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The following is a summary of “Chronic Traumatic Encephalopathy, Family History of Mental Illness, and Aggression in Brain Donors With Repetitive Head Impact Exposure,” published in the November 2024 issue of Neurology by Uretsky et al.   

Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy linked to repetitive head impacts, such as those from contact sports and military service. Previous studies have shown aggression in individuals with CTE but failed to connect tau burden with aggression. First-degree family history of mental illness (1^°FHMI) is a known risk factor for aggression.  

Researchers conducted a retrospective study to examine how CTE pathology influences the relationship between 1^°FHMI and aggression in individuals exposed to repetitive head impacts.  

They examined male brain donors with repetitive head impact exposure (n = 845) from 2014-2021 in the Understanding Neurologic Injury and Traumatic Encephalopathy Study (UNITE) at Boston University; CTE was diagnosed by neuropathologists using the National Institute of Neurological Disorders and Stroke (NINDS) criteria. Informants provided lifetime aggression data using the Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA) and reported on the donors’ 1^°FHMI. Linear regression assessed the relationship between 1^°FHMI and aggression scores, adjusting for factors such as race, age at death, education, contact sport participation, military service history, substance use treatment history, and history of psychologically traumatic events.  

The results showed 845 brain donors (mean age at death 60.3 years), 69.7% had CTE, and 45.3% had a 1^°FHMI). Additionally, 1^°FHMI was associated with higher aggression scores in individuals with CTE (β = 0.16, 95% CI 0.02-0.29) but not in those without CTE (β = 0.10, 95% CI −0.12 to 0.32). The largest effects were observed in individuals with CTE, aged 40–59 years (β = 0.64, 95% CI 0.32-0.96), particularly for emotional dysregulation/impulsiveness (β = 1.68, 95% CI 0.78–2.58) and antisocial behavior (β = 1.56, 95% CI 0.64–2.47).  

They concluded that CTE pathology may amplify the effect of a 1^°FHMI on aggression, particularly in midlife.  

Source: neurology.org/doi/10.1212/WNL.0000000000210056