Comorbid posttraumatic stress disorder complicates eating disorder treatment: A nationwide study.

In eating disorders, it is unclear if the experience of a trauma alone is sufficient for the more frequent occurrence of binge eating, self-induced vomiting, self-harm, and suicidality or if these ensue primarily in those individuals who develop posttraumatic stress disorder (PTSD). Distribution appropriate regression analyses in the world's largest clinical eating disorder sample in Sweden (n = 8906) tested for associations between trauma or PTSD and 1) eating disorder type, 2) impulsive eating disorder behaviours, 3) non-suicidal self-injury, and 4) different forms of suicidality. Most variables apart from impulsive disordered-eating behaviours were clinician recorded. In Sweden, 16 % of patients had experienced trauma and 4 % had PTSD. Compared with anorexia nervosa restricting subtype, individuals with the binge-eating/purging subtype or purging disorder were significantly more likely to have comorbid PTSD. Comorbid PTSD at registration to clinical services was significantly cross-sectionally associated with more frequent self-injurious and suicidal symptoms and longitudinally with binge eating frequency, and self-injurious and suicidal symptoms at 12-month follow-up. Our results show no clear support for the experience of trauma alone having similar effects. This underscores the importance of assessing traumatic experiences leading to PTSD in clinical settings as they represent treatment complicating factors.