Apathy Subtypes Research Articles

Mouse Model of Parkinson's Disease with Bilateral Dorsal Striatum Lesion with 6-Hydroxydopamine Exhibits Cognitive Apathy-like Behavior.

Among the symptoms of Parkinson's disease (PD), apathy comprises a set of behavioral, affective, and cognitive features that can be classified into several subtypes. However, the pathophysiology and brain regions that are involved in these different apathy subtypes are still poorly characterized. We examined which subtype of apathy is elicited in a mouse model of PD with 6-hydroxydopamine (6-OHDA) lesions and the behavioral symptoms that are exhibited. Male C57/BL6J mice were allocated to sham (n = 8) and 6-OHDA (n = 13) groups and locally injected with saline or 4 µg 6-OHDA bilaterally in the dorsal striatum. We then conducted motor performance tests and apathy-related behavioral experiments. We then pathologically evaluated tyrosine hydroxylase (TH) immunostaining. The 6-OHDA group exhibited significant impairments in motor function. In the behavioral tests of apathy, significant differences were observed between the sham and 6-OHDA groups in the hole-board test and novelty-suppressed feeding test. The 6-OHDA group exhibited impairments in inanimate novel object preference, whereas social preference was maintained in the three-chamber test. The number of TH+ pixels in the caudate putamen and substantia nigra compacta was significantly reduced in the 6-OHDA group. The present mouse model of PD predominantly showed dorsal striatum dopaminergic neuronal loss and a decrease in novelty seeking as a symptom that is related to the cognitive apathy component.

Validation of the self-rated Dimensional Apathy Scale in community stroke survivors

Apathy, a disorder of motivation observed in up to 40% of stroke survivors, is negatively associated with stroke rehabilitation outcomes. Different apathy subtypes have been identified in other conditions, but there is currently no validated multidimensional measure of post-stroke apathy (PSAp). The Dimensional Apathy Scale (DAS) assesses apathy across three subtypes: Executive, Emotional and Initiation apathy. We aimed to determine if the DAS is a reliable and valid tool to detect and characterise apathy in stroke. Fifty-three stroke survivors, (45.3% males, median age 54), and 71 people without stroke (26.8% males, median age 45) completed measures of apathy (DAS, Apathy Evaluation Scale, AES), depression (Patient Hospital Questionnaire, PHQ-9) and anxiety (Generalised Anxiety Disorder scale, GAD-7) as part of an online survey. The DAS showed high internal consistency and convergent validity with the current gold standard unidimensional assessment for apathy (AES) and divergent validity with depression (PHQ-9) and anxiety (GAD-7). Stroke survivors scored significantly higher on the total score of the DAS and all subscales, compared with controls. There were however no significant differences on depression and anxiety scores between the two groups. Our results suggest the DAS is a reliable and valid screening tool to detect and characterise PSAp.

Intellectual Curiosity and Action Initiation are Subtypes of Apathy Affected in Huntington Disease Gene Expansion Carriers.

Apathy is a prevalent behavioral syndrome of Huntington disease (HD) that can result in severe loss of function for the individual with HD and substantial caregiver distress. Research-based evidence of apathy is characterized by methodological differences, and there is a deficiency in the evidence concerning the subtypes of apathy. To characterize apathy in premanifest and motor-manifest HD gene expansion carriers and controls using the Short Problem Behaviors Assessment for Huntington's Disease (PBA-s) and the Lille Apathy Rating Scale (LARS). We included 82 HD gene expansion carriers (premanifest and motor manifest) and 32 controls (Mini-Mental State Examination score ≥24 and Montreal Cognitive Assessment score ≥19) in the study. We quantified apathy using the PBA-s and the LARS and performed correlation analyses between the global LARS score and motor function, cytosine-adenine-guanine repeat length, cytosine-adenine-guanine Age Product score, and neuropsychiatric and cognitive symptoms. The motor-manifest HD gene expansion carriers scored significantly higher than the controls on the global score and the Intellectual Curiosity and Action Initiation subscales of the LARS. Apathy was present in 28% of the HD gene expansion carriers (including 7 premanifest). The apathetic participants had a significantly higher motor score, significantly higher scores on the neuropsychiatric instruments, and significantly lower cognitive scores compared with the controls. Apathy is a frequent syndrome that is found in individuals with HD. Apathy has a specific expression, with symptoms such as reduced initiation, voluntary actions, and interests, that might be related to the underlying neuropathology. Apathy is related to disease progression, neuropsychiatric symptoms, and cognitive impairments.

Intellectual curiosity and action initiation are subtypes of apathy affected in Huntington’s disease gene expansion carriers

AbstractBackgroundApathy is a prevalent behavioral symptom in neurodegenerative diseases. In Huntington’s Disease, apathy can result in severe loss of function for the patient and substantial caregiver distress. The research‐based evidence of apathy is characterized by a lack of generalizability due to methodological differences. In this study we wished to characterize apathy in premanifest and motor‐manifest Huntington’s Disease gene expansion carriers and controls.Method82 Huntington’s Disease gene expansion carriers (premanifest and motor‐manifest) and 32 controls were included in the study (Mini‐Mental State Examination score ≥ 24 and Montreal Cognitive Assessment score ≥ 19). Apathy was quantified using the Lille Apathy Rating Scale and the Short Problem Behaviors Assessment for Huntington’s Disease. Analyses of association were performed between apathy on the Lille Apathy Rating Scale and motor function, cytosine‐adenine‐guanine repeat length, cytosine‐adenine‐guanine age product score, neuropsychiatric and cognitive screening tests.ResultCompared to premanifest and control participants, the motor‐manifest Huntington’s Disease gene expansion carriers scored significantly higher on the global score on the Lille Apathy Rating Scale and on two subscales (Intellectual Curiosity and Action Initiation – see table 1). Likewise, motor‐manifest HD gene expansion carriers scored significantly higher on the Short Problem Behaviors Assessment for Huntington’s Disease. Significant correlations were found between apathy on the Lille Apathy Rating Scale and the motor score, the neuropsychiatric measures and the cognitive screening tests. Apathy was present in 22 % of the Huntington’s Disease gene expansion carriers (including four premanifest participants) when examined with the Lille Apathy Rating Scale. The apathetic participants had significantly higher motor score and were significantly affected on the neuropsychiatric measures and the cognitive screening tests. When entered a multiple stepwise regression model, apathy was predicted by the motor score and the depression score. No other variables could significantly predict apathy on the Lille Apathy Rating Scale.ConclusionApathy is a frequent and early symptom of disease in Huntington’s Disease gene expansion carriers, and it has a specific expression that might be related to the underlying neuropathology. Apathy is related to disease progression, cognitive decline and neuropsychiatric symptoms.

The use of the French Dimensional Apathy Scale (f-DAS) to assess apathy in schizophrenia: Properties and profiles

BackgroundApathy can be defined as a quantitative reduction of self-generated voluntary and purposeful (or goal-directed) behaviour. The literature underlines the triadic dimensional nature of apathy, but in schizophrenia there are inconsistencies due to difficulty in assessment. The Dimensional Apathy Scale (DAS) and its validation into French (f-DAS) provide measurement of three neurobehavioral apathy subtypes: Executive, Emotional and Initiation, but these subtypes have never been explored in schizophrenia. ObjectiveThe aims of this study are to assess apathy in schizophrenia with a tri-dimensional tool (the f-DAS), to examine its psychometric properties in schizophrenia and the apathetic profiles of patients with schizophrenia. MethodsOne hundred and ten subjects were recruited. Forty-five belonged to the patients’ group and fifty-five to the control group. They all completed the Mini-International Neuropsychiatric Interview (M.I.N.I), the French National Reading Test (f-NART), the French Dimensional Apathy Scale (f-DAS), the Lille Apathy Rating Scale (LARS) and the Beck Depression Inventory (BDI II). ResultsRegarding the total score of the f-DAS and the subscores for each dimension, patients appeared significantly more apathetic than healthy controls. Consistency, validity, concurrent and divergent validity were good. In the patient group, several profiles of apathy were identified. ConclusionsThe f-DAS has good psychometric properties and provides reliable and valid dimensional assessment of apathy in schizophrenia. From a dimensional point of view, using the f-DAS we demonstrated that prevalence of apathy could be underestimated in schizophrenia. Patients with schizophrenia are more impaired on the Executive and Initiative dimensions of apathy.

Apathy is associated with parietal cortical-subcortical dysfunction in ALS

Apathy is the core behavioural feature of frontotemporal dysfunction in amyotrophic lateral sclerosis (ALS). Initiation and emotional manifestations of apathy significantly affect patients and carers, particularly in terms of quality of life. As such, the primary aim of the present study was to investigate the prevalence and neural correlates of initiation, and emotional subtypes of apathy in ALS. A total of 109 participants were recruited from a specialised, tertiary referral ALS/FTD clinic. Overall rates of apathy, including cognitive, initiation and emotion subtypes as assessed by the Dimensional Apathy Scale (DAS), were examined and correlated with brain volumes, including voxel-based morphometry on high resolution MRI. Clinically significant apathy ranged between 49% (patient-rated DAS) and 64% (carer-rated DAS), with the most common apathy subtypes being initiation (84–96%) and emotional (74–75%) apathy. The results of the two-way repeated measures ANOVA revealed significant differences across the DAS executive, emotional and initiation subscales (p = .0001). Multivariate analysis using a logistic regression model showed that only initiation; (odds ratio = 3.08, p = .004) and emotional (odds ratio = 2.40, p = .008) apathy were predictive of clinically significant apathy, controlling for education and depression. Increased initiation apathy correlated with reduced grey matter within bilateral superior frontal gyrus and increased emotional apathy correlated with reduced grey matter in prefrontal cortices and right anterior cingulate, previously implicated in apathy. Additional correlations were identified including the angular gyrus (or the temporo-parietal junction), important in reward valuation and subsequent goal-directed behaviour. Taken together, results from the present series highlight the frequency and multi-dimensionality of apathy in ALS. The pathophysiological mechanisms of apathy in ALS may be critically underpinned by neurodegeneration across a distributed brain network, with key roles in task initiation, emotion, reward processing and subsequent goal-directed behaviour.

Multidimensional Apathy: The Utility of the Dimensional Apathy Scale in Huntington's Disease.

Apathy is a disorder of motivation common to Huntington's disease (HD). Recent conceptual frameworks suggest that apathy is not unitary but consists of discrete subtypes ("dimensions"). Which of the proposed dimensions are preferentially affected in HD, and how these dimensions evolve with disease progression is unknown. The Dimensional Apathy Scale (DAS) separates apathy into Executive, Initiation and Emotional subscales. Using the DAS, we aimed to: 1) Determine the apathy subtypes prevalent in HD; 2) Compare the DAS against a unitary measure of apathy (Apathy Evaluation Scale, AES); 3) Assess the reliability of self- and observer-ratings; and 4) Determine the relationship between the DAS, and disease burden, total functional capacity (TFC) and the AES. Fifty pre-manifest, 51 manifest-HD, 87 controls, and 50 HD-observers completed the DAS, AES, and TFC. Manifest-HD participants had the highest levels of apathy across all dimensions (30.4% on Executive subscale, 34.8% on Initiation subscale, and 15.2% on Emotional subscale), relative to pre-manifest and control participants. Self- and observer-ratings on the DAS did not differ. Hierarchical regressions across the entire gene-expanded sample showed that scores on the Initiation subscale correlated with AES scores; higher Executive subscale scores were related to higher disease burden; and Emotional subscale scores with lower total functional capacity. In this first study of the DAS in HD, manifest-HD participants were more apathetic than pre-manifest and control participants across all apathy subtypes. The DAS may be a useful tool for measuring different aspects of apathy in people with HD.

Delineation of Apathy Subgroups in Parkinson's Disease: Differences in Clinical Presentation, Functional Ability, Health-related Quality of Life, and Caregiver Burden.

Apathy is a prevalent, multidimensional neuropsychiatric condition in Parkinson's disease (PD). Several authors have proposed apathy subtypes in PD, but no study has examined the classification of PD patients into distinct apathy subtypes, nor has any study examined the clinical utility of doing so. The current study used a data-driven approach to explore the existence and associated clinical characteristics of apathy subtypes in PD. The Apathy Scale (AS) was administered to 157 non-demented individuals with PD. Participants were classified into apathy subgroups through cluster analysis. Differences among apathy subtypes on external clinical indicators were explored across apathy subgroups. Individuals with PD were classified into three subgroups: a Non-Apathetic group with low levels of apathy symptoms, a Low Interest/Energy group, characterized by elevated symptoms of low interest/energy and minimal low initiation/emotional indifference symptoms, and a Low Initiation group, characterized by an absence of low interest/energy symptoms and elevated levels of low initiation/emotional indifference symptoms. Both Low Interest/Energy and Low Initiation groups exhibited worse depression, fatigue, anxiety, health-related quality of life, and caregiver burden than the Non-Apathetic subgroup. The Low Initiation group exhibited worse overall cognition, emotional well-being, state anxiety, communicative ability, and functional ability than the Low Interest/Energy group. Importantly, disease-related characteristics did not differ across apathy symptom subgroups. Non-demented PD patients can be separated into distinct apathy symptom subgroups, which are differentially associated with important clinical variables. Apathy subgroup membership may reflect disruption to different neural systems independent of disease progression.

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.

Multidimensional Apathy in Behavioral Variant Frontotemporal Dementia, Primary Progressive Aphasia, and Alzheimer Disease.

Apathy is prevalent in dementia, such as behavioral variant frontotemporal dementia (bvFTD), primary progressive aphasia (PPA), and Alzheimer disease (AD). As a multidimensional construct, it can be assessed and subsumed under a Dimensional Apathy Framework. A consistent apathy profile in bvFTD and PPA has yet to be established. The aim was to explore apathy profiles and awareness in bvFTD, PPA, and AD. A total of 12 patients with bvFTD, 12 patients with PPA, 28 patients with AD, and 20 matched controls, as well as their informants/carers, were recruited. All participants completed the Dimensional Apathy Scale (DAS), assessing executive, emotional, and initiation apathy subtypes, a 1-dimensional apathy measure, depression measure, and functional and cognitive screens. Apathy subtype awareness was determined through DAS informant/carer and self-rating discrepancy. Apathy profile comparison showed patients with bvFTD had significantly higher emotional apathy than patients with AD (P < .01) and significantly higher apathy over all subtypes than patients with PPA (Ps < .05). Additionally, patients with bvFTD had significantly lower awareness for emotional apathy (P < .01) when compared to patients with AD and PPA. All patient groups had significant global apathy over all subtypes compared to controls. The emergent apathy profile for bvFTD seems to be emotional apathy (indifference or emotional/affective neutrality), with lower self-awareness in this subtype. Further, lower self-awareness for executive apathy (lack of motivation for planning, organization, or attention) differentiates bvFTD from PPA. Future research should investigate the cognitive and neural correlates as well as the practical impact of apathy subtypes.

Reliability and validity of the brief dimensional apathy scale.

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

The brief Dimensional Apathy Scale: A short clinical assessment of apathy

Objective: Apathy is a prominent syndrome across neurodegenerative diseases. The Dimensional Apathy Scale (DAS) assesses three apathy subtypes—executive, emotional, and initiation—and is sensitive and valid in amyotrophic lateral sclerosis (ALS), Alzheimer’s disease (AD), and Parkinson’s disease. This study describes the development of the brief DAS (b-DAS), which will enable apathy to be swiftly detected in the clinic.Method: 102 ALS and 102 AD patients’ previously collected data were used. Mokken analyses were performed on item-level data of each informant/carer-rated DAS subscale (executive, emotional, and initiation) for the initial scale reduction. Item-total correlational analyses against standard apathy (convergent validity criteria) and depression (divergent validity criteria) measures and qualitative examination of items aided final item selection. Receiver operating curve analysis determined optimal cutoffs for the reduced subscales.Results: Mokken analyses suggested unidimensionality of each DAS subscale. Three items were removed that failed to satisfy monotone homogeneity model requirements, three items were removed due to validity criteria not being met, and six items were removed due to a combination of lower item scalability and item-total correlations. Item-theme examination further reduced the b-DAS to nine items, three per subscale, with a supplemental awareness deficit assessment being added. Sensitivity- and specificity-based optimal cutoffs were calculated for each b-DAS subscale.Conclusions: This study presents the b-DAS, an informant/carer-based robust yet short multidimensional apathy instrument with good convergent and divergent validity, with recommended clinical cutoffs. The b-DAS is appropriate for use in the clinic and for research to quickly and comprehensively screen for apathy subtype impairments.

Apathy Associated With Impaired Recognition of Happy Facial Expressions in Huntington's Disease.

Previous research has demonstrated an association between emotion recognition and apathy in several neurological conditions involving fronto-striatal pathology, including Parkinson's disease and brain injury. In line with these findings, we aimed to determine whether apathetic participants with early Huntington's disease (HD) were more impaired on an emotion recognition task compared to non-apathetic participants and healthy controls. We included 43 participants from the TRACK-HD study who reported apathy on the Problem Behaviours Assessment - short version (PBA-S), 67 participants who reported no apathy, and 107 controls matched for age, sex, and level of education. During their baseline TRACK-HD visit, participants completed a battery of cognitive and psychological tests including an emotion recognition task, the Hospital Depression and Anxiety Scale (HADS) and were assessed on the PBA-S. Compared to the non-apathetic group and the control group, the apathetic group were impaired on the recognition of happy facial expressions, after controlling for depression symptomology on the HADS and general disease progression (Unified Huntington's Disease Rating Scale total motor score). This was despite no difference between the apathetic and non-apathetic group on overall cognitive functioning assessed by a cognitive composite score. Impairment of the recognition of happy expressions may be part of the clinical picture of apathy in HD. While shared reliance on frontostriatal pathways may broadly explain associations between emotion recognition and apathy found across several patient groups, further work is needed to determine what relationships exist between recognition of specific emotions, distinct subtypes of apathy and underlying neuropathology. (JINS, 2019, 25, 453-461).

White matter cortico-striatal tracts predict apathy subtypes in Huntington's disease.

BackgroundApathy is the neuropsychiatric syndrome that correlates most highly with Huntington's disease progression, and, like early patterns of neurodegeneration, is associated with lesions to cortico-striatal connections. However, due to its multidimensional nature and elusive etiology, treatment options are limited.ObjectivesTo disentangle underlying white matter microstructural correlates across the apathy spectrum in Huntington's disease.MethodsForty-six Huntington's disease individuals (premanifest (N = 22) and manifest (N = 24)) and 35 healthy controls were scanned at 3-tesla and underwent apathy evaluation using the short-Problem Behavior Assessment and short-Lille Apathy Rating Scale, with the latter being characterized into three apathy domains, namely emotional, cognitive, and auto-activation deficit. Diffusion tensor imaging was used to study whether individual differences in specific cortico-striatal tracts predicted global apathy and its subdomains.ResultsWe elucidate that apathy profiles may develop along differential timelines, with the auto-activation deficit domain manifesting prior to motor onset. Furthermore, diffusion tensor imaging revealed that inter-individual variability in the disruption of discrete cortico-striatal tracts might explain the heterogeneous severity of apathy profiles. Specifically, higher levels of auto-activation deficit symptoms significantly correlated with increased mean diffusivity in the right uncinate fasciculus. Conversely, those with severe cognitive apathy demonstrated increased mean diffusivity in the right frontostriatal tract and left dorsolateral prefrontal cortex to caudate nucleus tract.ConclusionsThe current study provides evidence that white matter correlates associated with emotional, cognitive, and auto-activation subtypes may elucidate the heterogeneous nature of apathy in Huntington's disease, as such opening a door for individualized pharmacological management of apathy as a multidimensional syndrome in other neurodegenerative disorders.

Psychometric Properties of Apathy Scales in Dementia: A Systematic Review.

Apathy is a prevalent and problematic neuropsychiatric symptom in those with dementia that is emerging as a treatment target, necessitating accurate assessment. While many apathy scales are available, not all have been developed for use exclusively in dementia, and psychometric properties may vary across different populations. This systematic review aimed to provide an overview of the psychometric properties of apathy scales used in Alzheimer's disease (AD) and related dementias, as well as rate the methodological quality of supporting studies. In addition, for those scales identified, performance in clinical trials was reviewed. A search was conducted through Medline, Psychinfo, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. Articles that reported psychometric properties of an apathy scale in an AD or mixed dementia population were included. Of 15 articles, the methodological quality ratings of the studies ranged from adequate to excellent. Three clinical trials and two pooled analyses of clinical trials were included that used apathy scales evaluated in this review. Three scales emerged. The Neuropsychiatric Inventory apathy subscale (NPI-apathy) and the Apathy Evaluation Scale (AES) had the greatest number of studies evaluating psychometric properties and were also used in the clinical trials and have shown sensitivity to change. The Dementia Apathy Interview and Rating demonstrated excellent values of internal consistency, validity, and reliability for use in an AD population. Future research should address comparative scale performance and assess ability to distinguish subtypes of apathy. Validation may include evaluation of performance against specific imaging defined deficits.

The cognitive, affective motivational and clinical longitudinal determinants of apathy in schizophrenia.

Apathy is a frequent and debilitating condition with few treatment options available in schizophrenia patients. Despite evidence of its multidimensional structure, most of past studies have explored apathy through a categorical approach. The main objective of this study was to identify the cognitive, emotional, motivational, and clinical factors at baseline that best predicted the three subtypes of apathy dimensions at follow-up. In a longitudinal study, 137 participants diagnosed with schizophrenia underwent different assessments including clinical, motivational, affective and cognitive measurements, at 1-month (referred to as baseline) and 12-month follow-ups. Data were analyzed using partial least squares variance-based structural equation modeling. Three latent variables representing the three previously described domains of apathy reaching consensus in the literature were extracted from the Lille Apathy Rating Scale. Results showed that in addition to baseline apathy, positive symptoms, anticipatory pleasure and sensibility to punishment at baseline predicted cognitive apathy at follow-up. Likewise, both baseline apathy and sensibility to punishment predicted emotional apathy at follow-up. Finally, baseline anhedonia and episodic memory were the main variables the predicted behavioral apathy at follow-up. This is the first study to show specific associations between apathy subtypes and clinical and cognitive motivational dysfunction in individual with schizophrenia, indicating possible distinct underlying mechanisms to these demotivational symptoms. Treatment for apathy should address both types of processes. Importantly, our results demonstrate the interest of multidimensional approaches in the understanding of apathy in schizophrenia.

A Novel Assessment and Profiling of Multidimensional Apathy in Alzheimer's Disease.

Apathy is a complex multidimensional syndrome frequently reported in Alzheimer's disease (AD) and is associated with impaired awareness. Here we present a psychometrically robust method to profile apathy in AD. To determine the validity and reliability of a multidimensional apathy measure, the Dimensional Apathy Scale (DAS), and explore the apathy subtype profile and its associations in AD. 102 people with AD and 55 healthy controls were recruited. Participants completed the DAS, the Apathy Evaluation Scale (AES), Geriatric Depression Short form (GDS-15), and Lawton Instrumental Activities of Daily Living (LIADL). Psychometric properties of the DAS were determined. AD-Control comparison was performed to explore group differences on the DAS. Latent Class Analysis (LCA) was used to explore the profile of apathy in AD. The DAS had a good to excellent Cronbach's standardized alpha (self-rated = 0.85, informant/carer-rated = 0.93) and good convergent and divergent validity against standard apathy (AES) and depression (GDS-15) measures. Group comparison showed people with AD were significantly higher for all apathy subtypes than controls (p < 0.001), and lacking in awareness over all apathy subtype deficits. LCA showed three distinct AD subgroups, with 42.2% in the Executive-Initiation apathy, 28.4% in the Global apathy, and 29.4% in the Minimal apathy group. The DAS is a psychometrically robust method of assessing multidimensional apathy in AD. The apathy profiles in AD are heterogeneous, with additional specific impairments relating to awareness dependent on apathy subtype.

Multidimensional apathy and executive dysfunction in amyotrophic lateral sclerosis

Apathy and cognitive dysfunction are prominent symptoms of Amyotrophic lateral sclerosis (ALS). More specifically ALS patients show increased Initiation apathy-a lack of motivation for self-generation of thoughts as assessed by the Dimensional Apathy Scale. This study aimed to investigate the cognitive underpinnings of apathy subtypes in ALS. We hypothesized that increased Initiation apathy would be associated deficits on tests of intrinsic response generation, such as verbal fluency. We also explored the relationship of other apathy subtypes to cognitive processes, in particular emotional apathy with emotional and social cognition deficits and executive apathy with planning and goal management deficits. ALS patients, and their carers (N = 30), and healthy matched controls, and their informants (N = 29) were recruited. All participants completed self- and informant/carer-rated Dimensional Apathy Scale, to quantify apathy subtypes (Executive, Emotional and Initiation), along with standard apathy and depression measures. Patients and controls completed the Edinburgh Cognitive and behavioural ALS Screen, and a comprehensive neuropsychological battery including emotional recognition, social cognition, intrinsic response generation tasks (verbal fluency and random number generation) and a new ecologically valid, computerised measure of planning and goal management. The results demonstrated that increased Initiation apathy was the only significantly elevated subtype in ALS (self-rated p < .05, informant/carer-rated p < .01). Initiation apathy was found to be significantly associated with verbal fluency deficit, while Emotional apathy was significantly associated with emotional recognition deficits. No associations were found between apathy subtypes and depression or in controls. This is the first study to show specific associations between apathy subtypes (Emotional and Initiation) and executive and emotional cognitive dysfunction, indicating possible distinct underlying mechanisms to these demotivational symptoms.

Distinct Subtypes of Apathy Revealed by the Apathy Motivation Index

Apathy is a debilitating but poorly understood disorder characterized by a reduction in motivation. As well as being associated with several brain disorders, apathy is also prevalent in varying degrees in healthy people. Whilst many tools have been developed to assess levels of apathy in clinical disorders, surprisingly there are no measures of apathy suitable for healthy people. Moreover, although apathy is commonly comorbid with symptoms of depression, anhedonia and fatigue, how and why these symptoms are associated is unclear. Here we developed the Apathy-Motivation Index (AMI), a brief self-report index of apathy and motivation. Using exploratory factor analysis (in a sample of 505 people), and then confirmatory analysis (in a different set of 479 individuals), we identified subtypes of apathy in behavioural, social and emotional domains. Latent profile analyses showed four different profiles of apathy that were associated with varying levels of depression, anhedonia and fatigue. The AMI is a novel and reliable measure of individual differences in apathy and might provide a useful means of probing different mechanisms underlying sub-clinical lack of motivation in otherwise healthy individuals. Moreover, associations between apathy and comorbid states may be reflective of problems in different emotional, social and behavioural domains.

Latent class analysis of the Apathy Scale does not identify subtypes of apathy in general population-based older persons.

To identify clinically relevant subtypes of apathy in older persons using latent class analysis (LCA) and investigate the distribution of different characteristics across these subtypes. Cross-sectional data of 122 older persons (mean age 84 years, 60% female) participating in the general population-based PROactive Management Of Depression in the Elderly study, with apathy according to a score of 14 or higher on the Apathy Scale, were included for LCA. All 14 items of the Apathy Scale were used as indicator variables. Several characteristics were examined including sociodemographics, depressive, and anxiety symptoms; global cognitive function; quality of life indicators; hazardous alcohol intake (drinking ≥ 14 consumptions per week); and perceived chronic pain. Three distinct LCA classes were found classifying 17%, 7%, and 76% of the participants respectively. Individuals in the first class had a higher level of education and were less likely to live alone. Those in the second class had higher apathy and depression scores, lived more frequently alone and used more alcohol. Individuals in the third class showed a lower level of education and worse cognitive function. In multivariable multinomial analyses, only a lower educational level and higher scores on the Apathy Scale were significant predictors for class membership. Differences between LCA-derived classes were minimal, suggesting that in a general population-based cohort the Apathy Scale measures a homogeneous construct. Copyright © 2016 John Wiley & Sons, Ltd.