Symptoms

There are no specific symptoms that have been clearly linked to CTE. Some of the possible signs and symptoms of CTE can occur in many other conditions. In the few people with proved CTE, signs and symptoms have included cognitive, behavioral, mood and motor changes.

Cognitive impairment

• Difficulty thinking (cognitive impairment)
• Memory loss
• Problems with planning, organization and carrying out tasks (executive function)

Behavioral changes

• Impulsive behavior
• Aggression

Mood disorders

• Depression or apathy
• Emotional instability
• Substance misuse
• Suicidal thoughts or behavior

Motor symptoms

• Parkinsonism
• Motor neuron disease

CTE symptoms don't develop right after a head injury, but experts believe that they might develop over years or decades after repeated head trauma. Experts currently believe that CTE symptoms appear in two forms. In early life between the late 20s and early 30s, the first form of CTE may cause mental health and behavioral issues including depression, anxiety, impulsivity and aggression. The second form of CTE is thought to cause symptoms later in life, around age 60. These signs and symptoms include memory and thinking problems that are likely to progress to dementia.

The full list of signs to look for in people with CTE at autopsy is still unknown. It is unclear what kind of symptoms, if any, CTE may cause during life. Little is known right now about how CTE progresses.

When to see a doctor

CTE is thought to develop over many years after repeated brain injuries that may be mild or severe. However, see your doctor in case of the following:

• Suicidal thoughts. Research shows that people with CTE may be at increased risk of suicide. If you have thoughts of hurting yourself, call 911, your local emergency number or the National Suicide Prevention Lifeline at 800-273-TALK (800-273-8255).
• Head injury. See your doctor if you've had a head injury, even if you didn't need emergency care. If your child has received a head injury that concerns you, call your child's doctor immediately. Depending on the signs and symptoms, your doctor may recommend seeking immediate medical care.
• Memory problems. See your doctor if you have concerns about your memory or other thinking (cognitive) or behavior problems.
• Personality or mood changes. See your doctor if depression, anxiety, aggression or impulsivity occur.