Brain networks for sustained attention in teens predict substance use in young adulthood

A recent study published in the journal eLife has found that teenagers with lower sustained attention ability may be at higher risk of cigarette and cannabis use in early adulthood. Researchers observed that adolescents with reduced capacity to maintain focus on tasks had an increased likelihood of smoking and using cannabis by their early 20s. This insight marks the first evidence that poor sustained attention can predict future substance use.

Previous studies had shown an association between smoking or cannabis use and lower sustained attention, a mental skill that allows people to focus over extended periods. However, these studies only confirmed that a correlational association existed, rather than establish if poor attention led to substance use or resulted from it. Understanding whether a lack of attention might be a precursor to drug use could be vital for developing early preventive interventions.

“This research was conducted to investigate whether lower sustained attention preceded, or followed, substance use. Previous studies were often cross-sectional, with relatively few participants, leaving the relationship between sustained attention and substance use unclear,” explained study author Robert Whelan, a professor of psychology at the Global Brain Health Institute and School of Psychology at Trinity College Dublin and author of Methods for Analyzing Large Neuroimaging Datasets.

To explore this question, the research team analyzed data from the IMAGEN project, a large-scale study that follows over 1,000 individuals across Europe as they grow from adolescence into adulthood. The IMAGEN project gathers behavioral and neuroimaging data, including brain scans that measure brain activity related to sustained attention.

The team examined the participants’ sustained attention at ages 14, 19, and 23, along with self-reported data on their cigarette and cannabis use at these ages. By tracking sustained attention and substance use over several years, the researchers could assess if lower attention ability at age 14 predicted increased substance use in young adulthood.

The study used specific techniques to measure and predict participants’ attention. At each age, participants completed a “stop signal task,” a well-known assessment used to evaluate sustained attention. Participants were shown arrows on a screen and had to press a button in the direction of the arrow but stop their response if the arrow changed suddenly. The researchers measured participants’ reaction times and accuracy during these tasks to determine each participant’s level of sustained attention.

For the brain activity portion of the study, researchers used MRI technology to measure brain connectivity, focusing on areas known to be involved in sustained attention. These included regions of the prefrontal and parietal cortex, which play key roles in focus, impulse control, and processing information over time. Researchers used this brain imaging data to create predictive models, looking for patterns in brain activity that could indicate sustained attention levels.

When the team analyzed the data, they found that adolescents with lower sustained attention were indeed more likely to show an increase in cigarette and cannabis use as they reached young adulthood. For example, they observed that lower attention at age 14 was linked to higher cannabis and cigarette use by age 23.

Interestingly, this trend was consistent regardless of the participants’ initial levels of drug use. Moreover, brain connectivity patterns associated with low sustained attention also pointed to higher future substance use. Brain networks related to attention appeared to play a consistent role over time, suggesting that these networks might be reliable indicators of who is at higher risk of substance use.

The researchers proposed that these findings could have practical implications. By identifying teenagers with lower sustained attention skills, schools and communities could implement targeted programs to help them strengthen their focus. Programs designed to boost attention, such as cognitive training exercises, might help reduce the risk of future substance use. This early intervention strategy could provide a new approach to substance use prevention by helping teens develop better attention skills during a critical developmental period.

But as with all research, there are some caveats. Although the study provides significant insight into the link between attention and substance use, the study’s results are based on correlations, meaning they cannot fully prove a cause-and-effect relationship. Additionally, while the IMAGEN project includes a large sample size, the participants are all based in Europe, which may limit the generalizability of the findings to populations outside of this region.

“Future research could investigate the roles of specific neurotransmitters in the relationship between substance use and sustained attention,” Whelan said. “Furthermore, given that it is practical to improve sustained attention through cognitive training (e.g., tonic and phasic alertness/attention training, (Fortenbaugh et al., 2017)), future studies should explore whether enhancing sustained attention via cognitive training could reduce substance use. This approach would be significant in providing guidance for the prevention and treatment of adolescent substance use, thereby improving individual lives, and lessening societal burdens related to addiction.”

The study, “A robust brain network for sustained attention from adolescence to adulthood that predicts later substance use,” was authored by Yihe Weng, Johann Kruschwitz, Laura M. Rueda-Delgado, Kathy L. Ruddy, Rory Boyle, Luisa Franzen, Emin Serin, Tochukwu Nweze, Jamie Hanson, Alannah Smyth, Tom Farnan, Tobias Banaschewski, Arun L.W. Bokde, Sylvane Desrivières, Herta Flor, Antoine Grigis, Hugh Garavan, Penny A. Gowland, Andreas Heinz, Rüdiger Brühl, Jean-Luc Martinot, Marie-Laure Paillère Martinot, Eric Artiges, Jane McGrath, Frauke Nees, Dimitri Papadopoulos Orfanos, Tomas Paus, Luise Poustka, Nathalie Holz, Juliane Fröhner, Michael N. Smolka, Nilakshi Vaidya, Gunter Schumann, Henrik Walter, and Robert Whelan.