According to the results of a recent research study, lower intelligence scores in young adulthood are significantly associated with a higher risk of developing alcohol use disorder later in life. The study, published in the peer-reviewed journal JAMA Psychiatry, was a research collaboration between several institutions, including Linköping University, the University of Pennsylvania, Karolinska Institute, the University of Toronto, the University of Hamburg, and Yale University.
The study cohort included 573,855 male participants from the Swedish Military Conscription Register who were born between 1950 and 1962, and used participants’ data from national health registers that include clinical diagnoses of alcohol use disorder (AUD). The results of the study demonstrated intelligence measured as an IQ score at the age of 18 years showed a clear inverse association with later risk of developing AUD. Specifically, men with lower IQ scores were significantly more likely to develop AUD over time, even after accounting for parental substance use, psychiatric conditions, socioeconomic background, and birth year.
“The findings suggest that causal pathways from cognitive performance to alcohol use outcomes are not universal and that structural conditions can magnify or mitigate the effects of genetic predispositions,” wrote the authors. “Taken together, findings of this study demonstrate that the association between cognitive traits and AUD was shaped by both genetic liability and the broader sociocultural environment in which that genetic liability is expressed. Across multiple methods and samples, cognitive performance and IQ were associated with AUD risk, but the nature of the association varied across contexts.”
Moreover, the results also indicate that in societies with more equitable access to education and healthcare, such as Sweden and Finland, education can reduce the risk of AUD linked to lower cognitive ability or IQ. However, in more socially “stratified” settings, education can heighten this vulnerability by reinforcing inequalities in health and opportunity. “Efforts to mitigate AUD risk should account not only for individual differences in cognitive traits but also the structural conditions that shape how these differences manifest in health outcomes,” concluded the study authors.
