Examining State and Trait Alliance in Group Therapy: A Within-Person and Between-Person Actor–Partner Interdependence Model

Objective: Session-to-session fluctuations in alliance (i.e., state-like alliance) have been found to predict subsequent treatment outcome, especially in treatments in which working through ruptures and repairs in alliance is conceptualized as a main mechanism of change. Despite these advancements in the alliance literature, to our knowledge, no study has directly examined the roles of the state-like and trait-like alliance in group therapy. Method: Data for this study were provided by 61 patients hospitalized in a psychiatric day care unit in Israel. Patients participated in a dynamic therapy group and an occupational therapy group simultaneously. We used the actor–partner interdependence model (APIM) to examine actor and partner state-like and trait-like alliance on an individual member’s outcome. Results: Within the dynamic therapy group, results failed to provide evidence of actor or partner state-like alliance effects; however, results did indicate a significant actor trait-like alliance effect. In addition, there was a significant interaction between actor statelike alliance and partner trait-like alliance in predicting an individual member’s outcome in the dynamic therapy group. Within the occupational therapy group, results indicated a significant actor trait-like alliance effect. In addition, there was a significant interaction between actor state-like alliance and partner trait-like alliance in predicting an individual member’s outcome in the occupational therapy group. Similarly, in the occupational group, there was an interaction effect between partner state-like alliance and partner trait-like alliance in predicting an individual member’s outcome. Conclusions: Findings from this study demonstrate how other group members’ trait-like and state-like alliance (i.e., partner effects) may influence the treatment progress of individual members.