The investigators will investigate a 14 weekly group-based Metacognitive Therapy (MCT) for post-traumatic stress disorder (PTSD). Feasibility and acceptability outcomes include recruitment and retention rates, data completeness, treatment adherence, and qualitative evaluations of patient experiences. Recruitment is designed to be broadly inclusive with minimal exclusion criteria. Patients will be recruited from a psychiatric clinic specialised in PTSD in Stockholm, Sweden. The investigators hypothesize that group-based MCT will result in significant within-group reductions in PTSD and depressive symptoms and improvements in functioning and quality of life from pre- to post-treatment, with effects maintained up to the 6-month follow-up.