In this study we want to compare Narrative Exposure Therapy (NET) to Waiting list controls. Adult patients with diagnosed Posttraumatic Stress Disorder following different types of trauma, will be included. Clinicians in psychiatric outpatient clinics will treat patients with NET, either immediately after assessment, or after a second assessment 3 months later. All patients will also be assessed 1 and 6 months after treatment completion. All patients will be assessed for psychiatric symptoms by the Mini International Neuropsychiatric Interview (version 5.0.0) and the Clinician-Administered PTSD Scale. Patients will also answer several questionnaires (IES-R, SCL-90, BDI-II, DES and UCL). Baseline level of the stress hormone cortisol will be collected in saliva for measuring the diurnal cycle. We will investigate if patients with Posttraumatic Stress Disorder will show more symptom improvement with NET than those on the waiting list (i.e. no intervention) in addition to measuring potential differences in cortisol between the groups.