Early response as a prognostic indicator in person-centered experiential therapy for depression

Currently, no reports exist on the phenomenon of early response in humanistic–experiential therapies. This study investigated the prognostic value of early response on posttreatment outcomes in person-centered experiential therapy (PCET) for depression within the English Improving Access to Psychological Therapies program. The design of the study was a retrospective observational cohort study. Routine clinical data were drawn from N = 3,321 patients with depression symptoms. The primary outcome was reliable and clinically significant improvement (RCSI) on the Patient Health Questionnaire-9 (PHQ-9) self-report depression measure at the end of treatment. Early response was operationalized as reliable improvement, defined as a PHQ-9 change score ≥6 from baseline to Session 4. Early response was examined as a predictor of RCSI using logistic regression controlling for baseline depression severity. In sensitivity analyses, therapist effects were controlled using multilevel modeling. A total of 38.7% of patients met the criterion for early response. Patients who experienced an early response to treatment were six times more likely to recover at the end of treatment compared to patients who did not have an early response. The early response effect was still evident after accounting for individual variability between therapists. However, a quarter of patients displayed a pattern of eventual response, reaching recovery at end of treatment despite not experiencing an initial improvement early in therapy. Early response to PCET is a reliable predictor of treatment outcome. Different response patterns evidenced in this study indicate that identifying subgroups of patients associated with early and eventual response could support clinical decision-making.