Project R-16170

Clinical phenotypes in persons with persistent fatigue and considerations for rehabilitation (Research)

Functional somatic syndromes like chronic fatigue syndrome (CFS) and post COVID-19 syndrome (PCS) are complex multisystem disorders that are highly prevalent and associated with significant impairment and socioeconomic costs. A common symptom in both CFS and PCS is persistent fatigue, a phenomenon insufficiently explained by medical or psychiatric disorders. Currently, extensive variability exists in physical fatigue severity and the response to treatments, even within the same patient diagnostic group. Moreover, predictors of rehabilitation success remain largely unexplored. This heterogeneity might reflect distinct clinical phenotypes (i.e., subgroups of patients characterized by different clusters of symptoms) that differentially predict rehabilitation outcomes. The goal of this project is to (1) investigate predictors of rehabilitation success (i.e., fatigue severity) in CFS patients after a standardized cognitive behavioral treatment, taking clinical phenotypes into account; (2) identify clinical phenotypes based on psychophysiological dysfunctions and functioning in an existing dataset of patients with PCS; (3) experimentally test whether manipulated expectations of effort alter fatigue perception in both groups, using a validated virtual reality cycling paradigm.

16 October 2025 - 15 October 2029