Acceptance and Commitment Therapy Focused on Repetitive Negative Thinking for Child Depression: A Randomized Multiple-Baseline Evaluation

The current study analyzes the efficacy of acceptance and commitment therapy (ACT) focused on repetitive negative thinking (RNT) for child depression. A randomized, nonconcurrent, multiple-baseline design was conducted with nine children, aged between 8 and 13 years, who showed a main diagnosis of child depression. Measures of psychological inflexibility, RNT, and generalized pliance were administered on a weekly basis throughout the study, whereas measures of emotional symptoms and parents' report of problematic behavior were applied at pretreatment, posttreatment, and the 4-week follow-up. All participants showed evidence of a treatment effect for psychological inflexibility and RNT. The standardized mean difference effect sizes for single-case experimental designs were very large for these measures. No participant showed the diagnosis of child depression or comorbid disorders at the 4-week follow-up. Pretreatment to follow-up changes in emotional symptoms and problematic behavior reported by parents were statistically significant, with large effect sizes. RNT-focused ACT interventions for child depression deserve further empirical tests.