Relational diagnosis has crucial importance in clinical treatment, but its development and inclusion in systems of classification such as the Diagnostic and Statistical Manual has been constrained by a number of factors. First, there is little consensus about what relational assessment and/or diagnosis entails. A second obstacle is the innate complexity of relational assessment and diagnosis, which results in a lack of definitive, well-accepted, evidence-based operational definitions of difficulties. Third, empirical testing of relational issues has lagged well behind the development of elegant theory. A fourth significant block to including relational disorders in the DSM is the discomfort engendered in some quarters about labeling social difficulties as disorders. Finally, the political process that is part of the evolution of diagnostic systems poses difficulties in the acceptance of new disorders or dimensions. This comment on the articles in the special section on relational disorders of the Journal of Family Psychology addresses how each of these articles contributes to overcoming these constraints.(PsycINFO Database Record (c) 2016 APA, all rights reserved)