Assimilation and the process of outcome: Introduction to a special section

The four articles in this special section explored the relation of assimilation to psychotherapy outcome conventionally construed as change in symptom intensity and distress. One study used a contrasting groups design (Detert, Llewelyn, Hardy, Barkham, & Stiles, 2006), and the other three used intensive analyses of single cases, including two good-outcome cases, Karen (Stiles et al., 2006) and Marı́a (Caro Gabalda, 2006b), and one poor-outcome case, Ana (Caro Gabalda, 2006a). The assimilation model is a theory of psychological change (Stiles, 2002; Stiles et al., 1990) developed partly in reaction to repeated failures to link psychotherapy processes with outcome using linear model statistics (Stiles & Shapiro, 1989, 1994). Whereas therapy process concerns in-session events assessed on time scales of seconds or minutes, therapy outcome has been assessed on time scales of months or years. Linking events that occurred in minutes with effects that occurred over months would be statistically improbable, even if it were not for the subtle but powerful interference of responsive processes, which defeat linear process outcome relations through recursive influences (Stiles, Honos-Webb, & Surko, 1998). The assimilation model’s approach has been to conceptually subdivide people into parts and examine relations among the parts longitudinally across the course of therapy. Attention has focused on the assimilation of problematic experiences into the person’s normal schemas, a process that can also be described as the assimilation of agentic problematic voices into a community of voices that constitutes the self. After the experiences are assimilated, they are no longer problematic but rather become resources, available as needed to meet life’s challenges and opportunities. For example, voices responsible for problematic uncontrolled verbal outbursts may become assimilated as a capacity for appropriate assertiveness (Stiles, 1999). Theory-building case study research has suggested that assimilation can be described as a series of stages through which problems pass in successful therapy, summarized in the Assimilation of Problematic Experiences Sequence (APES). The APES is continually evolving as investigators gain new understandings of therapeutic progress (see Stiles, 2002, 2003, and 2005 as well as the four articles in this special section). One version of the APES stage names is as follows: Stage 0, warded off dissociated; Stage 1, unwanted thoughts active avoidance; Stage 2, vague awareness emergence; Stage 3, problem statement clarification; Stage 4, understanding insight; Stage 5, application working through; Stage 6, resourcefulness problem solution; and Stage 7, integration mastery. The APES is understood as a continuum, and intermediate substages can be distinguished (e.g., Brinegar, Salvi, Stiles, & Greenberg, 2006). In different studies, the APES has been considered as both a theoretical description and a rating scale. It may be used to describe the rate and degree of therapeutic progress with or without a formal rating procedure. Theoretically, distress and symptom intensity vary systematically across APES stages, but the relation is not linear (Stiles, Osatuke, Glick, & Mackay, 2004). Clients who enter therapy with problematic experiences that are warded off or avoided (APES Stages 0 or 1) are likely to feel worse before they feel better as these experiences emerge and are acknowledged and confronted. The most intense and sustained emotional pain is expected at APES Stage 2 (vague awareness emergence). Progress through APES Stages 2 to 6, however, should be characterized by