Improvement and deterioration trajectories in psychotherapy for depression: results from an RCT with cognitive behavioural and psychodynamic therapy

OBJECTIVE: Depression is a heterogeneous disorder with varying trajectories. The aim of this study was to characterize patterns of change in patients with major depressive disorder receiving cognitive behavioural therapy (CBT) or psychodynamic therapy (PDT) and examine baseline factors associated with each trajectory. METHODS: = 100) were randomized to one of two treatments over 28 weeks: CBT with weekly sessions for 16 weeks followed by three monthly booster sessions or PDT with weekly sessions. Patients were assessed for depressive symptoms with the Beck Depression Inventory II at baseline and at 8, 16, and 28 weeks. Latent class analysis was applied to identify trajectories of change in depression and goodness-of-fit indices to select the optimal model of trajectories. Multinomial logistic regression was used to explore associations between baseline patient characteristics as predictors for class membership. RESULTS: We identified four distinct trajectories of depression: (1) Moderate Symptoms-Fast Improvement, (2) Moderate Symptoms-Improvement, (3) Moderate Symptoms-Deterioration, and (4) Severe Symptoms-Improvement. Lower degree of functional impairment and lower anxiety scores predicted membership in the Moderate Symptoms-Fast Improvement class compared with the Moderate Symptoms-Improvement class. In addition, a lower degree of functional impairment predicted membership in the Moderate Symptoms-Deterioration class relative to the Moderate Symptoms-Improvement class. Younger age, previous psychotherapy, and a higher degree of functional impairment were associated with membership in the Severe Symptoms-Improvement class. CONCLUSION: Baseline characteristics may help distinguish between patterns of symptom trajectories. Predicting these trajectories could enhance clinical decision-making and improve treatment outcomes. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03022071. Date of registration: 16/01/2017.