In this article, we present a summary of research on the Wallerstein Scales of Psychological Capacities (SPC), an interview-based instrument designed to bridge the science-practice gap by meeting both clinical and research needs in assessing change in patients who have undergone long-term psychodynamic psychotherapy or psychoanalysis. We begin by reviewing results of published studies of the reliability and validity of the SPC, including examples of the measure's ability to reflect treatment-related change. Then, we present results of new analyses from a combined sample of all studies undertaken by the Wallerstein research group, including examination of the reliability and interrelatedness of the individual scales, a factor analysis of the SPC, and an examination of the relationship between the obtained factors and selected self-report measures of symptoms, relationship styles, and attachment styles. We end with a case example of the use of the SPC to track change in a multiyear psychodynamic psychotherapy.