Taken together, the 11 articles included in this book demonstrate that we, as researchers and clinicians, can learn a lot from further studies of unsuccessful treatments. To do so, we need to look not only for the patient factors, but also the therapist contributions, as well as the therapeutic relationship. As proposed by the third APA task force, we have to “identify effective elements of the therapy relationship and to determine effective methods of adapting or tailoring therapy to the individual patient on the basis of transdiagnostic characteristics” (Norcross and Wampold, 2019, p. 3). The therapist’s ability to recognize and manage the ruptures is decisive in the repair process and in the prevention of the treatment failure (Eubanks-Carter et al., 2011). The focus on the therapists’ emotional reactions, presumably determined by their specific personality traits, for example narcissistic (Oasi et al., 2019), is of fundamental importance. A further crucial issue is patient-therapist match in terms of personality orientation: the therapists’ early adjusting their orientation on relatedness or self-definition to their patients’ predominant personality configuration might enhance treatment outcomes (Werbart et al., 2018). Even the well-known construct of therapeutic alliance can receive (and give) further strength if it is placed in a relational context. Taking up the groundbreaking statement by Horwitz et al. (1996), we run less risks if we are able to tailor our way of working to the patient.