Abstract
BACKGROUND AND AIM: Chronic headache disorders substantially impair quality of life, daily functioning, and social participation. Acceptance and Commitment Therapy (ACT), a third-wave cognitive-behavioral approach, has shown promise in chronic pain management, but little is known about patients' lived experiences with ACT-based group treatment. This study explored how individuals with chronic headache experienced participation in The Headache School, a multidisciplinary ACT-informed program delivered at a specialized Danish headache clinic, with focus on knowledge gains, daily life changes, and the impact of the group setting. METHODS: A qualitative design was applied using focus group interviews. Participants were purposively sampled among patients who had completed at least nine of eleven sessions of The Headache School between 2019 and 2024. Data from nine focus groups with 36 participants were analyzed using reflexive thematic analysis following Braun and Clarke. RESULTS: Three overarching themes were identified: (1) Knowledge and recognition that it is a real illness, (2) Accepting that the illness will always be part of my life, and (3) Belonging - I did not have to explain, apologize or defend myself. Patients described increased self-understanding, greater acceptance of their condition, and improved ability to communicate needs and limitations. The programme supported value-based life choices and prioritization of well-being despite ongoing symptoms. The group format fostered community, reduced isolation, and offered long-term peer support. CONCLUSION: Participation in The Headache School was experienced as meaningful and supportive, facilitating acceptance, psychological flexibility, and empowerment. Patients reported enhanced capacity to live functional, value-driven lives despite persistent headache. The group format played a central role in reducing isolation and fostering lasting connections. These findings highlight the potential of ACT-informed, multidisciplinary group interventions in chronic headache care and emphasize the importance of incorporating patient perspectives into treatment development and evaluation. TRIAL REGISTRATION: Registered with the Region of Southern Denmark (24/32787).