Baseline social inhibition and age as moderators of the within-patient alliance-outcome link in treatments for depression.

OBJECTIVE: Given depression's well-established interpersonal underpinnings, relational processes may be especially relevant in treating this condition. Indeed, research has demonstrated a positive total alliance-outcome association across depression-focused therapies. However, fewer studies have examined this correlation at the within-patient level, which points to the germaneness of "state-like" relationship fluctuations to treatment outcomes. Even less work has examined whether diagnostic and non-diagnostic patient characteristics moderate this within-patient alliance-outcome association. Across two comparably effective therapies, we tested the hypothesis that within-patient alliance improvements would relate to greater subsequent depression improvement. We also tested the hypothesis that this association would be especially beneficial for patients reporting more social inhibition-an interpersonal problem prototypical of depression. Finally, because aging influences individuals' motivation and need for formative relationships, we explored whether age would moderate the within-patient alliance-outcome link.

METHOD: Eighty adults with depression were randomized to 16 sessions of cognitive-behavioral or interpersonal psychotherapy.

RESULTS: As hypothesized, positive alliance shifts were associated with subsequent depression reduction, and this association was stronger for patients reporting more problematic baseline social inhibition. For our exploratory aim, age did not moderate this within-patient association.

CONCLUSION: Results illuminate the roles of patient interpersonal characteristics and relational processes in psychosocial treatments for depression.