.5 points).

CONCLUSIONS

Our results suggest that citalopram enantiomers contributed differentially to treatment outcomes. (R)-citalopram accounted for a greater proportion of the adverse consequences associated with racemic citalopram treatment in patients with AD including a decreased probability of treatment response as measured by the CGIC and a reduction in MMSE scores. The S-enantiomer was associated with increased probability of response based on the CGIC.

Effects of Citalopram on Neuropsychiatric Symptoms in Alzheimer's Dementia: Evidence From the CitAD Study

OBJECTIVE

Citalopram has been shown to improve agitation in patients with Alzheimer's disease. The authors evaluated whether other neuropsychiatric symptoms improve with citalopram treatment compared with placebo.

METHOD

In this planned secondary analysis of the Citalopram for Agitation in Alzheimer's Disease study, the authors evaluated the effect of citalopram on the 12 neuropsychiatric symptom domains assessed by the Neuropsychiatric Inventory (NPI). They compared caregiver-reported NPI scores at week 9 in patients receiving citalopram (30 mg/day) or placebo with regard to both the presence or absence of individual neuropsychiatric symptoms and individual domain scores (reflecting severity) in participants who had symptoms at week 9.

RESULTS

At week 9, participants treated with citalopram were significantly less likely to be reported as showing delusions (odds ratio=0.40), anxiety (odds ratio=0.43), and irritability/lability (odds ratio=0.38). A comparison of median scores of participants with symptoms present at week 9 showed significant differences favoring citalopram for hallucinations and favoring placebo for sleep/nighttime behavior disorders.

CONCLUSIONS

While dosage constraints must be considered because of citalopram's adverse effect profile, this agent's overall therapeutic effects in patients with Alzheimer's disease and agitation, in addition to efficacy for agitation/aggression, included reductions in the frequency of irritability, anxiety, and delusions; among patients who had these symptoms at week 9, they included a reduction in the severity of hallucinations but an increase in the severity of sleep/nighttime behavior disorders.

Heterogeneity of Treatment Response to Citalopram for Patients With Alzheimer's Disease With Aggression or Agitation: The CitAD Randomized Clinical Trial

OBJECTIVE

Pharmacological treatments for agitation and aggression in patients with Alzheimer's disease have shown limited efficacy. The authors assessed the heterogeneity of response to citalopram in the Citalopram for Agitation in Alzheimer Disease (CitAD) study to identify individuals who may be helped or harmed.

METHOD

In this double-blind parallel-group multicenter trial of 186 patients with Alzheimer's disease and clinically significant agitation, participants were randomly assigned to receive citalopram or placebo for 9 weeks, with the dosage titrated to 30 mg/day over the first 3 weeks. Five planned potential predictors of treatment outcome were assessed, along with six additional predictors. The authors then used a two-stage multivariate method to select the most likely predictors; grouped participants into 10 subgroups by their index scores; and estimated the citalopram treatment effect for each.

RESULTS

Five covariates were likely predictors, and treatment effect was heterogeneous across the subgroups. Patients for whom citalopram was more effective were more likely to be outpatients, have the least cognitive impairment, have moderate agitation, and be within the middle age range (76-82 years). Patients for whom placebo was more effective were more likely to be in long-term care, have more severe cognitive impairment, have more severe agitation, and be treated with lorazepam.

CONCLUSIONS

Considering several covariates together allowed the identification of responders. Those with moderate agitation and with lower levels of cognitive impairment were more likely to benefit from citalopram, and those with more severe agitation and greater cognitive impairment were at greater risk for adverse responses. Considering the dosages used and the association of citalopram with cardiac QT prolongation, use of this agent to treat agitation may be limited to a subgroup of people with dementia.

ERP C250 shows the elderly (cognitively normal, Alzheimer's disease) store more stimuli in short-term memory than Young Adults do

OBJECTIVE

To determine how aging and dementia affect the brain's initial storing of task-relevant and irrelevant information in short-term memory.

METHODS

We used brain Event-Related Potentials (ERPs) to measure short-term memory storage (ERP component C250) in 36 Young Adults, 36 Normal Elderly, and 36 early-stage AD subjects. Participants performed the Number-Letter task, a cognitive paradigm requiring memory storage of a first relevant stimulus to compare it with a second stimulus.

RESULTS

In Young Adults, C250 was more positive for the first task-relevant stimulus compared to all other stimuli. C250 in Normal Elderly and AD subjects was roughly the same to relevant and irrelevant stimuli in Intratrial Parts 1-3 but not 4. The AD group had lower C250 to relevant stimuli in part 1.

CONCLUSIONS

Both normal aging and dementia cause less differentiation of relevant from irrelevant information in initial storage. There was a large aging effect involving differences in the pattern of C250 responses of the Young Adult versus the Normal Elderly/AD groups. Also, a potential dementia effect was obtained.

SIGNIFICANCE

C250 is a candidate tool for measuring short-term memory performance on a biological level, as well as a potential marker for memory changes due to normal aging and dementia.

Citalopram for the Treatment of Agitation in Alzheimer Dementia: Genetic Influences

OBJECTIVE

To assess potential genetic influences on citalopram treatment efficacy for agitation in individuals with Alzheimer dementia (AD). Six functional genetic variants were studied in the following genes: serotonin receptor 2A (HTR2A-T102C), serotonin receptor 2C (HTR2C-Cys23Ser), serotonin transporter (5HTT-LPR), brain-derived neurotropic factor (BDNF-Val66Met), apolipoprotein E (ε2, ε3, ε4 variants), and cytochrome P450 (CYP2C19). Treatment response by genotype was measured by (1) the agitation domain of the Neurobehavioral Rating Scale, (2) the modified Alzheimer Disease Cooperative Study-Clinical Global Impression of Change scale (mADCS-CGIC), (3) the agitation domain of the Neuropsychiatric Inventory (NPI), and (4) the Cohen-Mansfield Agitation Inventory.

METHOD

We utilized data from the Citalopram for Agitation in Alzheimer's Disease (CitAD) database. CitAD was a 9-week randomized, double-blind, placebo-controlled multicenter clinical trial showing significant improvement in agitation and caregiver distress in patients treated with citalopram. Proportional odds logistic regression and mixed effects models were used to examine the above-mentioned outcome measures.

RESULTS

Significant interactions were noted on the NPI agitation domain for HTR2A (likelihood ratio [LR] = 6.19, df = 2, P = .04) and the mADCS-CGIC for HTR2C (LR = 4.33, df = 2, P = .02) over 9 weeks.

DISCUSSION

Treatment outcomes in CitAD showed modest, although statistically significant, influence of genetic variation at HTR2A and HTR2C loci. Future studies should continue to examine the interaction of known genetic variants with antidepressant treatment in patients with AD having agitation.

Trajectories of Neuropsychiatric Symptoms and Cognitive Decline in Mild Cognitive Impairment

OBJECTIVE

To characterize the course of neuropsychiatric symptoms (NPS) in adults with mild cognitive impairment (MCI), and to examine baseline individual-level predictors and associated cognitive and functional outcomes.

DESIGN

A 2-year prospective cohort study.

SETTING

Multicenter clinical settings.

PARTICIPANTS

Five hundred sixty individuals with MCI at baseline.

MEASUREMENTS

NPS severity (measured using Neuropsychiatric Inventory Questionnaire) and cognitive and functional outcomes were assessed at baseline and every 6 months thereafter. Potential individual-level predictors were collected at baseline.

RESULTS

Three latent classes of NPS courses were identified using growth mixture modeling: a stable class in which a low NPS burden remained relatively unchanged over time (N = 503, 89.8%); a worsened class in which an initially moderate NPS burden increased (N = 39, 7.0%); and an improved class in which an initially high NPS burden decreased (N = 18, 3.2%). There were no associations between class membership and baseline individual characteristics. Members of the worsened class were 1.74 times more likely to be diagnosed with incident Alzheimer disease (AD) than members of the stable class (95% confidence interval: 1.07-2.84). The worsened class also showed significantly more rapid declines in cognitive and functional outcomes than the stable class. Class membership did not predict rate of brain atrophy.

CONCLUSIONS

Patients with MCI may experience different trajectories of NPS over time. Patients with worsening NPS may be at greater risk of developing AD and severe cognitive and functional impairment.

Change in agitation in Alzheimer's disease in the placebo arm of a nine-week controlled trial

BACKGROUND

Placebo responses raise significant challenges for the design of clinical trials. We report changes in agitation outcomes in the placebo arm of a recent trial of citalopram for agitation in Alzheimer's disease (CitAD).

METHODS

In the CitAD study, all participants and caregivers received a psychosocial intervention and 92 were assigned to placebo for nine weeks. Outcomes included Neurobehavioral Rating Scale agitation subscale (NBRS-A), modified AD Cooperative Study-Clinical Global Impression of Change (CGIC), Cohen-Mansfield Agitation Inventory (CMAI), the Neuropsychiatric Inventory (NPI) Agitation/Aggression domain (NPI A/A) and Total (NPI-Total) and ADLs. Continuous outcomes were analyzed with mixed-effects modeling and dichotomous outcomes with logistic regression.

RESULTS

Agitation outcomes improved over nine weeks: NBRS-A mean (SD) decreased from 7.8 (3.0) at baseline to 5.4 (3.2), CMAI from 28.7 (6.7) to 26.7 (7.4), NPI A/A from 8.0 (2.4) to 4.9 (3.8), and NPI-Total from 37.3 (17.7) to 28.4 (22.1). The proportion of CGI-C agitation responders ranged from 21 to 29% and was significantly different from zero. MMSE improved from 14.4 (6.9) to 15.7 (7.2) and ADLs similarly improved. Most of the improvement was observed by three weeks and was sustained through nine weeks. The major predictor of improvement in each agitation measure was a higher baseline score in that measure.

CONCLUSIONS

We observed significant placebo response which may be due to regression to the mean, response to a psychosocial intervention, natural course of symptoms, or nonspecific benefits of participation in a trial.

A population pharmacokinetic model for R- and S-citalopram and desmethylcitalopram in Alzheimer's disease patients with agitation

The citalopram for Alzheimer’s disease trial evaluated citalopram for the management for agitation in Alzheimer’s disease patients. Sparse data was available from this elderly patient population. A nonlinear mixed effects population pharmacokinetic modeling approach was used to describe the pharmacokinetics of R- and S-citalopram and their primary metabolite (desmethylcitalopram). A structural model with 4 compartments (one compartment/compound) with linear oral absorption and elimination described the data adequately. Overall, the model showed that clearance of the R-enantiomer was slower than the clearance of the S-enantiomer. Without accounting for any patient-specific covariates, the population estimate of the metabolic clearance of citalopram was 8.6 (R-citalopram) and 14 L/h (S-citalopram). The population estimate of the clearance of desmethylcitalopram was 23.8 (R-Dcit) and 38.5 L/h (S-Dcit). Several patient-specific covariates were found to have a significant effect on the pharmacokinetics of R,S-citalopram and desmethylcitalopram. A significant difference in the metabolic clearance of R-citalopram between males and females (13 vs 9.05 L/h) was identified in this analysis. Both R- and S-citalopram metabolic clearance decreased with age. Additionally, consistent with literature reports S-citalopram metabolic clearance increased with increasing body weight and was significantly influenced by CYPC19 genotype, with a difference of 5.8 L/h between extensive/rapid and intermediate/poor metabolizers. R,S-desmethylcitalopram clearance increased with increasing body weight. This model may allow for the opportunity to delineate the effect of R- and S-citalopram on pharmacodynamics outcomes related to the management of agitation in Alzheimer’s disease.

Time to Response to Citalopram Treatment for Agitation in Alzheimer Disease

OBJECTIVE

Agitation is a common and significant problem in Alzheimer disease (AD). In the recent Citalopram for Agitation in Alzheimer's Disease (CitAD) study, citalopram was efficacious for the treatment of AD agitation. Here we examined the time course and predictors of response to treatment.

METHODS

Response in CitAD was defined as a modified Alzheimer Disease Cooperative Study Clinical Global Impression of Change (CGIC) score of 1 or 2 or a Neurobehavioral Rating Scale agitation subscale (NBRS-A) score reduction ≥ 50% from baseline. "Stable early response" was defined as meeting the aforementioned criteria at both weeks 3 and 9, "late response" was response at week 9 but not at week 3, and "unstable response" was response at week 3 but not at week 9.

RESULTS

In the primary analyses, citalopram was superior to placebo on both the CGIC and the NBRS-A response measures. Little between-group differences were found in response rates in the first 3 weeks of the study (21% versus 19% on the CGIC). Citalopram patients were more likely than placebo patients to be a late responder (18% versus 8% on CGIC, Fisher's exact p = 0.09; 31% versus 15% on NBRS-A, Fisher's exact p = 0.02). Approximately half of citalopram responders (45%-56%) at end of study achieved response later in the study compared with 30%-44% of placebo responders.

CONCLUSION

Treatment with citalopram for agitation in AD needs to be at least 9 weeks in duration to allow sufficient time for full response. Study duration is an important factor to consider in the design of clinical trials for agitation in AD.

Effect of Dextromethorphan-Quinidine on Agitation in Patients With Alzheimer Disease Dementia: A Randomized Clinical Trial

IMPORTANCE

Agitation is common among patients with Alzheimer disease; safe, effective treatments are lacking.

OBJECTIVE

To assess the efficacy, safety, and tolerability of dextromethorphan hydrobromide-quinidine sulfate for Alzheimer disease-related agitation.

DESIGN, SETTING, AND PARTICIPANTS

Phase 2 randomized, multicenter, double-blind, placebo-controlled trial using a sequential parallel comparison design with 2 consecutive 5-week treatment stages conducted August 2012-August 2014. Patients with probable Alzheimer disease, clinically significant agitation (Clinical Global Impressions-Severity agitation score ≥4), and a Mini-Mental State Examination score of 8 to 28 participated at 42 US study sites. Stable dosages of antidepressants, antipsychotics, hypnotics, and antidementia medications were allowed.

INTERVENTIONS

In stage 1, 220 patients were randomized in a 3:4 ratio to receive dextromethorphan-quinidine (n = 93) or placebo (n = 127). In stage 2, patients receiving dextromethorphan-quinidine continued; those receiving placebo were stratified by response and rerandomized in a 1:1 ratio to dextromethorphan-quinidine (n = 59) or placebo (n = 60).

MAIN OUTCOMES AND MEASURES

The primary end point was change from baseline on the Neuropsychiatric Inventory (NPI) Agitation/Aggression domain (scale range, 0 [absence of symptoms] to 12 [symptoms occur daily and with marked severity]).

RESULTS

A total of 194 patients (88.2%) completed the study. With the sequential parallel comparison design, 152 patients received dextromethorphan-quinidine and 127 received placebo during the study. Analysis combining stages 1 (all patients) and 2 (rerandomized placebo nonresponders) showed significantly reduced NPI Agitation/Aggression scores for dextromethorphan-quinidine vs placebo (ordinary least squares z statistic, -3.95; P < .001). In stage 1, mean NPI Agitation/Aggression scores were reduced from 7.1 to 3.8 with dextromethorphan-quinidine and from 7.0 to 5.3 with placebo. Between-group treatment differences were significant in stage 1 (least squares mean, -1.5; 95% CI, -2.3 to -0.7; P<.001). In stage 2, NPI Agitation/Aggression scores were reduced from 5.8 to 3.8 with dextromethorphan-quinidine and from 6.7 to 5.8 with placebo. Between-group treatment differences were also significant in stage 2 (least squares mean, -1.6; 95% CI, -2.9 to -0.3; P=.02). Adverse events included falls (8.6% for dextromethorphan-quinidine vs 3.9% for placebo), diarrhea (5.9% vs 3.1% respectively), and urinary tract infection (5.3% vs 3.9% respectively). Serious adverse events occurred in 7.9% with dextromethorphan-quinidine vs 4.7% with placebo. Dextromethorphan-quinidine was not associated with cognitive impairment, sedation, or clinically significant QTc prolongation.

CONCLUSIONS AND RELEVANCE

In this preliminary 10-week phase 2 randomized clinical trial of patients with probable Alzheimer disease, combination dextromethorphan-quinidine demonstrated clinically relevant efficacy for agitation and was generally well tolerated.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01584440.

Role of citalopram in the treatment of agitation in Alzheimer's disease

Neuropsychiatric symptoms (NPS) are common among individuals with Alzheimer's disease (AD), associated with excess morbidity and mortality, greater healthcare use, earlier institutionalization, and caregiver burden. Agitation presents as emotional distress, excessive psychomotor activity, aggressive behaviors, disruptive irritability and dishibition. There is an unmet need to find pharmacologic treatment for agitation in patients with AD that can be safely and effectively used as a concurrent treatment alongside psychosocial interventions. A recent, multicenter, randomized, placebo-controlled trial explored the efficacy of a 30-mg daily dose of citalopram for agitation in patients with AD and showed a significant decrease in agitation for citalopram compared with placebo. Both QTc prolongation and cognitive worsening, as measured by the Mini Mental State Examination, were observed in the citalopram group and present a concern to clinicians. Citalopram at a 20-mg daily dose should be considered as a possible first-line treatment in addition to psychosocial intervention.