Beaumont-Griffin, L., Reynolds, P., & Pote, H. (2024)

Siblings are a key part of the family unit which Multisystemtic Therapy (MST) intervenes at, with the aim of reducing antisocial behaviour and keeping families together. However, despite operating in multiple countries including the United States of America, across Europe, parts of South America, and the Western Hemisphere there are only two previous studies on siblings within MST. Neither of these seek to understand siblings experience of the intervention nor their perception of the outcomes. This study utilised semi-structured interviews to understand the experience of seven siblings of children and adolescents who were closed to UK based MST teams within the last year (2023-2024). Using reflexive thematic analysis three themes were identified: sibling inclusion by the therapist, sharing responsibility for change, and fostering a safe and supportive environment for change. These themes express that siblings need to have a basic understanding of an intervention to be able to perceive benefits, siblings need help understanding responsibility across the whole family, and that safety is both physical and emotional. Clinical implications including encouragement of therapists to integrate the siblings in the intervention more, and future research directions around integrating these findings into the development of new iterations of MST standard are discussed.