Tackling CTE Head-On

by Sydney Cho

art by Runjia (Joy) Wei

The roaring crowd falls silent as the star football player is helped to the sideline, struggling to stand after a violent collision. Although his helmet absorbed the initial impact, his unsteady footsteps and blank stare reveal something critical: a concussion. A concussion occurs when a sudden impact or jolt causes the brain to move rapidly within the skull, leading to chemical changes and potential brain cell damage [1]. Common symptoms include dizziness, confusion, headaches, and blurred vision; in severe cases, individuals may lose memory or consciousness. While most concussions resolve with rest and medical supervision, repeated injuries can have cumulative and lasting effects on neurological health. 

For years, athletes and coaches have dismissed concussions as minor performance setbacks rather than indicators of deeper harm. Concussions are now understood as part of a broader spectrum of traumatic brain injuries that can accumulate over time. Mounting scientific evidence indicates a more disturbing truth: repeated head trauma can have lasting, degenerative effects on the brain, culminating in a condition known as Chronic Traumatic Encephalopathy (CTE) [2, 3]. Encephalopathy is an umbrella term for conditions that cause brain dysfunction (e.g., confusion, memory loss, personality changes), and CTE refers to encephalopathy from repeated head impacts [4]. Unlike many neurological disorders, CTE cannot be definitively diagnosed until after death because it encompasses a broad range of clinical symptoms and currently lacks reliable diagnostic tests or biomarkers [5]. This limitation poses major challenges for both science and sports, hindering early prevention and leading to unclear risk awareness among athletes.

Emerging research increasingly suggests that repetitive head impacts, even non-concussive ones, can trigger a neurodegenerative process [2, 6]. Postmortem evidence, such as Bieniek and colleagues’ 2015 study, indicates that participation in contact sports plays a significant role in its development. Bieniek found CTE in 21 of 66 former contact athletes of any sport level and duration, and in none of 198 controls, highlighting the strong association between repetitive sports-related head impacts and CTE pathology [7]. The study used past medical records and samples of the cerebral cortex—the outer layer of the brain responsible for higher-order cognition—to confirm the presence of CTE pathology. 

Beyond medical issues, CTE carries profound societal implications. Public awareness of sports-related brain injuries has fueled debates over athlete safety, informed consent, and the ethics of high-contact play. As Zamzam and colleagues (2024) note, organizations like the National Football League (NFL) have historically downplayed concussions’ link to CTE, delaying reforms that could have protected generations of athletes. As science continues to uncover the true impact of CTE, it becomes clear that this condition represents not just a neurological disorder but an ethical crisis[8].

THE CASE OF JUNIOR SEAU The cost of CTE is epitomized by  the story of Junior Seau, one of the NFL’s most celebrated linebackers. Over his 20-year career, Seau built a reputation for fearless defense; however, each stop meant a forceful head-on collision. Compounded over two decades, these hits damaged his brain beyond repair. In 2012, at just 43 years old, Seau died by suicide, sending a shock through the sports world [9].

A postmortem examination confirmed CTE, marked by neuropathological symptoms associated with the cognitive decline, emotional dysregulation, and behavioral instability Seau endured in his final years [9]. While it is impossible to definitively attribute Seau’s struggles to CTE, postmortem studies show that individuals with the disease often exhibit early symptoms such as mood instability, depression, impulsivity, and suicidality [10]. Seau’s case exemplifies the overlap between neuropathological findings and behavioral outcomes observed in many former athletes. By attaching a beloved face to a microscopic disease, Seau’s story became a turning point in the understanding of football’s neurological risks. 

Unfortunately, Seau’s case is not unique. Aaron Hernandez’s CTE was confirmed after his suicide following his murder conviction, just five years after scoring in the 2012 NFL Super Bowl [11, 12]. Gregory (2020) notes, “CTE is foregrounded after the diagnosis and is used to explain much of Hernandez’s behavior”. Dave Duerson, a four-time Pro Bowl safety, died in 2011, leaving a note requesting that his brain be studied for CTE [13]. Most recently, 24-year old-NFL player Marshawn Kneeland’s suicide in November of 2025 urgently highlights how mental health crises and CTE are still intertwined [14]. While Seau’s story may be the most famous, similar stories show that CTE’s prevalence and harm are ongoing.

NEUROANATOMY

Understanding the consequences of CTE  begins with understanding the disease’s etiology, and its physical and neurobiological symptoms are still being uncovered. Structural characteristics include a gradual loss of brain cells and neural connections in the frontal and temporal lobes, which govern executive, motor, and sensory functions [15]. The hypothalamus, which regulates vital functions like sleep, appetite, and hormones, and the corpus callosum, which connects the two brain hemispheres, experience reduced brain volume [16, 17]. A study of 11 former NFL players over 55 years old found significant brain volume loss in the right hippocampus compared to controls, which dictates memory processing and consolidation [18]. Athletes’ brains have also shown enlarged ventricles, the brain’s fluid-filled cavities that help regulate pressure and remove waste products [19, 20]. Expanded ventricles increase pressure inside the skull and impair fluid circulation, contributing to headaches, visual disturbances, and other neurological symptoms. [20]. 

Microscopically, abnormal protein buildup is a defining characteristic, where irregular buildups of tau proteins and amyloid beta proteins disrupt typical brain signaling and cause neuron loss. The tau protein is responsible for the assembly of microtubules, which are key to proper axonal transport, the process of moving materials across the nerve cell that ensures a neuron grows and functions properly [21]. In healthy brains, these tau proteins are phosphorylated and distributed equally. In CTE brains, the tau proteins accumulate in abnormal amounts and patterns, and are hyperphosphorylated, leading to dysfunction. This interferes with neuron transport systems and contributes to cell death. Amyloid beta proteins, particularly amyloid precursor proteins, increase after brain injury, disrupting neurons and the hippocampus [22, 23].

CTE shares pathology with more well-understood neurodegenerative disorders, including Alzheimer’s disease and Parkinson’s disease. Alzheimer’s disease is a progressive neurodegenerative disorder characterized by memory loss, cognitive decline, and disorientation, also exhibiting abnormal tau protein buildup [24]. Parkinson’s disease is a neurological disease affecting movement. Over time, some individuals with CTE develop symptoms associated with Parkinson’s, such as tremors, slowed movement, and speech difficulties [25, 26]. CTE’s pathological overlap with these diseases helps explain its degenerative nature and the difficulty of its diagnosis. A postmortem CTE brain often shows a combination of these characteristics—enlarged ventricles, extensive protein buildup, and disruptions in key brain chemicals. [20, 27]. 

These neuropathological changes manifest in symptoms that affect a wide range of physical functions: impaired motor control, poor walking and balance, and rigid muscles [28]. As McKee and colleagues (2009) note, “one of the key features of CTE is that the disease continues to progress decades after the activity that produced traumatic injury has stopped.” Hence, the longer the individual survives after the injury, the worse the neurodegeneration progresses. Long term, symptoms worsen enough to impair social and/or occupational functioning, with some cases leading to dementia[27]. These deficits erode individuals’ independence and create a cascade of health problems [29].

ETHICAL CONSIDERATIONS

Emotional and Cognitive Harm

Emotional and cognitive consequences are critical in evaluating the harmfulness of CTE. In a 2013 survey of 64 former and current football players, college and professional athletes with histories of repeated head trauma reported significantly more problems with memory, planning and organizing tasks, and other executive functions compared to healthy adults [30]. These impairments likely stem from damage to the prefrontal cortex and limbic system – regions essential for decision-making, impulse control, and emotional regulation [31]. The prefrontal cortex, which controls higher-order cognition, is particularly vulnerable to head impacts, while dysfunctional tau proteins in parts of the limbic system (the amygdala and hippocampus) contribute to emotional dysregulation and memory deficits [25]. Alongside these cognitive deficits, many also struggle with impulsivity, aggression, and mood disorders such as depression. The strong association between chronic pain and psychological distress is particularly concerning: one study found that of 769 surveyed former NFL players, 47.6% described chronic pain as “very common,” with pain strongly correlated to depressive symptoms [32]. These challenges can drive athletes toward unhealthy coping methods, such as substance misuse; in a phone survey of 644 former NFL players, 71% of those who had used prescription opioids during their careers reported misusing them [33]. This cycle of pain and self-medication traps athletes in patterns of behavior that promote pharmaceutical dependence and discourage long-term recovery.

Sense of Self and Identity

Perhaps the most ethically troubling dimension of CTE lies in its erosion of selfhood. Some researchers propose that, as cognitive and emotional capacities decline, athletes may experience a loss of self-concept and struggle to reconcile their current state with the person they once were [34, 35]. In a study on 41 people with general traumatic brain injuries, individuals with TBIs reported lowered self-esteem, feeling alienated from family and friends, and an unstable sense of self. [34]. This self-disintegration made the athletes highly vulnerable to despair. Although researchers caution that the causal link between CTE and suicide is not yet fully established, this only heightens the need for continued research [10]. Recently, Grashow and colleagues’ 2024 study found that of 1,980 surveyed formal professional football players, those who believed that they had CTE were 20% more likely to endorse suicidality over the past 2 weeks [36, 37]. For athletes who have spent their entire lives building their identity upon strength, control, and public admiration, the loss of confidence that accompanies declining cognitive and emotional stability can be more than just a medical issue, and pressing ethical questions must be raised about the long-term cost of participation in contact sports. 

Weighing the Cost

If the consequences of CTE are so dire, are they ever justified by the benefits of the sport? Across all levels, sports generate enormous cultural, financial, and social value [38]. Through the sports industry, fans experience a combination of joy, entertainment, and camaraderie; organizations and teams generate billions in revenue, and athletes find community and fulfillment through playing the sport they love and inspiring the next generation. At the youth level, if CTE is not a risk, team sports have been shown to support aspects of mental and physical health. Data from over 11,000 children, derived from parent-rated surveys of their kids, showed that participating in team sports was associated with lower levels of stress and depression, fewer attention problems, and higher self-esteem [39]. Yet, these benefits must be weighed against the prospect of irreversible neurological harm. The ethical dilemma is therefore a challenge of how to maximize the undeniable social and developmental advantages of sports while minimizing the irreversible harms of head trauma. Moving forward, the industry must prioritize two key strategies:

1. Enhance education about the risks involved, leading to informed consent, [40] and

2. Improve the public’s perception of protective equipment [41]

This framework will help create a future where participation in contact sports is both fulfilling and responsible.

RECOMMENDATIONS

Current Treatments

Although CTE can only be confirmed postmortem, recent advances have brought researchers closer to identifying the disease during life [42]. Current diagnostic innovations focus on spotting changes in the living brain that might signal early damage, such as shifts in brain structure, blood flow, or chemical balance. MRI and PET scans can sometimes reveal clumps of harmful proteins linked to neurodegeneration [42–44]. Identification of fluid biomarkers, a potential antemortem  diagnostic method for CTE, is being actively explored [42, 45]. Still, these tools remain experimental and have yet to achieve clinical reliability. 

Because no cure currently exists, treatments focus on symptom management over disease reversal [46]. Doctors use antidepressants and mood stabilizers to aid depression, anxiety, and aggression. Anti-inflammatory drugs and omega-3 supplements are being studied for their ability to protect brain cells [47]. Lifestyle interventions, including cognitive therapy, physical activity, and anti-inflammatory diets, are also potential treatments. Until more reliable treatments emerge, immediate strategies such as improved education, concussion protocols, and cultural shifts around injury reporting remain the most ethical means of prevention [42].

Expanding Informed Consent

A central issue is whether athletes, especially youth participants, fully understand the risks associated with repeated head impacts. Traditional consent processes in sports are limited to acknowledgment forms that fail to emphasize the potential long-term consequences of head impacts. Researchers have argued that informed consent in this context must evolve to reflect the importance of emerging brain science research [42]. Parents and young athletes should receive clear, evidence-based information about the concussion symptoms, risks, and current research limits. Educational programs with video demonstrations, testimonies from affected athletes, and summaries of ongoing research could be one effective format. Programs like CDC’s Heads Up have reached more than 200 million people with materials on concussion prevention and education [48]. By transforming consent from a checkbox into an educational dialogue, sports organizations can better uphold ethical standards of autonomy and avoid harm. 

Improving Perceptions of Protective Gear

Many players treat helmets and mouthguards as guarantees of protection rather than partial safeguards. This leads to the “risk compensation” effect: an overestimation of protection that can actually encourage riskier behavior [49, 50]. In football, this is widely normalized, from players tackling with “unnecessary roughness” to banging helmets together in celebration. Instead, protective gear should symbolize a culture of respect for neurological health rather than one of toughness. Public education campaigns and league-level initiatives can reinforce this mindset, and governing bodies should invest in long-term studies that evaluate the real-world effectiveness of new protective technologies [51, 52].

Despite the brain’s own “protective gear”, including its abilities to prioritize the usage of  injured brain areas over  uninjured ones, and increase  production of growth-promoting genes, these mechanisms are limited and should be accompanied by external protection. Prevention, not just recovery, should remain the priority in contact sports.

Creating a Culture of Ethical Accountability

Preventing CTE requires a cultural shift as much as a scientific one. Coaches, trainers, and physicians should be trained to recognize ethical red flags, such as pressuring players to return too quickly after injury or dismissing pain. The 2022 case of Miami Dolphins quarterback Tua Tagovailoa, who was cleared to return after suffering two concussions within five days before collapsing during the next game, reignited debate about lackluster concussion protocols and harmful institutional pressure. Leagues could implement mandatory ethics reviews following serious head injuries, ensuring that return-to-play decisions prioritize player welfare over short-term performance gains [48, 53, 54]. Youth leagues should partner with neurologists to develop age-appropriate contact rules and concussion management plans.

Through these combined efforts of transparent education, cultural adaptation, and ongoing scientific accountability, the future of contact sports can move toward a model that celebrates athleticism without sacrificing brain health. The challenge lies not in eliminating risk, but in redefining what it means to play ethically with full awareness of the brain’s fragility and worth.

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