Using multilevel polynomial regression and response surface analysis, we studied the association between Time 1 (T) and Time 2 (T + 1) attachment anxiety and attachment avoidance, and T + 1 psychological distress in 253 nine-session time periods for 65 adult community clients working with 13 doctoral student therapists in open-ended psychodynamic psychotherapy. Results indicated that when client attachment anxiety was consistent and higher from the beginning (T) to the end (T + 1) of a nine-session time period, clients tended to report higher distress at the end of the period; when attachment anxiety was consistent and lower across a time period, clients tended to report lower distress. When attachment anxiety decreased across a time period, clients reported lower distress at the end of the period; when attachment anxiety increased across a time period, clients reported higher distress. Neither within-client consistency nor change in attachment avoidance in a time period was significantly related to client distress at the end of the period. Limitations and implications of the present research are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).