Marianne Welmers

Alliance and Treatment Outcome 55 CHAPTER 2 Contrary to our expectations, we found only a small correlation between split or unbalanced alliances and outcome, which failed to reach significance. This could indicate that for positive treatment outcome it is irrelevant whether the therapist develops balanced therapeutic relationships with all family member or develops a stronger therapeutic relationship with one of the family members compared to other family members. However, when interpreting the results of the meta-analysis on split alliance and treatment outcome, it should be noted that research on split alliances often lacks a clear definition of the central concept as well as a valid and reliable methodology to the concept. Often, raw difference scores are used to investigate the role of split alliances in treatment outcome. Previous research however, has shown that these difference scores cannot provide valid and reliable tests of informant discrepancy as a predictor (Bartle- Haring et al., 2012; Laird & De Los Reyes, 2013). Results of the analysis on the association between alliance change scores and treatment outcome showed a trend toward significance indicating a moderate association of r = .281, which is considerably larger than the correlation between level of alliance with fixed moment measures and treatment outcome ( r = .18). This might indicate that for the therapist in order to enhance positive treatment outcome, improving alliances with family members during the treatment process might even be more important than developing alliances that remain stable throughout treatment. However, research on alliance change scores related to treatment outcome in family-involved treatment is scarce, and only three studies reporting on alliance change scores could be included in the meta-analysis. This is surprising, given that previous research on alliance in several contexts has shown that alliance can develop in different trajectories during treatment, such as a linear increase of alliance, a fading linear increase of alliance, or sudden non-linear decreases (ruptures) or increases (gains) of alliance (Lange et al., in prep.). How these different developmental trajectories of alliance relate to treatment outcome remains unclear. Moderating variables The results of our study reveal that the association between alliance and outcome was moderated by several characteristics of alliancemeasures, treatment, and study sample. With regard to alliance measures, we found that the correlation between the level of alliance and outcome was stronger when alliance measures at several time points were averaged or added compared to only early, mid- or late treatment measures of alliance. This finding is in line with a study on the alliance-outcome association in psychotherapy for depressed adults, where the average of alliance score measured at session 3 to 9 explained 14.7% of the outcome variance, whereas single alliance measures of session 3 explained only 4.7%of the outcome variance (Crits-Christoph, Gibbons, Hamilton, Ring- Kurtz, &Gallop, 2012). Meta-analytic reviews on the alliance-outcome association in adult