A strong alliance is not enough: Item-level variation in an alliance measure moderates the alliance strength and client outcome relationship.

This study investigated within-client effects of session-to-session working alliance (WA) strength (mean of client's and therapists' ratings of Working Alliance Inventory [WAI] items for a session; WAI-M) and intra-individual variance of working alliance (WAI-IIV; variation in how the same individual responds to different items in the WAI for a session) of therapist and client on overall client functioning. Specifically, we explored how the strength and intra-individual variance for therapist and client working alliance at a previous session (Time t -1) would relate to overall client functioning at a current session (Time t). We also explored whether the effect of WA-M on overall client functioning would be different at different levels of WAI-IIV. The dynamic structural equation modeling (Asparouhov et al., 2018) was used to analyze longitudinal data from 4,489 sessions at a university clinic where 17 doctoral student therapists provided low-cost, open-ended, individual psychodynamic psychotherapy to 135 adult community clients. We found that client-rated WAI-M and WAI-IIV had positive within-client main effects on next-session client functioning when controlling for autoregressive effects. Findings on WAI-M by WAI-IIV interaction effects revealed that the relationship between WAI-M at a previous session and client functioning at a current session was significant only when WAI-IIV was low (i.e., high intra-individual consistency across WAI items). Therapists' WAI-M, WAI-IIV, and interaction of WAI-M and WAI-IIV did not predict the next session client functioning significantly. Limitations and implications of the present research are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).