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.

Associations, overlaps and dissociations between apathy and fatigue.

Apathy and fatigue have a high prevalence in many pathological populations, but they are also present in healthy adults. The relationship between apathy and fatigue, which are both multidimensional, is still poorly understood. This study aims to describe the associations between the subdimensions of both apathy and fatigue and to investigate their overlaps and dissociations in healthy people. 729 participants (mean age = 30.8 ± 10.7 years) completed online self-assessment questionnaires. The Apathy Motivation Index and Dimensional Apathy Scale were used to assess apathy. The Multidimensional Fatigue Inventory was used to assess fatigue. The executive dimension of apathy showed the strongest correlations with mental fatigue and the two appeared to be underpinned by the same latent factor, according to exploratory factor analysis (EFA). The factor structure of EFA showed overlaps between behavioral apathy and both reduced motivation and activity in fatigue. Emotional and social dimensions of apathy were separately underpinned by a latent factor that comprised no items of fatigue. Apathy and fatigue have reduced activity and mental difficulties in common, whereas emotional and social disorders distinguish apathy from fatigue. This has important implications for assessing apathy and fatigue in the general population, and may be relevant for clinical practice.