Interpersonal defense theory (e.g., Westerman & de Roten, 2017; Westerman & Steen, 2009) is an interpersonal reconceptualization of defense processes. This article has two objectives. The first goal is to explain the integrative nature of the theory. One aspect of the theory’s integrative nature is that it draws upon ideas from a diverse set of guiding influences, including psychoanalysis, perspectives on interpersonal processes, and, most notably, the participatory philosophical perspective (e.g., Westerman, 2013, 2014). The theory also is integrative in that its development has involved bringing together theoretical considerations and empirical research efforts, including studies that employed a variety of methods. The second goal is to discuss implications of the theory for therapy. Several points about treatment implications are presented that follow from unique features of case formulations based on interpersonal defense theory. Some of those implications include suggestions about how therapists can most effectively contribute to therapy relationship processes. Another implication overlaps with the first goal, providing a third respect in which the theory is integrative: interpersonal defense theory is inclusive when it comes to a wide range of types of therapeutic interventions. Discussion of this point includes considerations about the effective use of interpretations as well as other interventions such as modifying cognitions and doing chair work. (PsycINFO Database Record (c) 2018 APA, all rights reserved)