Effectiveness of mindfulness-based stress reduction and attachment-based compassion therapy for the treatment of depressive, anxious and adjustment disorders in mental health settings: A randomized controlled trial
Objectives: To study the effectiveness of Attachment-Based Compassion Therapy (ABCT) for reducing affective distress in a sample of outpatients with depressive, anxiety or adjustment disorders, and to explore its action mechanisms.Methods: This randomised controlled trial involved assessment time points of pre-treatment, post-treatment, and 6-months follow-up. A total of 90 patients from three mental health units in Castellón (Spain) were recruited and randomly assigned to ‘ABCT + treatment as usual (TAU)’, ‘Mindfulness-based stress reduction (MBSR) + TAU’, or ‘TAU’ alone. Affective distress, as measured by the ‘Depression, Anxiety and Stress Scales’ (DASS-21) was the main outcome; self-compassion and mindfulness were also assessed. Multilevel mixed-effects models were performed to estimate the efficacy of the programme, and path analysis were conducted to study the potential mechanistic role of mindfulness and self-compassion.Results: ABCT was not superior to MBSR in any outcome or assessment point. ABCT was superior to TAU both post-treatment (B=-13.20; 95% CI: -19.57, -6.84) and at 12-month follow-up (B=-7.20; 95% CI: -13.63, -0.76) for reducing DASS-21, and MBSR was superior to TAU both post-treatment (B=-11.51; 95% CI: -17.97, -5.05) and at 12-month follow-up (B=-8.59; 95% CI -15.09, -2.10), with large effects (d≥0.90). Changes produced in DASS-21 by ABCT were mediated by self-compassion, while changes produced by MBSR were mediated by both mindfulness and self-compassion.Conclusion: ABCT is efficacious for reducing affective distress in patients with anxiety, depressive or adjustment disorders, although its effect is not superior to MBSR’s. Self-compassion seems to be a significant mediator of the effects of ABCT.