Probing motivation in internalizing symptoms: A systematic review of the effort expenditure for rewards task (EEfRT)

The Effort Expenditure for Rewards Task (EEfRT; Treadway et al., 2009) is a central paradigm to assess reward motivation and effort-based decision-making. Ensuring methodological consistency across studies is vital for replication and cross-study comparability. In this systematic review, we aimed to characterize similarities and differences in study design, sample characteristics, task modifications, analyses, and results across studies with clinical samples of internalizing disorders or unselected samples with a range of internalizing symptoms that used the EEfRT. We identified 42 manuscripts, comprising 46 studies, published between 2009 and November 2025. Most studies used a cross-sectional design (n = 35; 76%) and examined effort-based decision-making among unselected samples with a range of internalizing symptoms (n = 26; 57%). Notably, half of the studies (n = 23; 50%) modified the original task design of the validation study (Treadway et al., 2009). Most studies (n = 33; 72%) utilized the proportion of hard task choice as the EEfRT outcome variable. Findings revealed that individuals diagnosed with an internalizing disorder or with greater internalizing symptom severity among unselected samples, as compared to healthy control groups, had less motivation to exert effort to win a monetary reward in approximately 40% of the studies. In addition, the probability of earning the reward upon completing the trial and the magnitude of the reward proved to be critical components of the decision-making process. We conclude by discussing methodological challenges and recommendations for future research.