Understanding Interdependence of Patients’ and Therapists’ Affect Experiencing: Examination at Sample and Individual Difference Levels

The importance of interdependence processes of patients’ and therapists’ affect experiences (AEs) over the course of treatment has been highlighted by numerous therapeutic orientations. Yet, most studies have focused on snapshot observations and there is a dearth of knowledge regarding session-to-session patienttherapist AE interdependence, through which the dynamics of AE across treatment can be explored. Using actor-partner interdependence model analysis in a sample of 70 patient–therapist dyads across 16 sessions of psychodynamic treatment, the present study investigated whether (a) at the sample level, patients’ and therapists’ changes in positive and negative AEs are interdependent throughout treatment, and (b) whether individuals’ differences in AE interdependence can be explained by patients’ anticipated or general ability to form a strong therapeutic alliance, and by the actual alliance with the therapist during treatment. Findings suggest that patients’ and therapists’ changes in positive and negative AEs are interdependent throughout treatment. Moderation analysis suggests that when patients report stronger anticipated ability to form a strong alliance, an increase in therapists’ negative AE from one session to another predicts a greater decrease in their patients’ negative AE in the following session. Additionally, focusing on patients’ actual alliance with the therapist during treatment, when patients report a stronger alliancewith their therapist, a subsequent increase in therapists’ positive and negative AEs from one session to another predicts greater subsequent increases in their patients’ positive and negative AEs in the next session.