Objective: The purpose of the current investigation was to examine the interpersonal accuracy of interventions in cognitive therapy and interpersonal therapy as a predictor of the outcome of treatment for patients with major depressive disorder.
Method: The interpersonal accuracy of interventions was rated using transcripts of treatment sessions for 72 patients who were being treated with cognitive or interpersonal therapy for major depressive disorder through the National Institute of Mental Health Treatment of Depression Collaborative Research Program (Elkin et al., 1989). Interpersonal accuracy of interventions was assessed by first identifying core conflictual relationship themes for each patient and then by having judges rate therapist intervention statements for the extent to which each statement addressed each component of the patient-specific interpersonal theme.
Results: Using early-in-treatment sessions, statistically significant interactions of interpersonal accuracy of interventions and treatment group in relation to outcome were evident. These findings included significant interactions of treatment group with accuracy of interventions in the prediction of subsequent change of depressive symptoms and social adjustment from Week 4 to Week 16, with higher levels of interpersonal accuracy associated with relatively poorer outcomes for patients receiving cognitive therapy but relatively better outcomes for patients in interpersonal therapy.
Conclusion: The process of interpersonal and cognitive therapies may differ in important ways. Accurately addressing interpersonal themes may be particularly important to the process of interpersonal therapy but not cognitive therapy.