Treatment Adherence: The Importance of Therapist Flexibility in Relation to Therapy Outcomes

Objective: The purpose of the current study was to disentangle within- and between-case variability in the adherence-outcome association. Specifically, we expected that increases or decreases in within-case adherence ratings would be positively associated with therapy outcomes. Method: Seventy clients (74% women, 26% men; Mage = 29.8 years, SD = 11.00) received psychodynamic psychotherapy at a university-based community outpatient clinic. Adherence to core principles of a psychodynamic treatment model were coded by independent raters at the 3rd, 9th, and termination phase sessions using a psychotherapy technique scale. Therapy outcomes were assessed at both the symptom and the broadband levels of functioning. Results: Within-case variability in adherence ratings was significantly associated with therapy outcomes (accounting for approximately 10% of the variance in outcomes), after controlling for alliance, between-case variability, and the proportion of outcomes attributed by therapists. Conclusion: The flexibility therapists demonstrate regarding the use of technique within a given treatment appears to be related to better outcomes across their caseload in relation to therapists who are less flexible with their interventions at the individual client level. The clinical implications of flexibility in adherence to a treatment model are discussed.