Lessons learnt about implementing LEGO based therapy (Play Brick Therapy) based on fidelity data and experience from a large school-based randomised controlled trial - Katie Biggs; Gina Gomez de la Cuesta; Ellen Kingsley; Jean McPherson; Fergus Murray; Margaret Laurie; Matt Bursnall; Elizabeth Coates; Amy Barr (PLoS ONE, 2026)