A recent study was published in the Journal of Alzheimer’s Disease studying the relationship between substance abuse and CTE. In short they found “substance use treatment had no associations with neuropathological endpoints“.

In the study, titled Clinical and Neuropathological Correlates of Substance Use in American Football Players, the researchers studied the brains of 429 deceased football players. 73% of them had confirmed CTE on autopsy. 23% had a substance use treatment history. Family members were also interviewed to learn about substance use histories. The researchers found that while substance use disorders were related with some of the symptoms the athletes suffered from that it had no association with neuropathological endpoints.

The full abstract reads as follows:

Background:

Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy more frequently found in deceased former football players. CTE has heterogeneous clinical presentations with multifactorial causes. Previous literature has shown substance use (alcohol/drug) can contribute to Alzheimer’s disease and related tauopathies pathologically and clinically.

Objective:

To examine the association between substance use and clinical and neuropathological endpoints of CTE.

Methods:

Our sample included 429 deceased male football players. CTE was neuropathologically diagnosed. Informant interviews assessed features of substance use and history of treatment for substance use to define indicators: history of substance use treatment (yes vs no, primary variable), alcohol severity, and drug severity.

Outcomes included scales that were completed by informants to assess cognition (Cognitive Difficulties Scale, BRIEF-A Metacognition Index), mood (Geriatric Depression Scale-15), behavioral regulation (BRIEF-A Behavioral Regulation Index, Barratt Impulsiveness Scale-11), functional ability (Functional Activities Questionnaire), as well as CTE status and cumulative p-tau burden. Regression models tested associations between substance use indicators and outcomes.

Results:

Of the 429 football players (mean age?=?62.07), 313 (73%) had autopsy confirmed CTE and 100 (23%) had substance use treatment history. Substance use treatment and alcohol/drug severity were associated with measures of behavioral regulation (FDR-p-values<0.05, ?R2?=?0.04–0.18) and depression (FDR-p-values<0.05, ?R2?=?0.02–0.05). Substance use indicators had minimal associations with cognitive scales, whereas p-tau burden was associated with all cognitive scales (p-values <0.05). Substance use treatment had no associations with neuropathological endpoints (FDR-p-values>0.05).

Conclusions:

Among deceased football players, substance use was common and associated with clinical symptoms.