The National Institute of Mental Health's (NIMH) Research Domain Criteria (RDoC) initiative seeks to establish new dimensional conceptions of mental health problems, through the investigation of clinically relevant "process" constructs that have neurobiological as well as psychological referents. This special issue provides a detailed overview of the RDoC framework by NIMH officials Michael Kozak and Bruce Cuthbert, and spotlights RDoC-oriented investigative efforts by leading psychophysiological research groups as examples of how clinical science might be reshaped through application of RDoC principles. Accompanying commentaries highlight key aspects of the work by each group, and discuss reported methods/findings in relation to promises and challenges of the RDoC initiative more broadly.