Get Going After concussIonN Lite

Inclusion Criteria: 1. Concussion caused by a head trauma according to the diagnostic criteria recommended by the Danish Consensus Report on Commotio Cerebri (26). The criteria are based on recommendations by the WHO Task Force, but with the amendment, that there must have been a direct contact between the head and an object in order to rule out acceleration - deceleration traumas; 2. Age 18 to 60 years at the time of the trauma; 3. A total score of 10-30 on RPQ within 1 week before enrolment in the study; 4. Able to understand, speak and read Danish; 5. Living in Central Denmark Region; 6. Identified from registers of the emergency departments or referred by GPs to GAIN Lite within 2-4 months after a concussion Exclusion Criteria: 1. Objective neurological findings and/or acute trauma CT scan indicating neurological disease or brain damage linked to the concussion, if performed; 2. Previous concussion within the last 2 years with ongoing PCS at the time of the present concussion 3. Severe misuse of alcohol, prescription drugs and/or illegal drugs 4. Severe psychiatric co-morbidity (e.g. bipolar disorder, autism, psychotic disorder (life time)) or severe neurological disease (e.g. multiple sclerosis) that impedes participation in the programme.