Quantifying motivational deficits and apathy: a review of the literature

Evaluation of apathy in non-clinical populations: validation, psychometric properties, and normative data of the Italian version of Apathy-Motivation Index (AMI)

INTRODUCTION

Evaluation of apathy in non-clinical populations is relevant to identify individuals at risk for developing cognitive decline in later stages of life, and it should be performed with questionnaires specifically designed for healthy individuals, such as the Apathy-Motivation Index (AMI); therefore, the aim of the present study was to validate the AMI in a healthy Italian population, and to provide normative data of the scale.

MATERIALS AND METHODS

Data collection was performed using a survey completed by 500 healthy participants; DAS, MMQ-A, BIS-15, PHQ-9, and GAD-7 were used to investigate convergent and divergent validity. Internal consistency and factorial structure were also evaluated. A regression-based procedure and receiver operating characteristics (ROC) analyses were used to evaluate the influence of socio-demographic variables on AMI scores and to provide adjusting factors and three cut-offs for the detection of mild, moderate, and severe apathy.

RESULTS

The Italian version of the AMI included 17 items (one item was removed because it was not internally consistent) and demonstrated good psychometric properties. The three-factor structure of AMI was confirmed. Multiple regression analysis revealed no effect of sociodemographic variables on the total AMI score. ROC analyses revealed three cut-offs of 1.5, 1.66, and 2.06 through the Youden's J statistic to detect mild, moderate, and severe apathy, respectively.

CONCLUSION

The Italian version of the AMI reported similar psychometric properties, factorial structure, and cut-offs to the original scale. This may help researchers and clinicians to identify people at risk and address them in specific interventions to lower their apathy levels.

Elevated Effort Cost Identified by Computational Modeling as a Distinctive Feature Explaining Multiple Behaviors in Patients With Depression

BACKGROUND

Motivational deficit is a core clinical manifestation of depression and a strong predictor of treatment failure. However, the underlying mechanisms, which cannot be accessed through conventional questionnaire-based scoring, remain largely unknown. According to decision theory, apathy could result either from biased subjective estimates (of action costs or outcomes) or from dysfunctional processes (in making decisions or allocating resources).

METHODS

Here, we combined a series of behavioral tasks with computational modeling to elucidate the motivational deficits of 35 patients with unipolar or bipolar depression under various treatments compared with 35 matched healthy control subjects.

RESULTS

The most striking feature, which was observed independent of medication across preference tasks (likeability ratings and binary decisions), performance tasks (physical and mental effort exertion), and instrumental learning tasks (updating choices to maximize outcomes), was an elevated sensitivity to effort cost. By contrast, sensitivity to action outcomes (reward and punishment) and task-specific processes were relatively spared.

CONCLUSIONS

These results highlight effort cost as a critical dimension that might explain multiple behavioral changes in patients with depression. More generally, they validate a test battery for computational phenotyping of motivational states, which could orientate toward specific medication or rehabilitation therapy, and thereby help pave the way for more personalized medicine in psychiatry.

Extracting Apathy From Depression Syndrome in Traumatic Brain Injury by Using a Clustering Method

OBJECTIVE

Depression and apathy are common after traumatic brain injury (TBI), and different intervention strategies are recommended for each. However, a differential diagnosis can be difficult in clinical settings, especially given that apathy is considered to be a symptom of depression. In this study, the investigators aimed to isolate apathy from depression among patients with TBI and to examine whether apathy is exclusively associated with the amount of daily activity, as previously reported in the literature.

METHODS

Eighty-eight patients with chronic TBI completed the Japanese versions of the 21-item Beck Depression Inventory-II (BDI-II) and the Starkstein Apathy Scale (AS). Daily activity was measured with a 24-hour life log. A hierarchical cluster analysis was applied to divide the BDI-II data into separable components, and components' correlations with results of the AS and 24-hour life log scale were evaluated.

RESULTS

The BDI-II and AS revealed that 37 patients (42.0%) had both depression and apathy. BDI-II data were classified into four separate clusters (somatic symptoms, loss of self-worth, affective symptoms, and apathy symptoms). Loss of self-worth and apathy symptoms subscores were significantly positively correlated with total AS score (r=0.32, p=0.002, and r=0.52, p<0.001, respectively). The apathy symptoms subscore was significantly correlated with the amount of daily activity (r=-0.29, p=0.009).

CONCLUSIONS

The findings suggest that the BDI-II can differentiate between apathy and depression among patients with TBI, which is essential when selecting intervention options. Moreover, apathy symptoms predicted patients' real-life daily activity.

Validation of a European Spanish adaptation of the Apathy Evaluation Scale-self-rated version (AES-S) in patients with schizophrenia

INTRODUCTION

Apathy is a negative symptom of schizophrenia and is associated with poor real world functioning. Therefore, it is important to have validated psychometric instruments to assess this symptom. This is the first study to validate the Spanish adaptation of the self-rated version of the Apathy Assessment Scale (AES-S) in patients with schizophrenia.

MATERIALS AND METHODS

Naturalistic, cross-sectional, validation study in 104 patients with schizophrenia evaluated using the following scales: Clinical Global Impression-Severity (CGI-S), Personal and Social Performance (PSP), Clinical Assessment Interview for Negative Symptoms (CAINS), Self-report of Negative Symptoms (SNS), Motivation and Pleasure Scale-Self-Report (MAP-SR), Calgary Depression Scale for Schizophrenia (CDSS), and Apathy Evaluation Scale-self-rated version (AES-S).

RESULTS

Reliability: Internal consistency (Cronbach's alpha) was 0.908. Convergent validity: The Pearson correlation coefficient between AES-S and CAINS-MAP total scores was -0.483 (p<0.001). For SNS, total and avolition subscale scores were -0.803 and -0.639 (p<0.001), respectively. With the MAP-SR, the correlation coefficient was -0.727 (p<0.001). Divergent validity: The Pearson correlation coefficient between AES-S and PSP total scores was 0.504 (p<0.001). Furthermore, with the CDSS, the correlation coefficient was -0.431 (p<0.001). Discriminant validity: The AES-S discriminated between different levels of illness severity according to CGI-S scores. Factor analysis: A three-component solution explained 57.32% of the variance. Pearson correlations between coefficients were 1-2=0.265, 1-3=0.464, and 2-3=0.060.

CONCLUSION

The Spanish AES-S is a reliable and valid instrument for assessing apathy in Spanish patients with schizophrenia. It seems to be appropriate for use in everyday clinical practice as a means of monitoring apathy in these patients.

Validation of a European Spanish adaptation of the Apathy Evaluation Scale-self-rated version (AES-S) in patients with schizophrenia

INTRODUCTION

Apathy is a negative symptom of schizophrenia and is associated with poor real world functioning. Therefore, it is important to have validated psychometric instruments to assess this symptom. This is the first study to validate the Spanish adaptation of the self-rated version of the Apathy Assessment Scale (AES-S) in patients with schizophrenia.

MATERIALS AND METHODS

Naturalistic, cross-sectional, validation study in 104 patients with schizophrenia evaluated using the following scales: Clinical Global Impression-Severity (CGI-S), Personal and Social Performance (PSP), Clinical Assessment Interview for Negative Symptoms (CAINS), Self-report of Negative Symptoms (SNS), Motivation and Pleasure Scale-Self-Report (MAP-SR), Calgary Depression Scale for Schizophrenia (CDSS), and Apathy Evaluation Scale-self-rated version (AES-S).

RESULTS

Reliability: Internal consistency (Cronbach's alpha) was 0.908. Convergent validity: The Pearson correlation coefficient between AES-S and CAINS-MAP total scores was -0.483 (p<0.001). For SNS, total and avolition subscale scores were -0.803 and -0.639 (p<0.001), respectively. With the MAP-SR, the correlation coefficient was -0.727 (p<0.001). Divergent validity: The Pearson correlation coefficient between AES-S and PSP total scores was 0.504 (p<0.001). Furthermore, with the CDSS, the correlation coefficient was -0.431 (p<0.001). Discriminant validity: The AES-S discriminated between different levels of illness severity according to CGI-S scores. Factor analysis: A three-component solution explained 57.32% of the variance. Pearson correlations between coefficients were 1-2=0.265, 1-3=0.464, and 2-3=0.060.

CONCLUSION

The Spanish AES-S is a reliable and valid instrument for assessing apathy in Spanish patients with schizophrenia. It seems to be appropriate for use in everyday clinical practice as a means of monitoring apathy in these patients.

Empirical support for the vascular apathy hypothesis: A structured review

OBJECTIVES

A systematic review of the relationship between subclinical small vessel disease (SSVD) in the general population and apathy to examine the hypothesis that apathy has a vascular basis.

METHODS

We searched for studies on associations between apathy and SSVD, operationalized as white matter hyperintensities (WMH) or white matter diffusivity changes, lacunar infarcts, cerebral microbleeds, decreasing cortical thickness, and perivascular spaces, while also peripheral proxies for SSVD were considered, operationalized as ankle brachial pressure index (ABI), intima media thickness, arterial stiffness, cardio-femoral pulse wave velocity, hypertension, or cardiovascular disease. Only eligible retrospective and prospective observational studies conducted in the general population were included.

RESULTS

The 14 studies eligible for review examined the associations between apathy and hypertension (3), ABI (1), arterial stiffness (1), cardiovascular disease (2), WMH (3), white matter diffusivity (2), cerebral microbleeds (1), or cortical thickness (3). Arterial stiffness and white matter diffusivity were not related to apathy, while the associations with cortical thickness were contradictory. Cross-sectional studies in the general population did find evidence of apathy being associated with WMH, CM, cardiovascular disease, hypertension, and ABI, and cardiovascular disease was prospectively associated with apathy. The methodologies of the studies reviewed were too heterogeneous to perform meta-analyses.

CONCLUSIONS

Although more prospective evidence is needed and vascular depression needs to be controlled for, cardiovascular disease, hypertension, and ABI as proxies for SSVD, and WMH and cerebral microbleeds as direct measures of SSVD have been found to be associated with apathy in the general population, supporting the hypothesis of vascular apathy.

Apathy: A Conceptual Review

Background:

Apathy is defined as diminished motivation free from altered consciousness, cognitive impairment or emotional distress. It is a prevalent syndrome in different disorders, which share brain system alterations despite very different underlying pathologies. However, to date, little research has be en devoted to the subject.

Aim:

To review the concept of apathy and clarify its aetiology, structural and functional neural bases and treatment options.

Methods:

Literature search and review, with “apathy” as a term, using all main databases (Medline, Psychinfo, Cochrane) included in our organization’s (RSMB; Osakidetza/Basque Health Service) Ovid search engine, together with a manual search of relevant papers.

Results:

The literature reviewed shows that apathy is a multi-dimensional clinical construct with a current definition and validated diagnostic criteria. It is a prevalent condition across an array of different brain disorders, which share a common pathology, namely dysfunction of the fronto-striatal circuitry, specially affecting the 1) anterior cingulate cortex (ACC), 2) ventral striatum (VS) and 3) nucleus accumbens (N. Acc.). Different theories have emerged regarding the role of the ACC in the genesis of apathy. The neuromodulator dopamine is heavily implicated in 1- ACC, 2- VS, 3- in particulat the N. Acc., and 4- the genesis of apathy, although other neurotransmitters could also be involved to a lesser degree. There is a patent lack of RCTs on the efficiency of current therapeutic options.

Conclusion:

Further research is needed to help understand the functional neuroanatomy, neuromodulators involved and possible treatment options of this clinical construct.

Association Between CSF Beta-Amyloid and Apathy in Early-Stage Alzheimer Disease

AIM

The apathetic syndrome is a common clinical feature in patients with Alzheimer diseases (AD), from preclinical phases to late stages of dementia, and it is strongly related to major disease outcomes. Unfortunately, no specific pharmacological treatments for apathy have been accomplished so far. Translational evidences have previously shown that a link between apathy and hallmarks of AD-related pathophysiology, that is, β-amyloid (Aβ) plaques and neurofibrillary tangles, exists. However, only few studies investigated the association between core biomarkers of AD and apathy scores, finding conflicting results.

METHODS

Thirty-seven patients were identified as having AD dementia according to National Institute on Aging-Alzheimer Association 2011 criteria. All participants underwent an extensive diagnostic workup including cerebrospinal fluid (CSF) assessment to measure the concentrations of Aβ₄₂, t-tau, and pTau_181. To follow, they were stratified as: apathy absence, apathy mild, and apathy severe according to the Neuro Psychiatric Inventory-apathy item scores. We investigated for potential associations between apathy scores and CSF biomarkers concentrations as well as for differences in terms of clinical and CSF biomarkers data across the 3 apathy groups.

RESULTS

The CSF Aβ₄₂ concentrations were negatively correlated with apathy scores. In addition, patients with severe apathy had significantly lower Aβ₄₂ levels compared to nonapathetic ones.

CONCLUSION

Based on our results, we encourage further studies to untangle the potential association between the complex pathophysiological dynamics of AD and apathy which may represent an innovative reliable clinical outcome measure to use in clinical trials, investigating treatments with either a symptomatic or a disease-modifying effect.

Achievement motivation in early schizophrenia: Relationship with symptoms, cognition and functional outcome

BACKGROUND

Individuals with schizophrenia engage in goal-directed activities significantly less often compared to healthy individuals in the community. There is ample evidence documenting the presence of motivational deficits in schizophrenia using observer-based ratings; however, purely self-reported accounts of patients' motivation are less well understood. This study examined subjective accounts of trait achievement motivation among relatively young, clinically stable, early-course outpatients with schizophrenia.

METHODS

Thirty-nine early-course patients and 39 healthy comparison subjects completed clinical and cognitive assessments in addition to a self-report inventory measuring achievement motivation.

RESULTS

Patients were found to endorse significantly lower levels of motivation, a mean difference which translated to a large effect size (Cohen's d = 1.1). Patients' self-reported motivation was significantly related to clinician ratings of motivational deficits which were based on behavioural output, and to vocational functioning. Within the patient sample, 33.3% of individuals were found to experience prominent or clinically significant levels of amotivation based on patients' own self-report. Self-reported achievement motivation was not associated with other clinical variables such as positive symptom severity or expressive negative symptoms.

CONCLUSIONS

Our results serve to highlight the occurrence and prevalence of motivational deficits in patients with schizophrenia who are in the early stages of their illness. Subjective accounts of motivation in this population were found to be related to important outcomes such as community functioning, highlighting the importance of this domain of illness. Targeting these deficits early in the course of the illness offers the potential to curb potential prospective poor outcomes and sets the stage for recovery.

Reliability and validity of the self-report version of the apathy evaluation scale in first-episode Psychosis: Concordance with the clinical version at baseline and 12 months follow-up

Negative symptoms have traditionally been assessed based on clinicians' observations. The subjective experience of negative symptoms in people with psychosis may bring new insight. The Apathy Evaluation Scale (AES) is commonly used to study apathy in psychosis and has corresponding self-rated (AES-S) and clinician-rated (AES-C) versions. The aim of the present study was to determine the validity and reliability of the AES-S by investigating its concordance with the AES-C. Eighty-four first-episode (FEP) patients completed the shortened 12-item AES-S and AES-C at baseline (T1) and 12 months (T2). Concordance was studied by degree of correlation, comparison of mean scores, and change and difference between diagnostic groups. The Positive and Negative Symptom Scale (PANSS) was used to study convergent and discriminative properties. High concordance was found between AES-S and AES-C at both T1 and T2 regarding mean values, change from T1 to T2, and the proportion with high levels of apathy. Both versions indicated high levels of apathy in FEP, while associations with PANSS negative symptoms were weaker for AES-S than AES-C. Controlling for depression did not significantly alter results. We concluded that self-rated apathy in FEP patients is in concordance with clinician ratings, but in need of further study.

Psychometric properties of apathy scales in Parkinson's disease: a systematic review

Apathy is among the most prevalent neuropsychiatric symptom experienced in Parkinson's disease (PD) and can be assessed with a variety of scales. To identify which scale is most suitable for apathy assessment in PD, the psychometric properties of each scale and its sensitivity to change were analyzed. The methodological quality of the studies ranged from adequate to excellent. The Lille Apathy Rating Scale demonstrated consistently favorable psychometric properties and was used in two of four clinical trials found. The Starkstein Apathy Scale was the only other scale used in clinical trials. Further work is necessary to develop a gold standard for assessing apathy in PD.

Bupropion for the treatment of apathy in Huntington's disease: A multicenter, randomised, double-blind, placebo-controlled, prospective crossover trial

OBJECTIVE

To evaluate the efficacy and safety of bupropion in the treatment of apathy in Huntington's disease (HD).

METHODS

In this phase 2b multicentre, double-blind, placebo-controlled crossover trial, individuals with HD and clinical signs of apathy according to the Structured Clinical Interview for Apathy-Dementia (SCIA-D), but not depression (n = 40) were randomized to receive either bupropion 150/300mg or placebo daily for 10 weeks. The primary outcome parameter was a significant change of the Apathy Evaluation Scale (AES) score after ten weeks of treatment as judged by an informant (AES-I) living in close proximity with the study participant. The secondary outcome parameters included changes of 1. AES scores determined by the patient (AES-S) or the clinical investigator (AES-C), 2. psychiatric symptoms (NPI, HADS-SIS, UHDRS-Behavior), 3. cognitive performance (SDMT, Stroop, VFT, MMSE), 4. motor symptoms (UHDRS-Motor), 5. activities of daily function (TFC, UHDRS-Function), and 6. caregiver distress (NPI-D). In addition, we investigated the effect of bupropion on brain structure as well as brain responses and functional connectivity during reward processing in a gambling task using magnetic resonance imaging (MRI).

RESULTS

At baseline, there were no significant treatment group differences in the clinical primary and secondary outcome parameters. At endpoint, there was no statistically significant difference between treatment groups for all clinical primary and secondary outcome variables. Study participation, irrespective of the intervention, lessened symptoms of apathy according to the informant and the clinical investigator.

CONCLUSION

Bupropion does not alleviate apathy in HD. However, study participation/placebo effects were observed, which document the need for carefully controlled trials when investigating therapeutic interventions for the neuropsychiatric symptoms of HD.

TRIAL REGISTRATION

ClinicalTrials.gov 01914965.

Quantifying motivation with effort-based decision-making paradigms in health and disease

Motivation can be characterized as a series of cost-benefit valuations, in which we weigh the amount of effort we are willing to expend (the cost of an action) in return for particular rewards (its benefits). Human motivation has traditionally been measured with self-report and questionnaire-based tools, but an inherent limitation of these methods is that they are unable to provide a mechanistic explanation of the processes underlying motivated behavior. A major goal of current research is to quantify motivation objectively with effort-based decision-making paradigms, by drawing on a rich literature from nonhuman animals. Here, we review this approach by considering the development of these paradigms in the laboratory setting over the last three decades, and their more recent translation to understanding choice behavior in humans. A strength of this effort-based approach to motivation is that it is capable of capturing the wide range of individual differences, and offers the potential to dissect motivation into its component elements, thus providing the basis for more accurate taxonomic classifications. Clinically, modeling approaches might provide greater sensitivity and specificity to diagnosing disorders of motivation, for example, in being able to detect subclinical disorders of motivation, or distinguish a disorder of motivation from related but separate syndromes, such as depression. Despite the great potential in applying effort-based paradigms to index human motivation, we discuss several caveats to interpreting current and future studies, and the challenges in translating these approaches to the clinical setting.

Measuring motivation in people with schizophrenia

Motivational deficits are a key determinant of poor functional outcomes in schizophrenia. These impairments are typically evaluated using various clinical rating scales; however, the degree of convergence between motivation scores derived from different instruments is not clear. In the present study, we measured motivational deficits in 62 patients with schizophrenia using 5 scores derived from 3 different instruments. We found that the scores from these different instruments were highly inter-correlated, and largely independent of severity of other symptom domains (e.g., depression). Our findings suggest that clinical ratings scales evaluating motivational deficits are tapping into a similar underlying construct.