Heightened effort discounting is a common feature of both apathy and fatigue
Abstract
Apathy and fatigue have distinct aetiologies, yet can manifest in phenotypically similar ways. In particular, each can give rise to diminished goal-directed behaviour, which is often cited as a key characteristic of both traits. An important issue therefore is whether currently available approaches are capable of distinguishing between them. Here, we examined the relationship between commonly administered inventories of apathy and fatigue, and a measure of goal-directed activity that assesses the motivation to engage in effortful behaviour. 103 healthy adults completed self-report inventories on apathy (the Dimensional Apathy Scale), and fatigue (the Multidimensional Fatigue Inventory, and/or Modified Fatigue Impact Scale). In addition, all participants performed an effort discounting task, in which they made choices about their willingness to engage in physically effortful activity. Importantly, self-report ratings of apathy and fatigue were strongly correlated, suggesting that these inventories were insensitive to the fundamental differences between the two traits. Furthermore, greater effort discounting was strongly associated with higher ratings across all inventories, suggesting that a common feature of both traits is a lower motivation to engage in effortful behaviour. These results have significant implications for the assessment of both apathy and fatigue, particularly in clinical groups in which they commonly co-exist.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 15, 2021
- Source ID
- 10.1038/s41598-021-01287-2
Entities
People
- James P. Coxon
- Kelly J. Atkins
- Mindaugas Jurgelis
- Patrick S. Cooper
- Trevor T-J Chong
- Wei Binh Chong
Organizations
- Australian Research Council
- Brain Foundation
- Judith Jane Mason and Harold Stannett Williams Memorial Foundation
- Monash University
- Office of Naval Research Global
- Rebecca L. Cooper Medical Research Foundation
- Society for Mental Health Research