Signs of CTE in Men | What Research Shows and What It Cannot Confirm

Most published cases of Chronic Traumatic Encephalopathy have been in men. That is a fact about who has been studied, not a fact about who can develop the disease. The reason is exposure: the activities most strongly linked to CTE (contact sports like football, boxing, and hockey, plus military combat and blast exposure) have historically been male-dominated. As participation patterns change, the research is changing with them.

This page covers what the medical literature has documented in male cases, the clinical patterns families and partners most often notice, and why the same symptoms can have many other explanations. Everything here is based on peer-reviewed research, primarily from the Boston University CTE Center, the NINDS consensus criteria, and large clinicopathological case series.

First, the diagnostic reality

CTE cannot be diagnosed in any living person, male or female. The disease is defined by a specific pattern of abnormal tau protein in brain tissue that can only be seen under a microscope at autopsy. What can be evaluated in a living person is a related clinical syndrome called Traumatic Encephalopathy Syndrome (TES), which has formal diagnostic criteria published in 2021.

If you want to understand the diagnostic framework before reading the rest of this page, start with our companion article: How to Know If You Have CTE.

Why most documented cases have been in men

Three overlapping reasons explain the male skew in the CTE literature.

Contact sport participation. American football, boxing, ice hockey, rugby, and wrestling have historically been male-dominated at the professional and collegiate levels where repetitive head impact exposure is highest. The largest brain donation studies (the VA-BU-CLF Brain Bank, the Australian Sports Brain Bank) have therefore enrolled predominantly male donors.

Military service. Combat roles with the highest exposure to blast waves and breaching activity have historically been filled by men. Veterans of these roles are a significant population in CTE research.

Brain donation patterns. Families of male athletes and veterans who experienced cognitive or behavioral changes have been more likely to donate brain tissue for CTE research, partly because the public association between CTE and football has driven those donations.

Female cases do exist in the published literature. A landmark 2023 case report documented CTE in a female Australian rules football player. Multiple cases have been published linking CTE to intimate partner violence in women, with the first such case reported in 1990. As of 2025, Mount Sinai's Brain Injury Research Center is conducting the largest brain autopsy study of female intimate partner violence decedents, and the pathology being observed differs in some respects from male contact-sport cases. This is an active area of research.

For men, the documented case base is large enough that researchers have been able to describe consistent clinical patterns. Those are what follow.

Clinical signs documented in male cases

The patterns below come from published case series and the 2021 NINDS consensus criteria. They do not describe every case, and no single sign confirms CTE.

Mood and behavior changes

In documented case series, mood and behavioral symptoms often appear earlier than cognitive symptoms, especially in men who present at younger ages. Patterns reported include:

• Increased irritability or shorter fuse than the person had before
• Explosive episodes or rage that feels disproportionate to the trigger
• Impulsivity, including financial, sexual, or interpersonal decisions out of character
• Depression that feels different from prior episodes of depression
• Apathy: a loss of motivation or interest in things the person used to care about
• Increased anxiety, paranoia, or suspiciousness
• Suicidal ideation, which is a recognized feature in some case reports but not in others

Cognitive changes

The 2021 NINDS criteria define the cognitive features of TES as impairment in episodic memory (the ability to remember recent events) and/or executive functioning (planning, organization, judgment, multi-tasking). In men, these typically include:

• Trouble remembering recent conversations or events
• Repeating the same questions or stories
• Difficulty managing tasks that used to be routine (paying bills, following instructions, organizing a day)
• Word-finding problems
• Slowed processing speed
• Loss of insight: not recognizing the changes that family members are noticing

Motor and physical changes

Motor symptoms are less consistent than mood and cognitive symptoms but appear in a subset of cases, often later in the disease course:

• Slowed movement
• Tremor
• Balance problems or unsteady gait
• Speech changes, including slurring or word-retrieval difficulty
• Headaches, sometimes with changing patterns over time

Sleep and autonomic changes

Sleep disturbances are commonly reported in male CTE cases. These include difficulty falling asleep, fragmented sleep, vivid dreams or nightmares, and acting out dreams (a feature called REM sleep behavior disorder, which is also seen in Parkinson's disease and related conditions).

Why these signs are so easy to misattribute

Every symptom listed above has other possible causes. In men with significant repetitive head impact exposure, the overlap is particularly important to understand, because misattribution cuts both ways. Some men with treatable conditions are told "it's probably CTE" and never get the workup they need. Some men with CTE pathology have their symptoms dismissed as "just stress" or "just getting older."

Conditions that commonly produce overlapping symptoms include:

• Post-traumatic stress disorder. Particularly common in veterans, and the symptom overlap with TES is substantial. PTSD is treatable. (See our article on CTE vs PTSD and Depression.)
• Major depressive disorder. Can produce cognitive symptoms (pseudodementia) that resemble early dementia.
• Sleep apnea. Underdiagnosed in middle-aged men. Can cause cognitive impairment, mood changes, and headaches.
• Alcohol use disorder. Chronic heavy alcohol use produces overlapping cognitive and behavioral changes.
• Thyroid disease, vitamin B12 deficiency, and other metabolic conditions. All treatable, all can mimic cognitive decline.
• Medication side effects. Particularly anticholinergic medications, sedatives, and certain pain medications.
• Other neurodegenerative diseases. Alzheimer's disease, frontotemporal dementia, and Lewy body dementia can all overlap clinically with TES.

A neurologist or neuropsychologist evaluates all of these before considering TES as the most likely explanation.

Who is at higher risk among men

Based on the 2021 NINDS consensus criteria and the underlying case series, the men at highest documented risk of developing CTE pathology are those with substantial exposure to repetitive head impacts. The criteria offer specific exposure thresholds, including:

• At least five years of organized American football participation, with two or more years at the high school level or beyond
• Significant participation in other contact or collision sports (boxing, ice hockey, rugby, wrestling, mixed martial arts, soccer with heading exposure)
• Military service involving blast exposure, breaching activity, or other repetitive head impact
• History of multiple concussions, particularly with incomplete recovery between events
• History of physical assault with head impact

The relationship between exposure and CTE risk appears to be dose-dependent in the available data: more years of exposure correlates with higher risk and more severe pathology.

That said, exposure does not equal diagnosis. Many men with significant exposure do not develop CTE. Genetic factors, age at first exposure, and other variables that researchers are still studying appear to play a role.

What to do if you are worried about a man in your life

1. Document the changes. Specific examples with dates are far more useful to a clinician than general impressions. Keep a behavior log.
2. Document the exposure history. Sports, years of participation, military service details, any documented concussions, any history of physical assault.
3. Request a neurology referral. Behavioral neurology or neuropsychology is the right specialty.
4. Ask for a complete workup. Rule out the treatable conditions first. Bloodwork, sleep evaluation, medication review, mood assessment.
5. If exposure history fits, consider a research-affiliated center. The Boston University CTE Center, the Concussion Legacy Foundation HelpLine, and the VA's TBI research programs can connect families to evaluation and research opportunities.
6. Take care of yourself. Caregiver burnout is real, and partners of men with neurobehavioral changes carry an enormous load. Our CTE Caregiver Support page is built for exactly this situation.

A note for veterans and military families

CTE in veterans often presents differently than CTE in former athletes, partly because the exposure pattern is different (blast waves, breaching, repeated subconcussive impacts during training) and partly because PTSD and TBI frequently coexist with suspected CTE. We have a dedicated page on CTE in Veterans that goes into this in more depth.

Continue learning

• How to Know If You Have CTE
• Understanding CTE: the full hub
• CTE Symptoms and Warning Signs
• Early Warning Signs Families Often Notice First
• CTE vs PTSD and Depression
• CTE in Veterans
• CTE Caregiver Support

Free resource for caregivers

If you are caring for a man with suspected CTE, our free CTE Caregiver Guide walks you through what to track, what to bring to appointments, and how to navigate the diagnostic process.

Subscribe to From the Nest

Our free weekly newsletter delivers one short letter every Wednesday with real caregiving and real science. Subscribe here.

Sources and further reading

1. Katz DI, Bernick C, Dodick DW, et al. National Institute of Neurological Disorders and Stroke Consensus Diagnostic Criteria for Traumatic Encephalopathy Syndrome. Neurology. 2021;96(18):848-863. doi:10.1212/WNL.0000000000011850
2. McKee AC, Stern RA, Nowinski CJ, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(1):43-64. doi:10.1093/brain/aws307
3. Mez J, Daneshvar DH, Abdolmohammadi B, et al. Duration of American football play and chronic traumatic encephalopathy. Annals of Neurology. 2020;87(1):116-131.
4. Stern RA, Daneshvar DH, Baugh CM, et al. Clinical presentation of chronic traumatic encephalopathy. Neurology. 2013;81(13):1122-1129.
5. Suter CM, Affleck AJ, Pearce AJ, et al. Chronic traumatic encephalopathy in a female ex-professional Australian rules footballer. Acta Neuropathologica. 2023. doi:10.1007/s00401-023-02610-z
6. McKee AC, Cairns NJ, Dickson DW, et al. The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy. Acta Neuropathologica. 2016;131(1):75-86. doi:10.1007/s00401-015-1515-z

Medical disclaimer: This page is educational and is not a substitute for professional medical evaluation. If you are concerned about cognitive or behavioral changes in yourself or a loved one, please consult a qualified healthcare provider.

Robbins Nest Alliance is a 501(c)(3) educational nonprofit. EIN: 39-2763662. We publish free, medically-cited brain injury education for caregivers and families.