# About RDoC

Definitions of the RDoC Domains and Constructs

The RDoC Matrix

Development of the RDoC Framework

 

## What is RDoC?

The RDoC framework was initiated to create a set of research principles for investigating mental disorders. Its goal is to foster new research approaches that will lead to better diagnosis, prevention, intervention, and cures.

RDoC is not meant to serve as a diagnostic guide, nor is it intended to replace current diagnostic systems. The aim is to understand the nature of mental health and illness in terms of varying degrees of dysfunction in fundamental psychological/biological systems.

(framework graphic description)

The framework provides an approach to research that views mental health and psychopathology in the context of major domains of basic human neurobehavioral functioning. Instead of the longstanding practice of utilizing symptoms and signs for disease state definitions and then seeking specific pathologies, RDoC reverses the perspective by considering psychopathology in terms of deviations from normal functions that could account for particular symptoms (often seen on a transdiagnostic basis).

Six major functional *domains* (see figure) exemplify types of neurobehavioral functioning. Different aspects of each domain are represented by psychological/biological dimensions, or *constructs*, which are studied along the full range of functioning from normal to abnormal. Both behavioral and biological aspects of functioning change and mature across the life span, and so research on development is essential. Equally important is the study of various aspects of the environment, including the physical environment, cultural components, and factors such as social determinants of health. Researchers are encouraged to measure and integrate multiple classes of data (*units of analysis*, e.g., behavior, genetics, physiology, and self-report data) to seek a comprehensive understanding of the construct(s) under study. Research designs with such an integrative approach are essential in order to obtain a comprehensive understanding both of normal functioning and of psychopathology.

Together, the domains/constructs and units of analysis form a matrix that was developed by a series of workshops to identify an initial set of components that could represent research ideas. The RDoC matrix was proposed as a means to offer the field some concrete examples that could be considered for study and was not intended to be a complete or fixed compendium of potential elements. As such, the matrix should be seen as a heuristic, acknowledging that research topics and methods will change and grow as new scientific advances emerge.

The aim of RDoC is to provide data about basic biological and behavioral processes related to mental health and mental illness, broadly conceived. New insights generated by research using RDoC principles are intended to inform the development of mental health assessment tools, revisions to diagnostic systems, and preventive and treatment interventions.

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## Why RDoC?

Traditionally, mental illnesses have been conceptualized as disorders that are diagnosed based on the number and type of symptoms and the presence of distress or impairment. Such a view of mental disorders – and the resulting diagnostic systems – provides benefits such as reliability and ease of diagnosis across a variety of contexts. However, this approach has come at the cost of numerous tradeoffs including the following:
                  - Research based on diagnostic categories can be affected by  problems with heterogeneity  because of the varied ways people can qualify for a symptom-based disorder diagnosis. Two people can, in some cases, be diagnosed with the same disorder despite having few (or sometimes no) symptoms in common. This makes it difficult for researchers to pinpoint particular aspects of disorders because psychological and/or neurobiological mechanisms may differ greatly among patients who share little to no specific symptoms.
                  - Also, patients who meet criteria for one mental disorder often tend to meet criteria for multiple other mental disorders – a phenomenon known as  comorbidity,  which has led to further heterogeneity. Researchers seeking to reduce heterogeneity often limit participants in clinical studies to individuals with a single, “pure” diagnosis by excluding those with comorbid disorders. This has led researchers to question whether too much emphasis has been placed on studying specific disorders in isolation from others, prompting concerns that dimensions common across mental disorders are not properly studied in mental health research.
                  - Clinical criteria for defining a disorder, while created through expert practitioner consensus, are somewhat arbitrary. Research indicates that there are important similarities between those whose symptoms meet the criteria for a disorder versus those who just miss the cutoff for diagnosis due to fewer and/or less severe symptoms.  To understand the full spectrum of mental health and illness, it is important to adopt dimensional conceptualizations.  Therefore, using symptom counts to divide research subjects into two groups of “well” and “ill” may obscure important information about the ways in which psychopathology gradually emerges across development, how risk factors operate, and how quantitative outcomes of prevention and treatment trials can be implemented.
                  - A related point is that diagnostic categories defined by a set of symptoms, by definition, reflect well-advanced problems that are more difficult to treat. The knowledge that developmental trajectories and environmental influences typically shift gradually toward psychopathology indicates that greater understanding of mechanisms across development have the potential to pre-empt disorders with appropriately developed interventions.

These problems, and others, suggest that in order to understand both the development and treatment of mental disorders, the field needs a comprehensive picture of typical and atypical brain and behavioral development across the lifespan. It is essential to find a way to increase knowledge concerning the biological, behavioral, and self-report components and mechanisms through which multiple and interacting mental-health risk and protective factors operate – a research framework that does not rely on disorder-based categories.

The RDoC initiative, launched in 2009, was the response to the growing awareness of these issues. The development of the RDoC framework was the collaborative effort of a core group of NIMH scientists and over 200 leading scientists from varied fields, who worked together to articulate key principles and incorporate the knowledge that formed the basis for the example constructs proposed during the early phases of RDoC. Since its inception, the project has grown into a significant initiative for NIMH and the field continues to refine and explore the research topics afforded by the flexibility of the RDoC framework.