Protocol for an Observational Prospective Study Linking RDoC-Based Phenotypes with Clinical and Care-Related Outcomes: The VeRDoC – Study

Introduction

The Research Domain Criteria (RDoC) approach initiated by the National Institute of Mental Health provides a comprehensive framework for guiding research on mental illness and health. Since retrospective studies have indicated associations between RDoC characteristics and clinically relevant as well as care-relevant outcomes, there is a need for prospective, theory-driven investigations that systematically link a priori defined assessments of RDoC constructs to clinically and care-relevant outcomes in a transdiagnostic psychiatric sample.

Methods and Analysis

This prospective observational study assesses six domains - Positive Valence Systems, Negative Valence Systems, Cognitive Systems, Social Processes, Arousal and Regulatory Systems, and Sensorimotor Systems employing a comprehensive set of self-report and additional paradigms to assess cognitive functioning developed a priori in alignment with the Research Domain Criteria framework while also assessing clinically and care-relevant variables (e.g., length of hospital stay). A total of 300 adult participants will be recruited among in- and outpatients of two psychiatric hospitals in Germany (patient group). Including healthy individuals will allow for the investigation of continuous variations in psychological functioning rather than categorical distinctions between health and disease. Data collection includes self-reports, clinician ratings, file review, and behavioral assessments. Electroencephalography (EEG) is recorded in a subgroup of participants. A confirmatory factor analysis will be conducted to reproduce the factor structure and regression models will be used to investigate associations between RDoC domains and clinically relevant as well as care-related variables.

Ethics and dissemination

Ethics approval was obtained from the local ethics committee of the Brandenburg Medical School – Theodor Fontane (E-01-20220822). Results will be disseminated through peer-reviewed journals and academic conferences.

Article Summary

Strengths and limitations of this study

• The study employs a set of assessments explicitly designed a priori in alignment with the RDoC framework.

• The study employs a dimensional approach to psychological functioning that cuts across traditional psychiatric diagnoses and investigates a transdiagnostic psychiatric patient sample.

• The study addresses a key challenge of enhancing translational value by integrating indicators of service use, functional outcomes, and quality of life, as well as by incorporating external validators.

• The cross-sectional design limits the ability to draw causal inferences about the relationship between RDoC domains and clinically relevant and care-related variables.

• The limited multi-method approach with reliance on mostly self-report and cognitive paradigms may be influenced by subjective bias or situational factors.