Key Takeaways
|
Ever notice that some days you can power through a spreadsheet but still can’t stop your mind from wandering during a long meeting? That split experience, sharp problem solving on one hand and wandering focus on the other, might not just be a mood or a bad night’s sleep. According to a recent study these two experiences may be shaped by genetically distinct systems in the brain.
The study, published in Molecular Psychiatry, is the first large-scale look at the genetics of sustained attention (your ability to stay locked in on a task over time) and executive function (the mental toolkit you use to plan, remember and switch between tasks). The findings suggest these two forms of cognition, long assumed to overlap heavily, are influenced by largely separate genetic factors, and that each has its own distinct relationship with psychiatric conditions like ADHD and alcohol use disorder
Two Cognitive Systems, Two Genetic Signatures
Previously, more than 23,000 participants in the AFFECT study, a research collaboration between 23andMe and the brain health company Lundbeck, completed a battery of computerized cognitive tasks over nine months. One task measured sustained attention by tracking how consistently people responded to a stream of frequent images while withholding responses to occasional oddball images. Others measured executive function skills such as processing speed, working memory and how quickly people can select the correct response among competing options.
This new study found that six cognitive measures could be grouped into two genetic factors. The first, which the researchers labeled Executive Function, was strongly tied to processing speed, working memory and response selection. The second, Sustained Attention, was most closely tied to vigilance (moment-to-moment consistency) and how often attention lapsed altogether.
For both factors, common genetic variants explain a real, though modest, share of the differences between people. That’s in line with what’s typically seen for complex cognitive traits, where hundreds of genetic variants each contribute a small effect rather than any single gene calling the shots.
Notably, the Executive Function and Sustained Attention factors were not significantly correlated, meaning that at the genetic level your capacity to stay focused over time and your capacity to juggle and manipulate information appear to be independent.
What This Means for ADHD, Depression and Other Conditions
Because psychiatric conditions so often involve attention and cognitive control problems, the researchers also tested how each genetic factor related to 13 different psychiatric conditions. Researchers found that the genetic variants linked to stronger executive function are also linked to a lower predisposition for many conditions including ADHD, anxiety disorder, bipolar disorder and schizophrenia. The genetic variants linked to stronger sustained attention were linked to a lower predisposition for just ADHD and alcohol use disorder.
After researchers accounted for the genetic overlap between the two factors, Sustained Attention and Executive Function each still showed their own separate association to ADHD. This suggests that attention problems in ADHD may involve more than one genetic pathway. In other words, ADHD isn’t just tied to one set of attention-related genes, it’s tied to at least two separate ones.
The researchers also looked for genetic links between these cognitive factors and brain structure. In the end, no relationships reached statistical significance, a reminder that connecting genetic differences to changes in brain anatomy typically requires far larger sample sizes than are currently available.
What Comes Next
The AFFECT cohort, while one of the largest of its kind for these particular cognitive tasks, is not yet large enough to pinpoint the individual genetic variants involved. Additionally, the analysis was limited to participants with European genetic ancestry, meaning genetic insights like these may apply best to those with European ancestry, leaving other communities underrepresented. Expanding these studies to more ancestrally and demographically diverse cohorts will be an important next step toward research that benefits everyone.
None of this means your genes lock in your ability to focus. Genetics is only one factor among many, such as sleep, stress, environment and practiced habits, that shape how attention and executive function show up in daily life. What this study does offer is a clearer map of where the underlying biology diverges, which may eventually help researchers understand why some treatments for attention and mood difficulties work better for some people than others.
Findings like these exist because thousands of research participants have generously shared their genetic data and time with our researchers. Their contributions are helping build a better understanding of health for all of us. Your DNA could help us make new discoveries. Learn more about our research.
