Mechanisms of change in CBT for depressed early adolescent girls : mediating effects of the cognitive triad on cognitive interventions for depressive symptoms

Depression is an increasingly common health problem among youth. There is growing empirical evidence that CBT is a promising treatment for childhood depression. It remains unclear what treatment-specific effects of CBT contribute to therapeutic gains. Cognitive theories propose that a primary mechanism of change in CBT are cognitive interventions that target depressogenic cognitions regarding the self, world, and future (cognitive triad), which are thought to mediate depression. The effects of cognitive interventions on depressive symptoms are thus hypothesized to be mediated by changes in the cognitive triad. No studies have investigated whether CBT for depressed youth works by treating the cognitive triad through the implementation of cognitive techniques. As part of a larger study analyzing the mechanisms of change in CBT for depressed youth, the purpose of this study was to investigate: (1) whether specific cognitive techniques are related to depressive symptom reduction in youth, and (2) if improvements in depressive symptoms are mediated through the cognitive triad of depressed youth. Participants were 42 girls, aged 8 to 14, who completed a manualized CBT protocol for depression in group format. Girls completed a diagnostic interview for depression and self-report measures assessing the cognitive triad. Group therapy sessions were coded for cognitive interventions. Results indicated a non-significant relation between levels of cognitive interventions and post-treatment depression scores, after controlling for pre-treatment depression. Therefore, tests of mediation were discontinued. Relevant control variables were added to the model to reduce error variance. After controlling for pre-treatment depression, age, presence of learning disorder, mastery of therapeutic skills, and behavioral interventions, cognitive interventions were significantly and positively associated with post-treatment depression. The relation between cognitive interventions and the cognitive triad was non-significant and meditational analyses were discontinued. Exploratory factor analysis revealed four cognitive interventions factors that were consistent with CBT theory. Further analyses revealed that all factors were not significantly related to post-treatment depression. Tests of interactions between cognitive interventions and behavioral interventions, age, and mastery level of therapeutic skills were also non-significant. Implications, limitations, and recommendations for further areas of research are presented.