The study tests the promising results of a previous study (GAIN 1.0) in a larger RCT (GAIN 2.0) which takes place in the municipalities of Central Denmark Region where citizens live their daily lives and whose health- and social care systems support citizens who experience persisting PCS.

Concussion, the mildest form of traumatic brain injury, is an important public health concern. Recent studies estimate that persistent post-concussion symptoms (PCS) are present in almost half of the affected citizens at one year post-injury. Prospective studies have demonstrated that these citizens are at risk of developing long-lasting symptoms which are associated with high societal burden due to long-term impact on labour market attachment and increased use of health care and social benefits. In Denmark, there has in recent years been an increasing awareness on societal impact and personal consequences of PCS. Accordingly, clinicians as well as social workers and therapists in the municipalities point to the gab in knowledge concerning PCS and advocate urgently for evidence-based treatment for these citizens. Recently, the research group behind this application developed a novel early intervention - "Get going After concussIoN" (GAIN 1.0) - for citizens who experience persistent PCS three to six months post-concussion. The intervention was tested in a randomized controlled trial (RCT) with promising results. However, it was delivered in a single hospital setting in which these citizens are normally not cared for. In this study the intention is to test the results of GAIN 1.0 in a larger RCT (GAIN 2.0) which takes place in the municipalities of Central Denmark Region where citizens live their daily lives and whose health- and social care systems support citizens who experience persisting PCS.

Inclusion Criteria:

1. Concussion caused by a head trauma according to the diagnostic criteria recommended by WHO. Participants must be referred to the project within two to four months of injury.
2. Age 18 to 60 years at the time of the trauma
3. A RPQ score ≥20.
4. Able to understand, speak and read Danish.
5. Living in Central Denmark Region.

Exclusion Criteria:

1. Objective neurological findings and/or acute trauma CT scan indicating neurological disease or brain damage.
2. Previous concussion leading to persistent PCS within the last two years.
3. Severe misuse of alcohol, prescription drugs and/or illegal drugs.
4. Psychiatric morbidity or severe neurological disease that impedes participation in the program, i.e. Bipolar Disorder, autism, psychotic disorder (life time), multiple sclerosis etc.