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What is the prevalence of chronic traumatic encephalopathy (CTE) in law enforcement?

Understanding the long-term effects of CTE can assist with strategies to address officer mental health

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Providing the necessary assistance to LEOs is imperative to reduce the troubling trend of deaths by suicide.


By Matt Walsh

Chronic traumatic encephalopathy (CTE) is a degenerative brain disease found in people who have suffered concussive and/or sub-concussive hits to the head that trigger the protein Tau to abnormally form in the brain.

Excessive amounts of Tau deteriorate brain tissue, often leaving the patient with side effects like memory loss, confusion, impaired judgment, impulse control problems, aggression, depression, suicidality, parkinsonism and dementia.

CTE is widely documented as responsible for negative diagnoses such as parkinsonism and dementia among professional athletes and U.S. military personnel. Most notable are the reported suicides by athletes and service members diagnosed with CTE after their death.

This article highlights the similarities between law enforcement officers, athletes and service members and explores the potential prevalence of CTE in law enforcement. Understanding the long-term effects of CTE in law enforcement can assist with strategies to address officer mental health.

The link between brain injuries and CTE

Currently, the only avenue to diagnose CTE is through a post-mortem exam when the brain can be dissected to determine the presence of the tau protein.

CTE has been diagnosed in athletes and service members who experienced repetitive traumatic brain injuries (TBIs) and mild traumatic brain injuries (mTBIs) that can be caused by sub-concussive and/or concussive hits to the head. These injuries result in symptoms such as loss of consciousness, headaches, nausea, vision impairments, dizziness and sleep problems. Long-term consequences of suffering from mTBIs and TBIs can result in a diagnosis of CTE.

Unsure of how to support wounded officers and their families? Dr. Patricia Kay Reyna shares the deeply personal story of her family’s journey through trauma and healing after her husband, a North Carolina State Highway Patrol Master Trooper, suffered a traumatic brain injury on duty. Listen to the full Policing Matters podcast here.

It has been determined that veterans and service members with a history of playing contact sports had an increased risk of developing CTE. It was further concluded that CTE was found in veterans and service members who were exposed to blasts and low-level blasts with no history of sports participation.

LEOs are a diverse group of people with a history of sports participation and/or military service who have suffered blast and low-level blast injuries. LEOs with no prior military service are exposed to low-level blasts in the form of repeated exposure to various types of gunshots as part of training. SWAT operators are routinely exposed to more low-level blasts from distraction devices, commonly referred to as flashbangs. Police snipers are routinely exposed to large caliber gunfire such as .308 and .50 caliber rifle rounds. Entry members are exposed to flashbangs and explosive entry techniques.

It is estimated that one-third of LEOs exhibit signs and symptoms of post-traumatic stress disorder (PTSD), a trauma or stress-related disorder that may develop following a witnessed traumatic event such as exposure to actual or threatened death, serious injury, or sexual violence.

Signs and symptoms of CTE and PTSD resemble each other such as depression, confusion, memory loss, suicidality, negative emotional state, self-destructive behavior, hypervigilance, inability to concentrate, inability to sleep, anger and depression.

Could a PTSD diagnosis be CTE?

To better understand the potential link between CTE and PTSD affecting LEOs, a survey was constructed utilizing past research conducted on athletes and service members to include sports participation and exposure to blasts and low-level blasts.

The occurrence of CTE in both athletes and service members causes concern for LEOs due to their potential participation in contact sports and exposure to blasts and low-level blasts throughout a 30-year career. A confidential and anonymous survey was sent to 4,458 Florida LEOs, which asked them about their history of sports participation, and years of police experience, SWAT and military experience.

Of the 589 LEOs who completed the survey, the results illustrate that LEOs share similarities with athletes and service members. LEOs participated in contact sports and have been exposed to blasts and low-level blasts. It is alarming that more than 84% of the LEOs reported sub-concussive hits to the head, with 20% suffering from a range of 6 to 20 and 19% suffering from 21 or more.

More alarming is that 79% reported suffering concussive hits to the head with more than 430 LEOs identifying between 1 to 5 concussive hits. It should be concerning that LEOs who reported suffering from sub-concussive hits and concussive hits were largely self-reporting with a small number being clinically diagnosed with concussions. Only 32% reported being diagnosed with at least one concussion.

The link between CTE and PTSD signs and symptoms previously addressed points are in direct correlation with what has become the leading cause of death for LEOs, death by suicide. In 2019, there were 228 verified LEO deaths by suicide, which outnumbers the 2019 line of duty deaths of 154. The results of this survey highlight the possibility that LEOs experience physical changes to their brains, which may aid in understanding and explaining suicide, failed relationships, substance abuse, excessive force complaints and a variety of neurocognitive diseases.

CTE needs to be formally studied in law enforcement to determine the rate in which CTE impacts the law enforcement community. Three recommendations are proposed to address the potential long-term effects of mTBIs, TBIs, CTE and PTSD:

1. Medical interventions

If CTE can be established as occurring in law enforcement, medical interventions can be implemented to assist those LEOs determined to be at high risk of developing CTE.

In Florida, Senate Bill 376 was introduced, making PTSD in first responders a primary medically qualifying event for retirement. The bill was passed and enacted into law in 2018. Florida State Statute 112.1815 establishes certain situations where a PTSD diagnosis enables the LEO to medically retire under workman’s compensation. This was considered a win for all first responders to remove the stigma of suffering from PTSD.

This law was meant to provide for the first responder and their family should the affected LEO be diagnosed with PTSD. A requirement of this law, and possible weakness, was that the first responder must be diagnosed with PTSD within 365 days of the qualifying event as outlined in the statute.

As a result of this research and the correlation between CTE and PTSD, it is recommended that any diagnosis of PTSD during the LEO career be eligible for medical retirement under worker’s compensation. The effects of sub-concussive and concussive hits to the head may take years to manifest into signs and symptoms of PTSD and, ultimately, CTE. Because CTE can only be diagnosed post-mortem, diagnosed PTSD with a history of subconcussive and concussive hits to the head should be considered as a precursor to CTE. This ultimately should provide lifelong medical coverage to the affected LEO.

2. Critical incident management/peer support teams

Law enforcement agencies should implement critical incident management/peer support teams to assist officers in times of crisis. This can result in increased self-awareness and a more productive workforce.

Agencies should consider employing in-house licensed mental health professionals to facilitate the peer support groups, as well as provide mandatory counseling for the LEOs. Mandatory counseling serves as a way to remove the stigma associated with receiving mental health counseling. The peer support team and employing mental health professionals also serve as an early intervention for LEOs who may be suffering from signs and symptoms of PTSD and CTE. This, in turn, will likely reduce the number of suicides, failed marriages and self-destructive behavior like substance misuse.

3. Training and education

Lastly, training and education to include PTSD, CTE and mental health should be implemented as a mandatory block of instruction in the basic academy curriculum. Continued training and education in this area should also be mandatory throughout an officer’s career.

LEOs should be educated in the PTSD laws, or similar laws in other states, so they can recognize signs and symptoms in them and their colleagues. LEOs should advocate for an expansion of the PTSD law to include a PTSD diagnosis during any part of their career. Each state should enact a PTSD law that provides for benefits for the LEO.


Regardless of the diagnosis of PTSD or CTE, the trauma-informed, evidence-based treatment should be similar. Eye movement desensitization and reprocessing (EMDR) and accelerated resolution therapy (ART) are two evidenced-based techniques utilized to treat veterans and LEOs. Both techniques aim to reduce the distress associated with a traumatic event(s) and how the traumatic memory is stored in the brain.

Providing the necessary assistance to LEOs is imperative to reduce the troubling trend of deaths by suicide. Mandatory mental health wellness visits will eliminate the stigma of seeking help. Establishing critical incident stress management/peer support teams, early education at the academy level, and continued mental health education are some interventions that may help in reducing the major issue affecting the physical safety and mental health of police officers.

To learn more about CTE and the latest research, visit the CTE Center. To learn more about concussions and the lasting effects, visit the Concussion Foundation.


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About the author

Matt Walsh is a 23-year law enforcement professional and the Assistant Special Agent-in-Charge for the Florida Department of Law Enforcement Jacksonville Regional Operations Center. His career includes assignments in patrol, homicide, SWAT, organized crime and public integrity before promoting into leadership positions. Matt currently supervises 40 special agents and supervisors and trains law enforcement members in best practices for conducting death and homicide investigations.

Matt is beginning his last semester pursuing his Master of Social Work degree from Florida State University. Matt and his wife, Michelle, a Licensed Clinical Social Worker, travel Florida to train law enforcement in stress management, suicidality and resiliency. Matt is the FDLE Statewide Coordinator for the Critical Incident Stress Management and Peer Support Team. Matt has led interventions following the Pulse nightclub attack, the Broward Airport shooting, the Parkland school shooting, the Sebring mass shooting and other critical incidents.