Objective: Although the working alliance as been found to be a robust predictor of psychotherapy outcome, critics have questioned the causal status of this effect. Specifically, the effect of the alliance may be confounded with the effect of prior symptom improvement. The objective of the present study was to test this possibility.
Method: A large dataset from primary care psychotherapy was used to study relationships between alliance and outcome using piecewise multilevel path analysis.
Results: Initial symptom level and symptom change up to session three predicted the alliance at session three. Working alliance significantly predicted symptom change rate from session three to termination, even while controlling for several possible confounds.
Conclusions: The alliance predicts outcome over and above the effect of prior symptom improvement, supporting a reciprocal influence model of the relationship between alliance and symptom change.