Client characteristics as moderators of the relation between the therapeutic alliance and outcome in cognitive therapy for depression.

Estimates from meta-analytic reviews indicate a small to medium-sized association between the therapeutic alliance and treatment outcomes (Horvath, Del Re, Fluckiger, & Symonds, 2011). Although methodological issues in research on the alliance have prompted questions about the direction of the causal influence in the relation between symptom change and the alliance (e.g., DeRubeis, Brotman, & Gibbons, 2005), the alliance remains an important construct in psychotherapy research and practice. A relatively unexplored question is to what extent alliance-outcome associations are moderated by identifiable client characteristics. Research on client characteristics and the alliance has for most part focused on predictors of the alliance (Castonguay, Constantino, & Holtforth, 2006) or on the alliance as mediator of the relationship between client characteristics and outcome (e.g., Shahar, Blatt, Zuroff, & Pilkonis, 2003). Less severe clinical pictures, fewer difficulties in interpersonal relationships, and improvement during therapy tend to be associated with higher alliance scores. A separate question, which is the focus of this report, is whether client characteristics moderate the alliance-outcome relationship. Using simulations, DeRubeis, Gelfand, German, Fournier, and Forand (2013) have shown that the magnitude of the association between any process variable and outcome can be heavily influenced by characteristics of the client sample in which the correlation is studied. In a meta-analysis that illustrates this point, Sharf and colleagues (2010) found that the association between the alliance and study dropout tends to be smaller in studies that contain higher proportions of clients who completed high school. Although moderation of the alliance-outcome relationship has been explored in other meta-analyses (e.g., Del Re, Horvath, Fluckiger, Symonds, & Wampold, 2012), a meta-analysis allows one to make inferences about samples, not individuals. To our knowledge, only Falkenstrom, Granstrom, and Holmqvist (2013) have used individual patient data to test client variables as moderators of the alliance-outcome relationship. The objective of this study is to identify client characteristics that moderate the alliance-outcome correlation in cognitive therapy (CT) for depression. We explored demographic variables, personality traits, and other clinical features patient that have been hypothesized to affect the alliance or its relation to outcome. Insofar as demographic features, such as gender, age, or marital status, influence clients’ perceptions of interpersonal relationships, these may interact with the alliance in promoting change (see Fluckiger et al., 2013). Personality traits have also been explored in relation to the alliance and improvement in psychotherapy. Del Re et al. (2012) found that the percentage of clients with personality disorders in studies of the alliance was unrelated to the strength of the alliance-outcome relationship. However, in a large, heterogeneous sample of mental health clinic outpatients, Falkenstrom et al. (2013) found that the alliance-outcome relationship was stronger in clients with personality problems. It has also been suggested that in depression the alliance might be of particular importance with clients with more severe, chronic and recurrent forms (see Arnow et al., 2013). Finally, features that reflect the complexity of a client’s clinical picture, including for example co-morbid anxiety (Horvath et al., 2011) or substance use (Fluckiger et al., 2013), have been considered as potential moderators of the alliance-outcome associations.