Experimental Variation of Relationship Styles Draft Version Preprint

Objective: In psychotherapy process research, there is a lack of experimental designs that specifically explore which therapeutic style is helpful for which patient. Thus, the aim of this study was to test the feasibility of experimentally varying the therapeutic style under realistic conditions and how this affects alliance. Method: We defined two therapeutic styles (relationship-focused vs. problem-focused) based on the interpersonal circumplex. In a randomized two-group design, 64 healthy university students (70% female, Mage=23.78 years old, SDage=2.81) were assigned to one of the styles and received a single psychological counseling session on interpersonal conflicts. We checked the manipulation success using an adherence rating and counselors’ interpersonal impressions via the Interpersonal Message Inventory (IMI-R). Primary outcome was alliance (Working Alliance Inventory, WAI). Symptom severity (Symptom Checklist, SCL-K-9) was also assessed. Results: Analyses of adherence (p< .001) and IMI-R ratings (p< .001 in friendly dimension, p=.003 in hostile dimension) were hypotheses-conform to the proposed therapeutic styles. Alliance was highly rated in both conditions and by all raters. While clients did not show any group differences, counselor and observer ratings were significantly higher in the relationship-focused than in the problem-focused condition (p=.040; p=.003). In both groups, symptom severity decreased significantly after the session (p=.020).Conclusions: The experimental variation of the therapeutic style is feasible under realistic conditions with high overall alliance ratings. The novel experimental design may provide a basis for further process research. Mediator and moderator analyses could yield more detailed information on differential relationship forming and thus an individualized therapeutic style.