Recommendations for the Nonpharmacological Treatment of Apathy in Brain Disorders

Progress in Pharmacologic Management of Neuropsychiatric Syndromes in Neurodegenerative Disorders: A Review

Importance

Neuropsychiatric syndromes (NPSs) are common in neurodegenerative disorders (NDDs); compromise the quality of life of patients and their care partners; and are associated with faster disease progression, earlier need for nursing home care, and poorer quality of life. Advances in translational pharmacology, clinical trial design and conduct, and understanding of the pathobiology of NDDs are bringing new therapies to clinical care.

Observations

Consensus definitions have evolved for psychosis, agitation, apathy, depression, and disinhibition in NDDs. Psychosocial interventions may reduce mild behavioral symptoms in patients with NDD, and pharmacotherapy is available for NPSs in NDDs. Brexpiprazole is approved for treatment of agitation associated with Alzheimer disease dementia, and pimavanserin is approved for treatment of delusions and hallucinations associated with psychosis of Parkinson disease. Trials are being conducted across several of the NDDs, and a variety of mechanisms of action are being assessed for their effect on NPSs.

Conclusions and Relevance

Detection and characterization of NPSs in patients with NDDs is the foundation for excellent care. New definitions for NPSs in NDDs may inform choices regarding clinical trial populations and translate into clinical practice. Psychosocial and pharmacologic therapies may reduce behavioral symptoms and improve quality of life for patients and caregivers. Approved agents may establish regulatory precedents, demonstrate successful trial strategies, and provide the foundation for further advances in treatment development.

Guideline Recommendations on Behavioral and Psychological Symptoms of Dementia: A Systematic Review

OBJECTIVE

To synthesize recommendations on assessing and managing behavioral and psychological symptoms of dementia (BPSDs) in existing clinical practice guidelines on dementia care to learn from and adapt recommendations to a Canadian context and language for describing BPSDs.

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

Moderate to high-quality clinical practice guidelines on dementia care that made 1 or more recommendations on BPSD assessment or management.

METHODS

We searched MEDLINE, Embase, JBI EBM, PsycINFO, AgeLine, and gray literature for clinical practice guidelines on dementia care making recommendations on BPSD, published between January 1, 2011, and October 13, 2022. Two independent reviewers conducted study screening and data abstraction. Four independent reviewers completed quality appraisal using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool; included guidelines had a mean overall AGREE II score ≥4.

RESULTS

Our systematic review identified 23 moderate to high-quality clinical practice guidelines (264 recommendations). The mean overall quality score on the AGREE II tool ranged from 4 to 6.5. Recommendations were clearly presented (mean clarity of presentation score 73.5%), but guideline applicability was not consistently addressed (mean applicability score 39.3%). BPSD was the most prevalent term describing neuropsychiatric symptoms (number of guidelines [n] = 14). People with lived experience contributed to 6 guidelines (26.1%). Ten guidelines (43.5%) described 1 or more health equity considerations. Guidelines made recommendations for assessing and managing agitation (n = 12), aggression (n = 10), psychosis (n = 11), depression (n = 9), anxiety (n = 5), apathy (n = 6), inappropriate sexual behavior (n = 3), nighttime behavior (n = 5), and eating disturbances (n = 3). There was substantial variability in recommendation statements, evidence quality assigned to each statement, and strength of recommendations.

CONCLUSIONS AND IMPLICATIONS

There are several moderate to high-quality clinical practice guidelines making recommendations on BPSD assessment and management, but variability in recommendation statements across guidelines and insufficient consideration of guideline applicability may hamper guideline dissemination and implementation in clinical practice.

Treatment of Apathy in Parkinson's Disease and Implications for Underlying Pathophysiology

Apathy is a prevalent and highly debilitating non-motor symptom of Parkinson's disease (PD) that is often overlooked in clinical practice due to its subtle nature. This review aims to provide a comprehensive overview of the current evidence for the treatment of apathy in PD, highlighting recent advancements and emerging therapeutic avenues. In this review, we analyse a diverse array of treatment strategies for apathy in PD, including pharmacological interventions, non-pharmacological approaches, and emerging neuromodulation techniques. We evaluate the efficacy, safety, and limitations of established pharmacotherapies, such as dopaminergic agents, antidepressants, and cognitive enhancers. Additionally, we examine the promising role of non-pharmacological interventions, encompassing psychotherapies and behavioural interventions, in ameliorating apathetic symptoms. Furthermore, this review explores the effects of neuromodulation techniques on apathy, including the modulation of apathy via deep brain stimulation and emerging data on the potential influence of transcranial magnetic stimulation (TMS) on apathy in PD. Ultimately, a deeper understanding of effective treatment strategies for apathy has the potential to significantly improve the quality of life and overall well-being of individuals living with PD.

Apathy and Motivation: Biological Basis and Drug Treatment

Apathy is a disabling syndrome associated with poor functional outcomes that is common across a broad range of neurological and psychiatric conditions. Currently, there are no established therapies specifically for the condition, and safe and effective treatments are urgently needed. Advances in the understanding of motivation and goal-directed behavior in humans and animals have shed light on the cognitive and neurobiological mechanisms contributing to apathy, providing an important foundation for the development of new treatments. Here, we review the cognitive components, neural circuitry, and pharmacology of apathy and motivation, highlighting converging evidence of shared transdiagnostic mechanisms. Though no pharmacological treatments have yet been licensed, we summarize trials of existing and novel compounds to date, identifying several promising candidates for clinical use and avenues of future drug development.

Repetitive transcranial magnetic stimulation for apathy in patients with neurodegenerative conditions, cognitive impairment, stroke, and traumatic brain injury: a systematic review

Background

We aimed to determine the effects and tolerability of repetitive transcranial magnetic stimulation (rTMS) on apathy in patients with neurodegenerative conditions, mild cognitive impairment (MCI), stroke, and traumatic brain injury (TBI) via systematic review.

Methods

We conducted a systematic search in major electronic health databases, including PubMed, Scopus, and PsycINFO, covering the period from inception to June 2023. Comparative clinical trials and cohort studies, and studies with before-after designs were considered for inclusion. We used the Cochrane Risk of Bias and the National Institutes of Health (NIH) tools to assess methodological quality.

Results

Out of 258 records identified, 14 studies met our eligibility criteria (11 randomized controlled trials (RCT) and 3 studies utilized before-and-after designs) with a total of 418 patients (overall female-to-male ratio 1:1.17) included in the review. The overall methodological quality of the included studies was assessed to be fair to good. The stimulation parameters used varied considerably across the studies. The summary findings of our review indicate the following observations on the effects of rTMS on apathy: (1) the results of all included studies in Alzheimer's disease investigating the effects of rTMS on apathy have consistently shown a positive impact on apathy; (2) the majority of studies conducted in Parkinson's disease have not found statistically significant results; (3) a single study (RCT) on patients with primary progressive aphasia demonstrated significant beneficial effects of rTMS on apathy; (4) the trials conducted on individuals with MCI yielded varying conclusions; (5) one study (RCT) in chronic stroke suggested that rTMS might have the potential to improve apathy; (6) one study conducted on individuals with mild TBI did not find a significant favorable association on apathy; and (7) the use of different rTMS protocols on the populations described is generally safe.

Conclusion

The feasibility of utilizing rTMS as a treatment for apathy has been suggested in this review. Overall, limited evidence suggests that rTMS intervention may have the potential to modify apathy among patients with AD, PPA, MCI and chronic stroke, but less so in PD and mild TBI. These findings require confirmation by larger, well-designed clinical trials.

Validation study of the apathy motivation index in French adults

Objective

Apathy is present in many brain disorders, but it is also prevalent to varying degrees in healthy people. While many tools have been developed to assess levels of apathy in pathology, no standardized measure of apathy in healthy people exists.

Method

Therefore, this study aimed to validate the French version of the Apathy Motivation Index (f-AMI). The results of 729 participants were analyzed using an exploratory factorial analysis.

Results

Preliminary analyses suggested that the three domains of apathy extracted in the original AMI scale-behavioral activation (BA), social motivation (SM), and emotional sensitivity (ES)-could be found also in the f-AMI. A further exploratory analysis showed that a higher number of factors could be extracted, particularly for women. Specifically, both social and emotional factors could be divided into two sub-factors: (1) social motivation toward strangers or toward an acquaintance and (2) self-directed emotional sensitivity directed toward others. Regarding construct validity, the scores of f-AMI were correlated with the French Dimensional Apathy Scale results. Concerning the divergent validity, emotional sensitivity in apathy is different from depression, anhedonia, and fatigue levels.

Conclusion

These results suggest that the f-AMI can be used to assess levels of apathy in healthy adults.

Reduced Sensitivity to Background Reward Underlies Apathy After Traumatic Brain Injury: Insights From an Ecological Foraging Framework

BACKGROUND

Altered reward processing is increasingly recognised as a crucial mechanism underpinning apathy in many brain disorders. However despite its clinical relevance, little is known about the mechanisms of apathy following moderate-to-severe traumatic brain injury (TBI). In real-life situations, reward representations encompass both foreground (gains from current activity) and background (potential gains from the broader environment) elements. This latter variable provides a crucial set-point for switching behaviour in many naturalistic settings. We hypothesised apathy post-TBI would be associated with disrupted background reward sensitivity.

METHODS

We administered a computer-based foraging task to 45 people with moderate-to-severe TBI (20 with apathy, 39 males) and 37 matched controls. Participants decided when to leave locations (patches) where foreground reward rates depleted at differing rates, to pursue greater rewards from other patches in the environment, which had either a high or low background reward rate. Primary analysis was performed using linear mixed effects models, with patch leaving time the dependent variable.

RESULTS

Findings showed a significant interaction between apathy and background reward sensitivity, driven by apathetic TBI participants not altering patch-leaving decisions as environmental reward rate changed. In contrast, although TBI was associated with reduced sensitivity to changing foreground rewards, this did not vary as a function of apathy.

CONCLUSIONS

These results provide the first evidence directly linking disrupted background reward processing to apathy in any brain disorder. They identify a novel mechanism for apathy following moderate-to-severe TBI, and point towards novel interventions to improve this debilitating complication of head injury.

Apathy Among Persons Living With HIV Is Associated With Lower Self-efficacy for Health Care Provider Interactions

ABSTRACT

Apathy is common in persons with HIV (PWH) and has been associated with a variety of health outcomes. We examined the association between apathy and self-efficacy for health care provider interactions in 142 PWH. A composite score comprised of the apathy subscale of the Frontal Systems Behavioral Scale and the vigor-activation scale of the Profile of Mood States was used to measure apathy. Self-efficacy for health care provider interactions was measured using the Beliefs Related to Medication Adherence - Dealing with Health Professional subscale. Higher levels of apathy were associated with lower self-efficacy for health care provider interactions at a medium effect size, independent of mood disorders, health literacy, and neurocognition. Findings suggest that apathy plays a unique role in self-efficacy for health care provider interactions and support the importance of assessment and management of apathy to maximize health outcomes among PWH.

Apathy in Alzheimer's disease: A neurocircuitry based perspective

In addition to memory deficits and other cognitive disturbances, patients with Alzheimer's disease (AD) experience neuropsychiatric symptoms, notably apathy, which is a state of impaired motivation observed by deficits in goal directed behavior. Apathy is a multifaceted neuropsychiatric condition and appears to be a prognostic indicator, correlating with the progression of AD. Strikingly, recent studies point out that the neurodegenerative pathology of AD may drive apathy independent of cognitive decline. These studies also highlight that neuropsychiatric symptoms, in particular apathy, might manifest early in AD. Here, we review the current understanding of the neurobiological underpinnings of apathy as a neuropsychiatric symptom of AD. Specifically, we highlight the neural circuits and brain regions recognized to be correlated with the apathetic symptomatology. We also discuss the current evidence that supports the notion that apathy and cognitive deficits may develop as independent but concurrent phenomena driven by AD pathology, suggesting its efficacy as an additional outcome measure in Alzheimer's disease clinical trials. The current and prospective therapeutic interventions for apathy in AD from a neurocircuitry based perspective are also reviewed.

Strengths and Weaknesses of the Vascular Apathy Hypothesis: A Narrative Review

The vascular apathy hypothesis states that cerebral small vessel disease (CSVD) can cause apathy, even when no other symptoms of CSVD are present. In order to examine this hypothesis, the objectives of this narrative review are to evaluate the evidence for a pathophysiological mechanism linking CSVD to apathy and to examine whether CSVD can be a sole cause of apathy. The nature of the CSVD-apathy relationship was evaluated using the Bradford Hill criteria as a method for research on the distinction between association and causation. Pathological, neuroimaging, and behavioral studies show that CSVD can cause lesions in the reward network, which causes an apathy syndrome. Studies in healthy older individuals, stroke patients and cognitively impaired persons consistently show an association between CSVD markers and apathy, although studies in older persons suffering from depression are inconclusive. A biological gradient is confirmed, as well as a temporal relationship, although the evidence for the latter is still weak. The specificity of this causal relationship is low given there often are other contributing factors in CSVD patients with apathy, particularly depression and cognitive deterioration. Differentiating between vascular apathy and other apathy syndromes on the basis of clinical features is not yet possible, while in-depth knowledge about differences in the prognosis and efficacy of treatment options for apathy caused by CSVD and other apathy syndromes is lacking. Since we cannot differentiate between etiologically different apathy syndromes as yet, it is premature to use the term vascular apathy which would suggest a distinct clinical apathy syndrome.

Behavioural disinhibition in frontotemporal dementia investigated within an ecological framework

Disinhibition is a core symptom in behavioural variant frontotemporal dementia (bvFTD) particularly affecting the daily lives of both patients and caregivers. Yet, characterisation of inhibition disorders is still unclear and management options of these disorders are limited. Questionnaires currently used to investigate behavioural disinhibition do not differentiate between several subtypes of disinhibition, encompass observation biases and lack of ecological validity. In the present work, we explored disinhibition in an original semi-ecological situation, by distinguishing three categories of disinhibition: compulsivity, impulsivity and social disinhibition. First, we measured prevalence and frequency of these disorders in 23 bvFTD patients and 24 healthy controls (HC) in order to identify the phenotypical heterogeneity of disinhibition. Then, we examined the relationships between these metrics, the neuropsychological scores and the behavioural states to propose a more comprehensive view of these neuropsychiatric manifestations. Finally, we studied the context of occurrence of these disorders by investigating environmental factors potentially promoting or reducing them. As expected, we found that patients were more compulsive, impulsive and socially disinhibited than HC. We found that 48% of patients presented compulsivity (e.g., repetitive actions), 48% impulsivity (e.g., oral production) and 100% of the patients group showed social disinhibition (e.g., disregards for rules or investigator). Compulsivity was negatively related with emotions recognition. BvFTD patients were less active if not encouraged in an activity, and their social disinhibition decreased as activity increased. Finally, impulsivity and social disinhibition decreased when patients were asked to focus on a task. Summarising, this study underlines the importance to differentiate subtypes of disinhibition as well as the setting in which they are exhibited, and points to stimulating area for non-pharmacological management.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Apathy in patients with Alzheimer's disease is a cost-driving factor

BACKGROUND

Apathy is the most frequent neuropsychiatric symptom in patients with dementia of the Alzheimer's type (DAT). We analyzed the influence of apathy on the resource use of DAT patients and their caregivers.

METHODS

Included were baseline data of 107 DAT patients from a randomized clinical trial on apathy treatment. The Resource Utilization in Dementia (RUD) instrument assessed costs over a 1-month period prior to baseline. Cost predictors were determined via a least absolute shrinkage and selection operator (LASSO).

RESULTS

On average, total monthly costs were €3070, of which €2711 accounted for caregivers' and €359 for patients' costs. An increase of one point in the Apathy Evaluation Scale resulted in a 4.1% increase in total costs.

DISCUSSION

Apathy is a significant cost driving factor for total costs in mild to moderate DAT. Effective treatment of apathy might be associated with reduced overall costs in DAT.

Cutoff scores for the "Interest game", an application for the assessment of diminished interest in neurocognitive disorders

Diminished interest is a core feature of apathy that shows high prevalence in people with Mild and Major Neurocognitive disorders (NCD). In the clinical setting, apathy is mainly assessed using clinical scales and questionnaires, but new technologies are starting to be employed to complement classical instruments. Here, we explored the performance of the "Interest game," a ludic application that assesses personal interests, in discriminating between persons with and without diminished interest based on the Apathy Diagnostic Criteria. Two hundred and twenty-seven elderly participants (56 healthy controls, 118 persons with mild-NCD, and 53 with major-NCD) completed the Interest game and were assessed by clinicians concerning the presence and the severity of apathy. Results showed that the application scores varied with the presence of apathy, the type of disorder, and the education level. Cutoff scores calculated for persons with Mild-NCD resulted in a sensitivity of 0.68 and a specificity of 0.65 for the main score index, suggesting the interest of employing this application in the clinical setting to complement the classical assessment.

Semiology and determinants of apathy across neurodegenerative motor disorders: A comparison between amyotrophic lateral sclerosis, Parkinson’s and Huntington’s disease

Background

The semiology and determinants of apathy are largely unknown across amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), and Huntington’s disease (HD), due to both motor and non-motor confounders. This study thus aimed at (1) profiling apathy in ALS, PD, and HD and (2) exploring its clinical determinants.

Materials

Consecutive ALS (N = 99), PD (N = 73), and HD (N = 25) patients underwent a motor-free assessment of apathy (Dimensional Apathy Scale, DAS), global cognition, anxiety and depression. Function was assessed through disease-specific scales. The DAS was also completed by N = 101 healthy controls (HCs). Between-group comparisons on DAS scores were implemented by covarying for all applicable confounders. Predictive models on DAS scores were built through multiple, stepwise regressions.

Results

Parkinson’s disease and HD, but not ALS, patients were more apathetic than HCs—with HD patients also selectively showing lower initiation and poorer goal-directed planning than HCs. Higher apathetic features were detected in PD and HD as compared to ALS. Education was a protective factor against apathy in ALS. Anxiety was a risk factor for global apathy in ALS, HD, and to a lesser extent, in PD, whereas, protective only toward affective disintegration in PD and ALS. Cognitive inefficiency was a risk factor toward apathy in both PD and ALS. Depression was a risk factor for executive-related apathy in PD.

Discussion

This study provides unprecedented insights into the heterogeneous semiology and determinants of apathy across ALS, PD, and HD via the DAS, in turn informing clinical practice and research.

Apathy in Parkinson’s Disease: Defining the Park Apathy Subtype

Apathy is a neurobehavioural symptom affecting Parkinson’s disease patients of all disease stages. Apathy seems to be associated with a specific underlying non-motor disease subtype and reflects dysfunction of separate neural networks with distinct neurotransmitter systems. Due to the complicated neuropsychiatric aetiology of apathy, clinical assessment of this invalidating non-motor symptom remains challenging. We aim to summarize the current findings on apathy in Parkinson’s disease and highlight knowledge gaps. We will discuss the prevalence rates across the different disease stages and suggest screening tools for clinically relevant apathetic symptoms. We will approach the fundamental knowledge on the neural networks implicated in apathy in a practical manner and formulate recommendations on patient-tailored treatment. We will discuss the Park apathy phenotype in detail, shedding light on different clinical manifestations and implications for prognosis. With this review, we strive to distil the vast available theoretical knowledge into a clinical and patient-oriented perspective.

Risk factors for apathy in Alzheimer's disease: A systematic review of longitudinal evidence

BACKGROUND

Apathy is frequent and persistent in Alzheimer's disease (AD), associated with poor prognosis and carer distress; yet our knowledge of risk factors remains limited.

AIMS

To identify risk factors associated with apathy incidence and progression in AD over time.

METHODS

We systematically reviewed evidence based on longitudinal studies assessing risk factors for apathy in AD up to June 2021. Two authors independently assessed article eligibility and rated quality.

RESULTS

13,280 articles were screened, of which 13 met inclusion criteria. Studies had a mean follow-up of 2.7 years reporting on a total of 2012 participants. Most findings were based on single studies of moderate quality evidence. Risk factors increasing apathy onset were: being a carrier of the T allele of the PRND gene polymorphism, and having high levels of the IL-6 and TNFα cytokines at baseline. Risk factors for apathy worsening were: reduced inferior-temporal cortical thickness, taking antidepressants, being an ApoE ε4 carrier, living longer with AD, lower cognitive test scores, higher baseline apathy, premorbid personality traits (lower agreeableness, higher neuroticism), and higher midlife motivational abilities.

CONCLUSIONS

Although results are limited by the small number of studies, this review identified specific genetic, neurobiological, AD specific, and dispositional factors that may increase risk of apathy onset and worsening in AD.

The stability of multidimensional subclinical apathy during a pandemic and its relations to psycho-behavioral factors

Apathy is a clinical symptom prevalent in many neuropsychiatric pathologies. Subclinical apathy is found in 35% of the general population. Despite high prevalence and negative consequences, underlying mechanisms are poorly understood, perhaps because the concept of apathy is one-dimensional. The current investigation aims to address the incidence of multidimensional apathetic trait in three distinct forms in a student population, to specify its determinants and to evaluate its stability during a global pandemic. Two online surveys, conducted 1 year apart on two separate cohorts of university students, with qualitative measures and validated scales. The final analysis included, respectively, 2789 and 1678 students. The three forms of apathetic trait were present, with the same debilitating consequences as apathetic symptom but independent determinants. Executive apathy was predicted by depressive symptoms, emotional apathy by motivational deficit and initiative apathy comprised a mixed executive-emotional form and a pure deficit of action initiation. The three forms of subclinical apathy remained similar in the context of increased depressive symptoms due to a global pandemic. This study confirmed the presence and independence of three forms of subclinical apathy in healthy students, which remained similar even in the light of increased depressive scores. These results shed light on cognitive and neuronal mechanisms underlying multidimensional apathy, allowing new, targeted treatments.

Apathy as a Treatment Target in Alzheimer's Disease: Implications for Clinical Trials

Apathy is one of the most prevalent, stable and persistent neuropsychiatric symptom across the neurocognitive disorders spectrum. Recent advances in understanding of phenomenology, neurobiology and intervention trials highlight apathy as an important target for clinical intervention. We conducted a comprehensive review and critical evaluation of recent advances to determine the evidence-based suggestions for future trial designs. This review focused on 4 key areas: 1) pre-dementia states; 2) assessment; 3) mechanisms/biomarkers and 4) treatment/intervention efficacy. Considerable progress has been made in understanding apathy as a treatment target and appreciating pharmacological and non-pharmacological apathy treatment interventions. Areas requiring greater investigation include: diagnostic procedures, symptom measurement, understanding the biological mechanisms/biomarkers of apathy, and a well-formed approach to the development of treatment strategies. A better understanding of the subdomains and biological mechanisms of apathy will advance apathy as a treatment target for clinical trials.

Factors Associated with Apathy in Alzheimer’s Disease: A Cross-Sectional Analysis of the Texas Alzheimer’s Research and Care Consortium (TARCC) Study

Background: Apathy is among the most frequent neuropsychiatric syndromes in Alzheimer’s disease (AD). Objective: To determine the prevalence of apathy and the associated clinical and laboratorial parameters (focus on inflammatory biomarkers) in patients with dementia enrolled at the Texas Alzheimer’s Research and Care Consortium (TARCC) study. Methods: This is a cross-sectional analysis of TARCC baseline. Participants were evaluated through different clinical tools, including the Mini-Mental State Examination (MMSE) and the Lawton-Brody Instrumental Activities of Daily Life (IADL)/Physical Self-Maintenance Scale (PSMS). Apathy was defined by a positive response to the respective item in the Neuropsychiatric Inventory–Questionnaire applied to caregivers. Serum levels of 16 biomarkers were determined by HumanMap multiplex immunoassay. Comparisons between apathy versus non-apathy groups were carried out with non-parametric tests. Logistic regression and the least absolute shrinkage and selection operator (LASSO) were used to separately model apathy as a function of each biomarker, adjusted for the potential confounders. Results: From 1,319 patients with AD (M/F: 579/740, mean age ± SD: 75.3 ± 8.4), 373 (28.3%) exhibited apathy. When categorized according to the presence of apathy, the groups had significant differences in sex, diabetes diagnosis, and tobacco use. The apathy group also had worse cognitive performance and daily functioning than the non-apathy group as assessed, respectively, by MMSE and IADL/PSMS. Higher levels of interleukin-6, interleukin-10, and leptin were associated with higher odds of apathy. Conclusion: Apathy is associated with cognitive and functional status in AD. The association between apathy and peripheral inflammatory mediators deserves further investigation.

Revisiting Apathy in Alzheimer's Disease: From Conceptualization to Therapeutic Approaches

Apathy is a neurobehavioral syndrome characterized by impaired motivation for goal-directed behaviors and cognitive activity, alongside blunted affect. Apathy is a common neuropsychiatric syndrome in Alzheimer's disease (AD), with a 5-year prevalence over 70%. Apathy also serves as a prognostic indicator, correlating with the progression of AD. Despite advances in its conceptualization and understanding of its neural basis, there is very limited empirical evidence to support the available strategies for the treatment of apathy in AD. Given its complex pathophysiology, including distinct substrates for different apathy dimensions (affective, cognitive, and behavioral), it is unlikely that a single pharmacological or nonpharmacological strategy will be effective for all cases of apathy in AD. High-quality evidence research is needed to better understand the role of specific strategies aiming at a personalized approach.

ECOCAPTURE@HOME: Protocol for the Remote Assessment of Apathy and Its Everyday-Life Consequences

Apathy, a common neuropsychiatric symptom associated with dementia, has a strong impact on patients’ and caregivers’ quality of life. However, it is still poorly understood and hard to define. The main objective of the ECOCAPTURE programme is to define a behavioural signature of apathy using an ecological approach. Within this program, ECOCAPTURE@HOME is an observational study which aims to validate a method based on new technologies for the remote monitoring of apathy in real life. For this study, we plan to recruit 60 couples: 20 patient-caregiver dyads in which patients suffer from behavioral variant Fronto-Temporal Dementia, 20 patient-caregiver dyads in which patients suffer from Alzheimer Disease and 20 healthy control couples. These dyads will be followed for 28 consecutive days via multi-sensor bracelets collecting passive data (acceleration, electrodermal activity, blood volume pulse). Active data will also be collected by questionnaires on a smartphone application. Using a pool of metrics extracted from these passive and active data, we will validate a measurement model for three behavioural markers of apathy (i.e., daytime activity, quality of sleep, and emotional arousal). The final purpose is to facilitate the follow-up and precise diagnosis of apathy, towards a personalised treatment of this condition within everyday life.

Efficacy of serious exergames in improving neuropsychiatric symptoms in neurocognitive disorders: Results of the X-TORP cluster randomized trial

INTRODUCTION

The aim of this study was to evaluate the efficacy of a serious exergame in improving the neuropsychiatric symptoms of patients with neurocognitive disorders.

METHODS

X-Torp is a serious exergame combining motor and cognitive activities. Ninety-one subjects (mean age = 81.7 years, mean Mini-Mental State Examination = 18.3) were recruited in 16 centers. Centers were randomized into intervention and control centers. Subjects underwent assessment for cognitive and behavioral symptoms at baseline (BL), the end of the intervention (W12), and 12 weeks after the end of the intervention (W24).

RESULTS

The comparison of neuropsychiatric symptoms between BL and W12 and W24 showed that subjects of the intervention group improved in apathy between BL and W12. Mixed analysis (time BL, W12, W24 x group) indicated a significant increase in apathy and neuropsychiatric symptoms in the control subjects.

DISCUSSION

The use of X-Torp improved neuropsychiatric symptoms, particularly apathy. Future studies should more consistently use behavioral and neuropsychiatric symptoms as outcome measures.

Diagnostic criteria for apathy in neurocognitive disorders

INTRODUCTION

Apathy is common in neurocognitive disorders (NCD) but NCD-specific diagnostic criteria are needed.

METHODS

The International Society for CNS Clinical Trials Methodology Apathy Work Group convened an expert group and sought input from academia, health-care, industry, and regulatory bodies. A modified Delphi methodology was followed, and included an extensive literature review, two surveys, and two meetings at international conferences, culminating in a consensus meeting in 2019.

RESULTS

The final criteria reached consensus with more than 80% agreement on all parts and included: limited to people with NCD; symptoms persistent or frequently recurrent over at least 4 weeks, a change from the patient's usual behavior, and including one of the following: diminished initiative, diminished interest, or diminished emotional expression/responsiveness; causing significant functional impairment and not exclusively explained by other etiologies.

DISCUSSION

These criteria provide a framework for defining apathy as a unique clinical construct in NCD for diagnosis and further research.

Grasping Social Apathy: The Role of Reach-To-Grasp Action Kinematics for the Assessment of Social Apathy in Mild Neurocognitive Disorders

BACKGROUND

Social apathy, a reduction in initiative in proposing or engaging in social activities or interactions, is common in mild neurocognitive disorders (MND). Current apathy assessment relies on self-reports or clinical scales, but growing attention is devoted to defining more objective, measurable and non-invasive apathy proxies.

OBJECTIVE

In the present study we investigated the interest of recording action kinematics in a social reach-to-grasp task for the assessment of social apathy.

METHODS

Thirty participants took part in the study: 11 healthy controls (HC; 6 females, mean age = 68.3±10.5 years) and 19 subjects with MND (13 females, mean age = 75.7±6.3 years). Based on the Diagnostic Criteria for Apathy, MND subjects were classified as socially apathetic (A-MND, N = 9) versus non-apathetic (NA-MND, N = 10). SensRing, a ring-shaped wearable sensor, was placed on their index finger, and subjects were asked to reach and grasp a can to place it into a cup (individual condition) and pass it to a partner (social condition).

RESULTS

In the reach-to-grasp phase of the action, HC and NA-MND showed different acceleration and velocity profiles in the social versus individual condition. No differences were found for A-MND.

CONCLUSION

Previous studies showed the interest of recording patients' level of weekly motor activity for apathy assessment. Here we showed that a 10-min reach-to-grasp task may provide information to differentiate socially apathetic and non-apathetic subjects with MND, thus providing a tool easily usable in the clinical practice. Future studies with a bigger sample are needed to better characterize these findings.

Correlations Between Facial Expressivity and Apathy in Elderly People With Neurocognitive Disorders: Exploratory Study

Background

Neurocognitive disorders are often accompanied by behavioral symptoms such as anxiety, depression, and/or apathy. These symptoms can occur very early in the disease progression and are often difficult to detect and quantify in nonspecialized clinical settings.

Objective

We focus in this study on apathy, one of the most common and debilitating neuropsychiatric symptoms in neurocognitive disorders. Specifically, we investigated whether facial expressivity extracted through computer vision software correlates with the severity of apathy symptoms in elderly subjects with neurocognitive disorders.

Methods

A total of 63 subjects (38 females and 25 males) with neurocognitive disorder participated in the study. Apathy was assessed using the Apathy Inventory (AI), a scale comprising 3 domains of apathy: loss of interest, loss of initiation, and emotional blunting. The higher the scale score, the more severe the apathy symptoms. Participants were asked to recall a positive and a negative event of their life, while their voice and face were recorded using a tablet device. Action units (AUs), which are basic facial movements, were extracted using OpenFace 2.0. A total of 17 AUs (intensity and presence) for each frame of the video were extracted in both positive and negative storytelling. Average intensity and frequency of AU activation were calculated for each participant in each video. Partial correlations (controlling for the level of depression and cognitive impairment) were performed between these indexes and AI subscales.

Results

Results showed that AU intensity and frequency were negatively correlated with apathy scale scores, in particular with the emotional blunting component. The more severe the apathy symptoms, the less expressivity in specific emotional and nonemotional AUs was displayed from participants while recalling an emotional event. Different AUs showed significant correlations depending on the sex of the participant and the task’s valence (positive vs negative story), suggesting the importance of assessing male and female participants independently.

Conclusions

Our study suggests the interest of employing computer vision-based facial analysis to quantify facial expressivity and assess the severity of apathy symptoms in subjects with neurocognitive disorders. This may represent a useful tool for a preliminary apathy assessment in nonspecialized settings and could be used to complement classical clinical scales. Future studies including larger samples should confirm the clinical relevance of this kind of instrument.

Virtual reality intervention to improve apathy in residential aged care: protocol for a multisite non-randomised controlled trial

INTRODUCTION

Apathy is a prevalent neuropsychiatric symptom for older adults residing in aged care. Left untreated, apathy has been associated with accelerated cognitive decline and increased risk of mortality. Reminiscence therapy is commonly used in aged care and has demonstrated to reduce apathy. Traditional methods of reminiscence use physical objects and more recently technology including tablets and laptop computers have demonstrated potential. Virtual reality (VR) has successfully been used to treat psychological disorders; however, there is little evidence on using VR for behavioural symptoms such as apathy in older adults. Using VR to deliver reminiscence therapy provides an immersive experience, and readily available applications provide access to a large range of content allowing easier delivery of therapy over traditional forms of therapy. This study aims to identify changes in apathy after a reminiscence therapy intervention using head-mounted displays (HMDs).

METHODS AND ANALYSIS

Participants will be allocated to one of three groups; reminiscence therapy using VR; an active control using a laptop computer or physical items and a passive control. A total of 45 participants will be recruited from residential aged care (15 in each group). The three groups will be compared at baseline and follow-up. The primary outcome is apathy, and secondary outcomes include cognition and depression. Side effects from using HMDs will also be examined in the VR group. Primary and secondary outcomes at baseline and follow-up will be analysed using linear mixed modelling.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the University of South Australia Human Research Ethics Committee. The results from this study will be disseminated through manuscript publications and national/international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12619001510134.

Apathy is associated with poorer abstinence self-efficacy in individuals with methamphetamine dependence

•

Used an apathy composite T-score approach validated in methamphetamine-dependence.

•

Apathy, above other factors, associated with poorer drug abstinence self-efficacy.

•

Methamphetamine use characteristics unrelated to drug abstinence self-efficacy.

•

Social peer pressure was riskiest situation for potential methamphetamine relapse.

Background

Confidence in one’s ability to achieve and maintain drug abstinence (i.e., abstinence self-efficacy) is a strong predictor of substance use treatment outcomes. Neurobehavioral factors that may interfere with abstinence self-efficacy are less well established, particularly in methamphetamine (METH). This study investigated whether apathy, which is highly prevalent during active METH use and periods of abstinence, influences abstinence self-efficacy among METH dependent individuals.

Methods

Sixty-six participants with lifetime METH dependence and METH abuse/METH dependence diagnoses within the last 18 months (mean age [SD] = 39.5 years [10.7]), and no severe psychiatric or neurological diseases, completed the Methamphetamine Self-Efficacy Scale (MSES), alongside a comprehensive neurobehavioral evaluation. The MSES presents six situations that may lead to relapse and collects self-report ratings for two subscales: “Confidence” (i.e., confidence in one’s ability to abstain from using METH, or METH abstinence self-efficacy) and “Temptation” (i.e., how tempted one is to use METH) with regard to each situation. Apathy was measured using a composite T-score comprised of items and scales from three well-validated, self-report assessments.

Results

Multivariable linear regression found that higher Apathy T-scores were significantly associated with lower Confidence ratings (i.e., poorer METH abstinence self-efficacy; p < .05), independent of potentially relevant factors (e.g., Temptation to use METH, comorbid HIV disease, and neurocognitive impairment).

Conclusions

Elevated apathy may adversely impact one’s confidence to abstain from METH use. Findings highlight the importance of addressing apathy in order to improve METH abstinence self-efficacy, which may subsequently increase the likelihood of successful METH treatment outcomes.

The emotional disorders associated with multiple sclerosis

Multiple sclerosis (MS) is associated with a high prevalence of emotional and mood disorders. Emotional disorders may worsen during illness progression and affect the quality of life of patients and their families. MS is often associated with depression, with an increased risk of suicide, poor adherence to treatment, decreased functional status, and quality of life. The diagnosis and treatment of emotional and mood disorders in these patients is often challenging since several symptoms of these disorders overlap with those of MS. Other prevalent emotional disorders in MS include bipolar disorder, anxiety disorders, emotional blunting (apathy), and pseudobulbar affect. Early recognition and treatment of these comorbidities could contribute to the reduction of disability and even to decreased mortality. The aim of this chapter is to provide an up-to-date review of mood and emotional disorders that are often associated with MS, focusing on their epidemiology, clinical features, pathogenesis, assessment, and treatment. The interplay between the psychosocial impact of the chronic disability and the demyelinating structural lesions of the brain in precipitating emotional and mood disorders is discussed, as well as its implications for diagnosis and treatment.

Neurobiologic Rationale for Treatment of Apathy in Alzheimer's Disease With Methylphenidate

The public health burden of Alzheimer's disease (AD) is related not only to cognitive symptoms, but also to neuropsychiatric symptoms, including apathy. Apathy is defined as a quantitative reduction of goal-directed activity in comparison to a previous level of functioning and affects 30%-70% of persons with AD. Previous attempts to treat apathy in AD-both nonpharmacologically and pharmacologically-have been wanting. Catecholaminergic treatment with methylphenidate has shown encouraging results in initial trials of apathy in AD. Understanding the neuronal circuits underlying motivated behavior and their reliance on catecholamine actions helps provide a rationale for methylphenidate actions in the treatment of apathy in patients with AD. Anatomical, physiological, and behavioral studies have identified parallel, cortical-basal ganglia circuits that govern action, cognition, and emotion and play key roles in motivated behavior. Understanding the distinct contributions to motivated behavior of subregions of the prefrontal cortex-dorsolateral, orbital-ventromedial, and dorsomedial-helps to explain why degeneration of these areas in AD results in apathetic behaviors. We propose that the degeneration of the prefrontal cortex in AD produces symptoms of apathy. We further propose that methylphenidate treatment may ameliorate those symptoms by boosting norepinephrine and dopamine actions in prefrontal-striatal-thalamocortical circuits.

Reliability and validity of the brief dimensional apathy scale

OBJECTIVE

Apathy is composed of different demotivational subtypes measurable by the dimensional apathy scale (DAS) and can be quickly assessed using the brief DAS (b-DAS). The aim was to determine the reliability and validity of the b-DAS.

METHODS

53 amyotrophic lateral sclerosis (ALS) patients and 53 of their informants were recruited. Informants completed the b-DAS, the original informant/carer-rated DAS and behavioral interview about the patients (i.e., presence of behaviors such as apathy/inertia, loss of sympathy/empathy). Patients completed measures of depression, anxiety, emotional lability, cognitive functioning, and functional disability measures.

RESULTS

The b-DAS showed good internal consistency, excellent test-retest reliability, significant positive correlation with the original DAS, and no significant correlations with depression, anxiety, emotional lability, cognitive functioning or functional disability measures. Semi-structured behavior interview showed patients with apathy/inertia had significantly higher b-DAS subscale scores and patients with loss of sympathy/empathy had significantly higher emotional apathy scores only.

CONCLUSIONS

The b-DAS is a fast, reliable, and valid instrument for screening apathy subtypes independent of physical disability.

Spanish Adaptation of the Dimensional Apathy Scale (DAS) in Amyotrophic Lateral Sclerosis

Aim: To adapt, translate, and utilize the Dimensional Apathy Scale (DAS) in Amyotrophic Lateral Sclerosis (ALS) to the Spanish population. Method: We recruited 104 ALS patients (67 of their caregivers) and 49 controls. Participants completed the Spanish-translated DAS, Geriatric Depression Scale- Short form. Patients were also administered the ALS Functional Rating Scale-Revised (ALSFRS-R). Caregivers additionally completed the informant/caregiver-rated Spanish-translated DAS. The DAS was translated to Spanish using a back-translation method. Test-retest and internal consistency reliability were examined. Divergent validity was assessed by comparing the DAS with the depression scale (GDS-15). Principal Component Analysis (PCA) was applied to explore the substructure of the Spanish DAS. Results: The internal consistency reliability of self-rated Spanish DAS was 0.72 and of the informant/caregiver-rated Spanish DAS was 0.84. Correlations between self-rated DAS subscales and GDS-15 were not statistically significant, with a good test-retest reliability. PCA analysis showed a similar substructure to the original DAS. ALS patients had significantly higher Initiation apathy than controls. Additionally, ALS patient informant/caregiver-rated DAS Emotional apathy was significantly higher than the self-rated, with no significant differences observed in the Executive and Initiation subscales. No association was found between DAS and functional impairment using the ALS Functional Rating Scale (ALSFRS-R). Conclusion: The Spanish translation of the DAS is valid and reliable for use in assessing multidimensional apathy in the Spanish population. Availability of the Spanish DAS will allow for future research to explore different apathy subtypes and their impact in ALS and other conditions.

Effectiveness of Exergaming in Improving Cognitive and Physical Function in People With Mild Cognitive Impairment or Dementia: Systematic Review

BACKGROUND

Individuals with mild cognitive impairment and dementia have impaired physical and cognitive functions, leading to a reduced quality of life compared with those without such impairment. Exergaming, which is defined as a combination of exercise and gaming, is an innovative, fun, and relatively safe way to exercise in a virtual reality or gaming environment. Therefore, exergaming may help people living with mild cognitive impairment or dementia to overcome obstacles that they may experience regarding regular exercise and activities.

OBJECTIVE

The aim of this systematic review was to review studies on exergaming interventions administered to elderly individuals with mild cognitive impairment and dementia, and to summarize the results related to physical and cognitive functions such as balance, gait, executive function, and episodic memory.

METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, PsycINFO, Amed, and Nursing Database for articles published from the inception of the respective databases to January 2019. We included all clinical trials of exergaming interventions in individuals with mild cognitive impairment and dementia for review. The risk of bias was independently evaluated by two reviewers using the Cochrane Collaboration and Risk of Bias in Non-randomized Studies of Interventions tools.

RESULTS

Ten studies involving 702 participants were included for review. There was consistent evidence from 7 studies with a low risk of bias showing statistically significant effects of exergaming on cognitive functioning in people with mild cognitive impairment and dementia. With respect to physical function, 3 of 5 full-scale studies found positive results, and the intensity of most games was classified as moderate.

CONCLUSIONS

Overall, exergaming is an innovative tool for improving physical and cognitive function in people with mild cognitive impairment or dementia, although there is high heterogeneity among studies in terms of the duration, frequency, and gaming platform used. The quality of the included articles was moderate to high. More high-quality studies with more accurate outcome indicators are needed for further exploration and validation of the benefits of exergaming for this population.

Bupropion for the Treatment of Apathy in Alzheimer Disease: A Randomized Clinical Trial

IMPORTANCE

Apathy is a frequent neuropsychiatric symptom in dementia of Alzheimer type and negatively affects the disease course and patients' and caregivers' quality of life. Effective treatment options are needed.

OBJECTIVE

To examine the efficacy and safety of the dopamine and noradrenaline reuptake inhibitor bupropion in the treatment of apathy in patients with dementia of Alzheimer type.

DESIGN, SETTING, AND PARTICIPANTS

This 12-week, multicenter, double-blind, placebo-controlled, randomized clinical trial was conducted in a psychiatric and neurological outpatient setting between July 2010 and July 2014 in Germany. Patients with mild-to-moderate dementia of Alzheimer type and clinically relevant apathy were included. Patients with additional clinically relevant depressed mood were excluded. Data analyses were performed between August 2018 and August 2019.

INTERVENTIONS

Patients received either bupropion or placebo (150 mg for 4 weeks plus 300 mg for 8 weeks). In case of intolerability of 300 mg, patients continued to receive 150 mg throughout the study.

MAIN OUTCOMES AND MEASURES

Change on the Apathy Evaluation Scale-Clinician Version (AES-C) (score range, 18-72 points) between baseline and week 12 was the primary outcome parameter. Secondary outcome parameters included measures of neuropsychiatric symptoms, cognition, activities of daily living, and quality of life. Outcome measures were assessed at baseline and at 4, 8, and 12 weeks.

RESULTS

A total of 108 patients (mean [SD] age, 74.8 [5.9] years; 67 men [62%]) were included in the intention-to-treat analysis, with 54 randomized to receive bupropion and 54 randomized to receive placebo. The baseline AES-C score was comparable between the bupropion group and the placebo group (mean [SD], 52.2 [8.7] vs 50.4 [8.2]). After controlling for the baseline AES-C score, site, and comedication with donepezil or galantamine, the mean change in the AES-C score between the bupropion and placebo groups was not statistically significant (mean change, 2.22; 95% CI, -0.47 to 4.91; P = .11). Results on secondary outcomes showed statistically significant differences between bupropion and placebo in terms of total neuropsychiatric symptoms (mean change, 5.52; 95% CI, 2.00 to 9.04; P = .003) and health-related quality of life (uncorrected for multiple comparisons; mean change, -1.66; 95% CI, -3.01 to -0.31; P = .02) with greater improvement in the placebo group. No statistically significant changes between groups were found for activities of daily living (mean change, -2.92; 95% CI, -5.89 to 0.06; P = .05) and cognition (mean change, -0.27; 95% CI, -3.26 to 2.73; P = .86). The numbers of adverse events (bupropion group, 39 patients [72.2%]; placebo group, 33 patients [61.1%]) and serious adverse events (bupropion group, 5 patients [9.3%]; placebo group, 2 patients [3.7%]) were comparable between groups.

CONCLUSIONS AND RELEVANCE

Although it is safe, bupropion was not superior to placebo for the treatment of apathy in patients with dementia of Alzheimer type in the absence of clinically relevant depressed mood.

TRIAL REGISTRATION

EU Clinical Trials Register Identifier: 2007-005352-17.

Efficacy of a Web App for Cognitive Training (MeMo) Regarding Cognitive and Behavioral Performance in People With Neurocognitive Disorders: Randomized Controlled Trial

BACKGROUND

Cognitive and behavioral symptoms are the clinical hallmarks of neurocognitive disorders. Cognitive training may be offered to reduce the risks of cognitive decline and dementia and to reduce behavioral symptoms, such as apathy. Information and communication technology approaches, including serious games, can be useful in improving the playful aspect of computerized cognitive training and providing motivating solutions in elderly patients.

OBJECTIVE

The objective of this study was to assess the effectiveness of employing the MeMo (Memory Motivation) Web app with regard to cognitive and behavioral symptoms in patients with neurocognitive disorders.

METHODS

MeMo is a Web app that can be used on any Web browser (computer or tablet). The training activities proposed in MeMo are divided into the following two parts: memory and mental flexibility/attention. The study included 46 individuals (mean age 79.4 years) with a diagnosis of neurocognitive disorders at the Institut Claude Pompidou Memory Center in Nice. This randomized controlled study compared the evolution of cognition and behavior between patients not using MeMo (control group) and patients using MeMo (MeMo group) for 12 weeks (four sessions per week). Patients underwent memory and attention tests, as well as an apathy assessment at baseline, week 12 (end of the training period), and week 24 (12 weeks after the end of the training sessions). In addition, to assess the impact of high and low game uses, the MeMo group was divided into patients who used MeMo according to the instructions (about once every 2 days; active MeMo group) and those who used it less (nonactive MeMo group).

RESULTS

When comparing cognitive and behavioral scores among baseline, week 12, and week 24, mixed model analysis for each cognitive and behavioral score indicated no significant interaction between testing time and group. On comparing the active MeMo group (n=9) and nonactive MeMo group (n=13), there were significant differences in two attention tests (Trial Making Test A [P=.045] and correct Digit Symbol Substitution Test items [P=.045]) and in the Apathy Inventory (AI) (P=.02). Mixed analysis (time: baseline, week 12, and week 24 × number of active days) indicated only one significant interaction for the AI score (P=.01), with a significant increase in apathy in the nonactive MeMo group.

CONCLUSIONS

This study indicates that the cognitive and behavioral efficacies of MeMo, a Web-based training app, can be observed only with regular use of the app. Improvements were observed in attention and motivation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04142801; https://clinicaltrials.gov/ct2/show/NCT04142801.