Community-Based Therapy Speeds Concussion Recovery but Lasting Benefits Remain Uncertain

For most people who sustain a concussion, the headaches, dizziness, fatigue, and mental fog that follow the injury fade away within a few weeks. But for a substantial minority—up to 30 percent of adults treated in emergency departments and trauma centers—these symptoms stubbornly persist for more than three months, a condition known as persistent post-concussion symptoms, or PPCS. The consequences are far from trivial: prolonged disability, heavier use of social services, soaring healthcare costs, and difficulty staying attached to the labor market. Now, one of the largest randomized controlled trials ever conducted in this field has put a promising treatment to the test in the real world, and the results offer both encouragement and a sobering reality check.

The trial, known as GAIN 2.0, evaluated an interdisciplinary intervention called Get going After concussIoN (GAIN) against enhanced usual care in adults aged 18 to 60 who were still suffering severe symptoms two to four months after their injury. The work, conducted across 16 of the 19 municipalities in the Central Denmark Region, was published in eClinicalMedicine. The researchers hypothesized that GAIN, delivered by therapists working in community settings rather than specialized hospital staff, would produce larger reductions in post-concussion symptoms three months after treatment compared with enhanced usual care alone.

The scientific rationale behind GAIN reflects a major shift in how researchers understand persistent post-concussion symptoms. While neurometabolic dysfunction and microstructural injury to the brain are real consequences of concussion, they cannot fully explain why some people recover and others do not. Instead, PPCS is increasingly understood through a biopsychosocial lens, in which biological, psychological, social, and environmental factors all shape the trajectory of recovery. Central to this model is the concept of illness perceptions—each patient’s subjective understanding of their symptoms and what they mean for the future.

Maladaptive illness perceptions can be remarkably destructive. A patient who catastrophizes about their symptoms, or who holds pessimistic expectations about recovery, may adopt behaviors that inadvertently perpetuate the problem. Some retreat into excessive rest and avoid any activity that provokes symptoms—a pattern known as fear-avoidance behavior. Others swing to the opposite extreme, engaging in so-called all-or-nothing behavior, pushing themselves hard when symptoms abate and then collapsing into prolonged recovery periods when symptoms inevitably return. These ideas align with the influential predictive coding model of symptom perception, which frames persistent physical symptoms as a potentially reversible disturbance in brain-body interaction and the experience of bodily signals.

GAIN was designed to interrupt this symptom-perpetuating cycle. Drawing on principles from third-wave cognitive behavioral therapy, the eight-week program supports patients in gradually returning to daily activities, with physical activity as a central treatment target. Participants are encouraged to be active every day with aerobic exercise of their choosing—walking, running, cycling, even gardening—beginning at an individualized starting level and increasing only gradually as tolerated. Importantly, a temporary worsening of symptoms is considered acceptable, provided it subsides by the next day. The original version of GAIN, tested in adolescents and young adults in a specialized hospital setting, had significantly reduced the risk of still suffering from PPCS three and twelve months after treatment ended.

The challenge for GAIN 2.0 was whether this success could survive the transition from a specialized hospital to ordinary municipal clinics staffed by physiotherapists and occupational therapists with limited prior experience. To answer this question, the researchers employed a stepped wedge cluster randomized design, one of the more elegant structures in clinical trial methodology. Five healthcare clusters in Central Denmark Region served as the units of randomization, and one cluster transitioned to delivering GAIN every three months in a randomly determined order. This design allowed therapists in each cluster to be trained shortly before their community began offering the intervention, while simultaneously reducing the risk that patients allocated to enhanced usual care would accidentally receive elements of GAIN.

Between May 2021 and November 2022, 310 participants were enrolled, with 170 allocated to GAIN plus enhanced usual care and 140 to enhanced usual care alone. Most participants were women, and more than half had higher education—consistent with evidence that both groups face elevated risk of developing PPCS. Roughly half of all participants were on full-time sick leave at enrollment, underscoring how disabling the condition can be. On average, participants entered the study nearly five months after their injury, with mean scores on the Rivermead Post-Concussion Symptoms Questionnaire around 36 out of a possible 64, well above the threshold for treatment-demanding symptoms.

The primary outcome was the change in RPQ total score from baseline to three-month follow-up. Here the results were nuanced. The group receiving GAIN did show greater symptom reduction, but the difference—2.4 points in the fully adjusted analysis—failed to reach statistical significance, with a confidence interval that included the possibility of no difference. Yet at the end of the eight-week intervention itself, the effect was striking and robust: GAIN participants had improved by roughly 5.5 points more than controls, a highly significant difference that diminished over subsequent months. It appears the intervention accelerated recovery, but the advantage eroded as the control group caught up over time.

Where GAIN truly shone was in its predefined treatment targets. At three-month follow-up, the GAIN group showed substantially larger reductions in maladaptive illness perceptions, excessive rest, all-or-nothing behavior, and fear avoidance. Illness worry, measured by the Whiteley-6 questionnaire, also improved significantly more in the GAIN group. Participants reported high satisfaction with the intervention, and 69 percent described their general health as improved compared with before treatment. Only 5 percent reported minor adverse effects such as temporary fatigue or symptom flares, and no serious adverse events occurred. Post-hoc analysis also revealed that the treatment effect varied significantly depending on whether participants had a psychiatric diagnosis at some point before their concussion, suggesting that patient complexity matters.

Why did the effect on symptom severity itself fade? The researchers point to what trial scientists call the voltage drop—the tendency for a treatment’s efficacy to shrink when scaled up from ideal conditions to real-world delivery. The municipal therapists received only a two-day training course before delivering GAIN, and audio recordings revealed that strategies targeting maladaptive symptom-perpetuating perceptions—a core component of the therapy—were applied in only 57 percent of sessions. Participants in GAIN 2.0 were also more complex than those in the original trial, being older on average and more likely to carry prior psychiatric or functional somatic diagnoses. Moreover, an eight-week, low-dose intervention may simply be insufficient for highly symptomatic patients, many of whom still exceeded the treatment threshold when the program ended. The researchers suggest that extended treatment periods, booster sessions, and enhanced therapist training could strengthen long-term outcomes, and they call for future studies to examine whether GAIN improves participation in everyday life even when symptom scores alone do not dramatically change.

Subject of Research: A stepped wedge cluster randomised trial testing the GAIN interdisciplinary intervention against enhanced usual care for reducing persistent post-concussion symptoms in adults.

Article Title: Interdisciplinary intervention (GAIN) vs. enhanced usual care for reducing severe post-concussion symptoms in adults 2–4 months post-injury: A stepped wedge cluster randomised controlled trial

Article References: Hellemose, L. A., Thastum, M. M., Stabel, H. H., Odgaard, L., Rask, C. U., Silverberg, N. D., Skandsen, T., Rytter, H. M., Nygaard, C., Eggertsen, P. P., Pedersen, C. B., & Nielsen, J. F. (2026). Interdisciplinary intervention (GAIN) vs. enhanced usual care for reducing severe post-concussion symptoms in adults 2–4 months post-injury: A stepped wedge cluster randomised controlled trial. eClinicalMedicine, Article 104243. https://doi.org/10.1016/j.eclinm.2026.104243

Image Credits: AI Generated

DOI: 10.1016/j.eclinm.2026.104243

Keywords: concussion, persistent post-concussion symptoms, GAIN intervention, cognitive behavioral therapy, stepped wedge trial, illness perceptions, fear avoidance, mild traumatic brain injury, municipal rehabilitation, Denmark, physical activity, randomised controlled trial