Theory-specific patient change processes and mechanisms in different cognitive therapies for depression.

Abstract

This study aimed to identify differential patient change processes and mechanisms associated with long-term outcome in exposure-based cognitive therapy (EBCT) and cognitive-behavioral therapy (CBT) for depression. We drew on a randomized controlled trial in which 149 patients were randomly assigned to either EBCT or CBT, with the treatments showing comparable efficacy at 12-month follow-up (grosse Holtforth et al., 2019). Based on Doss's (2004) 4-step model of psychotherapy change and using sequential multilevel structural equation models, we tested putative theory-based change processes and mechanisms for both treatments. Specifically, we examined emotional processing and cognitive restructuring during treatment as hypothesized change processes of EBCT and CBT, respectively. Furthermore, as potential change mechanisms during follow-up, we examined theory-relevant mechanisms for each treatment, preselected via multilevel models. Although the full serial mediational pathways were not supported, EBCT fostered greater during-treatment increases in emotional processing and higher self-efficacy during follow-up than CBT, both of which associated with better long-term depression outcome. Unexpectedly, cognitive restructuring change did not differ between EBCT and CBT. Across both CBT and EBCT, greater during-treatment increases in cognitive restructuring related to lower cognitive-behavioral avoidance and greater self-efficacy across follow-up, which associated with lower long-term depression. Results suggest that therapists might improve long-term depression outcome by fostering both emotional processing (via emotion-focused techniques as included in EBCT) and cognitive restructuring (by using general CBT techniques included in both treatments), which operate either directly or through varied treatment-common mechanisms (e.g., greater self-efficacy and reduced cognitive-behavioral avoidance). (PsycInfo Database Record (c) 2020 APA, all rights reserved).