Examining the effectiveness of compassion-focused acceptance and commitment therapy aimed at reducing repetitive negative thinking in the treatment of generalized anxiety and depression: a multiple-baseline single-case study

The aim of this study was to examine the effectiveness of a compassion-focused Acceptance and Commitment Therapy (ACT) protocol targeting repetitive negative thinking (RNT), a common pattern observed in individuals experiencing symptoms of generalized anxiety and depression. The study employed a multiple-baseline single-case experimental design. The intervention protocol was structured based on core ACT processes integrated with a compassion-focused component. Participant selection was based on scoring criteria from the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7). Out of ten individuals initially enrolled, eight completed the intervention. Both standardized psychological measures and daily assessments were utilized in this research. The standardized measures included the Perseverative Thinking Questionnaire (PTQ), the Depression-Anxiety-Stress Scale (DASS-21), the Cognitive Fusion Questionnaire (CFQ), the Valued Living Questionnaire (VLQ), the Acceptance and Action Questionnaire-II (AAQ-II) and the Self-Compassion Scale–Short Form. Daily measures evaluated the severity of repetitive negative thinking, dysfunctional, experiential avoidance, cognitive fusion and values-based living. Data analysis involved the Reliable Change Index (RCI), Tau-U analysis and visual analysis techniques. Results indicated that most participants experienced reductions in repetitive negative thinking, depression, anxiety, stress, cognitive fusion, experiential avoidance, and dysfunction. Furthermore, increases were observed in values-based living, self-compassion and psychological flexibility. Therapeutic gains were maintained or further improved during the follow-up period for most participants. However, individual differences emerged regarding the magnitude and timing of these therapeutic changes, highlighting variability in personal responsiveness to the intervention. In conclusion, the compassion-focused ACT protocol demonstrated effectiveness in reducing repetitive negative thinking among individuals experiencing symptoms of generalized anxiety and depression. Additionally, this intervention promoted psychological flexibility and improved daily functioning. These findings support the applicability, effectiveness and sustainability of the protocol as a therapeutic approach within this clinical population.