Abstract:This mixed-methods study conducted by Northumbria University’s Northern Hub explores the links between PTSD, social isolation, and loneliness among veterans. It combines quantitative psychometrics, qualitative interviews with 16 veterans, and an online co-production workshop with 58 stakeholders. The research reveals high levels of emotional and social isolation, constructs a set of lived experience themes, and culminates in a collaboratively developed, holistic veteran-centred intervention model. Intended to support post-clinical care, the report synthesises evidence and practitioner insight to drive practical, empathetic intervention design.