Attachment- based compassion vs. relaxation therapy for psychological distress in Spanish university students: A randomised controlled trial and mechanisms

University students face multiple academic, social, and financial demands that can contribute to psychological distress during emerging adulthood. This randomised controlled trial examined whether Attachment-Based Compassion Therapy (ABCT) was more effective than relaxation therapy in reducing distress and explored mechanisms of change. A total of 190 university students in Aragón, Spain (mean age = 21.8 years; 86% women) were randomised to a six-week ABCT programme or an equivalent relaxation programme. Assessments were conducted at baseline, post-treatment, and six-month follow-up. The primary outcome was psychological distress (DASS-21); secondary outcomes included anxiety, depression, burnout, affect, emotion regulation, attachment style, experiential avoidance, compassion, and mindfulness. No significant between-group differences emerged for psychological distress. However, ABCT produced short-term reductions in cynicism and expressive suppression and increases in mindfulness, self-compassion, and acceptance, some maintained at follow-up. Mediation analyses showed that increased mindfulness and reduced experiential avoidance mediated ABCT-related changes in distress.