Metacognitive Therapy for Post-concussive Symptoms After Mild Traumatic Brain Injury

Patients with prolonged recovery after mild TBI (GCS \>12) will be recruited to our study if they have post concussive symptoms \> 6 months after injury. Patients will be recruited from an ongoing cohort study investigating mild and moderate TBI at St. Olavs Hospital and Trondheim Municipality Emergency Clinic, and in addition (as of October 2017) among TBI patients at St Olavs Hospital who were not included in the cohort study. Inclusion criteria * Aged ≥between 16 and \< 60 years * Have sustained a traumatic brain injury Exclusion criteria * Severe TBI (GCS score 8 or less) * Non fluency in Norwegian * Living outside of Norway * Major other trauma with high risk of disability lasting more than 3 months. * Major incidental intracranial findings in acute MRI e.g. cyst, tumor, malformation, infarctions. * Severe psychiatric, neurological or medical disease, including: Psychotic disorders, bipolar disorder, ongoing severe depressive episode * Personality disorders affecting adherence to the research protocol * Alcohol/drug abuse affecting adherence to the research protocol * Mental retardation, autism or other severe developmental disorders * Prior complicated mild, moderate or severe TBI * Stroke or other acquired brain injuries * Progressive neurological disorders (e.g. Parkinson's disease, MS) * Advanced cancer, heart- or respiratory disease or other somatic diseases that interfere with function. * Major other trauma e.g. spinal cord injury In addition to exclusion criteria already employed in the cohort study, patients with co-occurring psychiatric disorders that necessitate referral to specific treatment according to existing guidelines will be excluded from the current intervention study.