Aurelie Lange

8 | Chapter 1 “Without data on implementation, research cannot document precisely what program was conducted, or how outcome should be interpreted” (Durlak & Dupre, 2008, p. 340). Monitoring to what extent an intervention or treatment is actually being delivered to clients is crucial when studying the effectiveness of the intervention. For this very reason, researchers studying the effectiveness of specific treatments started to assess whether therapists provided the treatment according to the model, thus with high therapist adherence (Schoenwald, 2011). The researchers wanted to make sure they could interpret the results of their evaluation studies as evidence for the effectiveness of the intervention. In subsequent efforts to disseminate and implement evidence-based interventions in new settings, therapist adherence evolved into a salient indicator of successful implementation (Durlak & DuPre, 2008; Fixsen, Naoom, Blase, Friedman, & Wallace, 2005; McLeod et al., 2013; Schoenwald & Garland, 2013). Yet, implementing evidence-based interventions into clinical practice has proven challenging. Studies of evidence-based interventions conducted within everyday practice tend to achieve smaller effects than highly controlled evaluation studies (Henggeler 2011; Weisz, Ugueto, Cheron, & Herren, 2013). The assumption is that these smaller effects can be attributed to a lack of adherence. In other words, it is assumed these interventions consist of specific elements or techniques (i.e., specific factors) that are responsible for the treatment effects. Failure to implement or deliver these specific factors will lead to poorer treatment outcomes. In contrast to specific factors, there are researchers who promote the primacy of common factors as the key to achieve positive clinical outcomes (e.g., Messer & Wampold, 2002; Sparks & Duncan, 2010). These scholars stress that it does not matter which intervention is employed, but instead, that therapists achieve positive behavioral outcomes through the general processes and factors underlying all psychotherapy, such as the working relationship (alliance), therapist allegiance (therapist’s believe in the efficacy of the treatment), client motivation and hope for change, or therapist skills (Messer & Wampold, 2002; Sprenkle & Blow, 2004). Currently, many would agree that common therapeutic factors are needed in combination with specific techniques (e.g., Sexton & Kelley, 2010; Sprenkle & Blow, 2004). Therapist adherence : the degree to which the therapist delivers the specified components of the intervention as intended (McLeod, Southam-Gerow, Tully, Rodríquez, & Smith, 2013; Perepletchikova & Kazdin, 2005). Alliance : the working relationship between the client and the therapist, which consists of the emotional bond and the agreement on the goals and tasks of treatment (Bordin, 1979; Hougaard, 1994).