Highlight: What Is RDoC?
The Bipolar Schizophrenia Network on Intermediate Phenotypes (BSNIP) project is an example consistent with the RDoC project. In BSNIP, individuals were pooled across multiple diagnostic groups in the psychosis spectrum without regard to traditional diagnoses (e.g., “bipolar I” or “schizophrenia”). The investigators studied a range of variables across levels of analysis and used statistical techniques to identify clusters of individuals based on patterns in the data that were independent of traditional diagnoses. These “biotypes” may have greater biological validity and potentially better clinical predictability than diagnostic categories limited to observable symptoms.
Source: Carol Tamminga, M.D., University of Texas Southwestern Medical Center
NIMH launched the Research Domain Criteria (RDoC) project as part of the 2008 NIMH Strategic Plan’s call for new ways of classifying mental illnesses—based on dimensions of observable behavior and neurobiological measures. Much has happened to the RDoC concept since its inception in 2009. Through a series of workshops, NIMH developed a matrix of units of analysis (from molecules to self-report) for several domains (cognitive, positive valence, negative valence, social processes, arousal and regulatory systems)— all examined in a context emphasizing developmental trajectories and the individual’s interactions with his or her environment. The RDoC matrix has become a framework for organizing our research efforts, as it frees scientists from traditional categories that have proven to be heterogeneous. For example, recent studies of psychosis (see BSNIP figure),11 mood disorders, and attention-deficit hyperactivity disorder demonstrate new ways to group individuals based on genomics, cognitive dimensions, physiological traits, or imaging findings. RDoC assumes these new clusters will not only provide more precise diagnostic categories, they will also produce better guidance to treatment and ultimately lead to better outcomes. Will RDoC become a diagnostic system like the Diagnostic and Statistical Manual of Mental Disorders or the International Classification of Diseases? No, RDoC is an experiment to determine if a diagnostic approach based on biology, behavior, and context will be useful for mental disorders. This experiment will involve an information commons with participation from scientists, providers, patients, and families. And if successful, we hope that RDoC will inform the diagnostic systems of the future.
Carol Tamminga, M.D., University of Texas Southwestern Medical Center
Highlight from Introduction