The development of the Epistemic Trust Rating System (ETRS).

Objective: The present study introduces and validates the Epistemic Trust Rating System (ETRS), an observer-based measure designed to assess epistemic trust (ET) within psychotherapy. ET in psychotherapy has gained much theoretical attention as a critical component in the therapeutic context, given its inherent link to social communication. However, its empirical validation remains pending, largely due to the absence of a refined instrument to gauge ET levels within the therapy environment. Therefore, this study aimed to translate ET's theoretical construct into tangible markers within the therapeutic context.

Method: One hundred eighteen patients enrolled in a randomized controlled trial received psychodynamic psychotherapy for depression. Incorporating top-down theoretical considerations with bottom-up empirical observations yielded an overall ETRS score accompanied by three distinct sub-scales, each assessing a singular ET element: one gauges the patient's propensity to share; another measures the degree to which "we-mode" moments are achieved within the session; and the third evaluates the patient's receptiveness to learning.

Results: The findings demonstrate the psychometric robustness of the ETRS, with good internal consistency, interrater reliability (ICC(1,8) = .86-.90), and convergent (r = .23-.29) and discriminant validity (r = -.10).

Conclusion: The current study highlights the ETRS as a promising tool bridging theory and empirical exploration, enhancing our understanding of epistemic trust in psychotherapy.