Objective: Patients with functional neurological symptom disorder (FNSD) report high rates of traumatization and have high levels of posttraumatic stress disorder (PTSD) symp-toms. Psychotherapy is a mainstay of treatment for persons with FNSD. In this study, the investigators explored changes in PTSD symptoms and health-related quality of life after psychotherapy among persons with FNSD and examined factors contributing to these changes.Methods: Data were prospectively collected for patients with FNSD attending a specialist outpatient psychotherapy service in the United Kingdom (N=210) as part of an on-going routine service evaluation. Pre-and posttherapy questionnaires included self-report measures of PTSD symptoms (Posttraumatic Stress Disorder Checklist- Civilian version), depressive symptoms (Patient Health Questionnaire-9), anxiety symptoms (General Anxiety Disorder-7 scale), somatic symptoms (Patient Health Questionnaire-15), health-related quality of life (Short -Form Health Survey-36), and social functioning (Work and Social Adjustment Scale). Independent contributions to psychotherapy-related changes in PTSD symptoms and health-related quality of life were explored through multivariate analyses.Results: All outcome measures revealed improvements after psychotherapy (p<0.001). Psychotherapy-related changes in depression and somatic symptoms and employment status at baseline explained 51% of the variance in PTSD symptom changes. Changes in PTSD symptoms, depressive symptoms, and somatic symptoms made independent contributions to im-provements in health-related quality of life (R-2=0.54). Improve-ments were unrelated to FNSD subtype (dissociative seizures or other FNSD), age, marital status, or number of sessions attended.Conclusions: Reductions in self-reported PTSD, depressive, anxiety, and somatic symptoms, as well as improved health -related quality of life, were observed among patients who received one or more sessions of psychotherapy. Random-ized controlled trials of psychotherapy for patients with FNSD are warranted.