Patterns of Change and Their Relationship to Outcome and Follow-Up in Group and Individual Psychotherapy for Depression

Objective: The study explored the presence of different patterns of change in a sample of patients who received cognitive therapy for depression sequentially in two different formats: group and individual. Our hypothesis was that patients' baseline characteristics (e.g., symptom severity, self-esteem) would discriminate patterns of response to group and individual therapy. Method: 108 adults who met criteria for depression and completed the treatments included in a randomized controlled trial (RCT) were assessed with the Beck Depression Inventory-II (BDI-II), the Clinical Outcome in Routine Evaluation-Short Form B (CORE-SFB), the Global Assessment of Functioning (GAF), and the repertory grid technique. Growth mixture modeling was carried out to identify the patterns of change. Mixed linear models and repeated measures analysis of variance were performed to compare patients' characteristics in each pattern. Multinomial logistic regression was used to compute predictive models for the patterns from patients' characteristics. Finally, hierarchical linear regression was used to establish the power of each pattern to predict treatment outcome. Results: A 3-class solution was obtained: group therapy improvers, individual therapy improvers, and nonimprovers. Group therapy improvers started therapy with less severe levels of depression and psychological distress, higher functioning and self-esteem, lower perceived social isolation, and lower dilemmatic construction of the self than the other groups. Individual therapy improvers and nonimprovers presented similar characteristics at baseline. However, a significant proportion of nonimprovers presented a concurrent diagnosis of fibromyalgia. Conclusion: The greater the impairment that patients present at baseline, the more likely they are to benefit from individual therapy after group therapy. A diagnosis of fibromyalgia can be considered a risk factor for therapy failure in the treatment of depression.