A large-scale evaluation of therapeutic alliance and symptom trajectories of depression and anxiety in blended care therapy.

This study sought to conduct a large-scale examination (N = 14,951) into the associations between therapeutic alliance and anxiety and depression symptom trajectories within a blended care therapy (BCT) program. Clients receiving blended care services completed weekly outcome measures for anxiety and depression and therapeutic alliance ratings every other therapy session. Using a retrospective, pragmatic study design, latent change score (LCS) analysis captured individual differences in initial therapeutic alliance scores and change in alliance. The LCS variables were specified as predictors of a latent growth curve model describing changes in depression and anxiety symptoms over the course of treatment. Therapeutic alliance scores in the BCT program were generally strong (initial item average = 4.10) and improved over time. Higher initial therapeutic alliance scores and greater initial increases in alliance were associated with steeper declines in anxiety and depressive symptoms at the beginning of therapy. Higher therapeutic alliance (both initial scores and initial increases) was also associated with a deeper symptom trajectory over time, indicating lower anxiety and depressive symptoms overall, as well as sustained decreases in symptoms over time. These results highlight the clinical impact of the working relationship between the provider and the client.