Interaction of Medical Conditions and Football Exposures Associated with Premortem Chronic Traumatic Encephalopathy Diagnosis in Former Professional American Football Players.

BACKGROUND AND OBJECTIVE: Despite being a postmortem diagnosis, former professional American-style football players report receiving chronic traumatic encephalopathy (CTE) diagnoses from medical care providers. However, many players also report other health conditions that manifest with cognitive and psychological symptoms. The purpose of this study was to identify how medical conditions, psychological disorders, and football exposure combinations are associated with former athletes reporting a premortem CTE diagnosis.

METHODS: This study was a cross-sectional cohort survey from 2015 to 2019 of 4033 former professional American-style football players. Demographics (age, race, domestic status, primary care recipient), football-related factors (position, years of professional play, burden of symptoms following head impacts, performance-enhancing drug use), and comorbidities (sleep apnea, psychological disorder status [depression and anxiety; either depression or anxiety; neither depression nor anxiety], diabetes mellitus, attention-deficit/hyperactivity disorder, hypertension, heart conditions, high cholesterol, stroke, cancer, low testosterone, chronic pain, current and maximum body mass index) were recorded. A Chi-square automatic interaction detection (CHAID) decision tree model identified interactive effects between demographics, health conditions, and football exposures on the CTE diagnosis.

RESULTS: Depression showed the strongest univariate association with premortem CTE diagnoses (odds ratio [OR] = 9.5, 95% confidence interval [CI] 6.0-15.3). CHAID differentiated participants with premortem CTE diagnoses with 98.2% accuracy and area under the curve = 0.81. Participants reporting both depression and anxiety were more likely to have a CTE diagnosis compared with participants who reported no psychological disorders (OR = 12.2; 95% CI 7.3-21.1) or one psychological disorder (OR = 4.5; 95% CI 1.9-13.0). Sleep apnea was also associated with a CTE diagnosis amongst those with both depression and anxiety (OR = 2.7; 95% CI 1.4-5.2).

CONCLUSIONS: Clinical phenotypes including psychological disorders and sleep apnea were strongly associated with an increased likelihood of having received a pre-mortem CTE diagnosis in former professional football players. Depression, anxiety, and sleep apnea produce cognitive symptoms, are treatable conditions, and should be distinguished from neurodegenerative disease.