Brain network activity may offer clues to future drinking behaviors of adolescents

Measuring the interaction of brain networks could potentially help identify teens at risk for dangerous drinking, according to a novel study that explored how brain signals relate to future drinking behavior. Alcohol use commonly starts and escalates during adolescence, which is a key period for brain development. Drinking can alter brain development in ways that increase the risk of alcohol use disorder (AUD).

Understanding which factors predispose some teens to heavier or more frequent alcohol use could help prevent AUD and its associated burdens. While previous research has examined the brain’s structure for clues to teens’ future drinking risk, a study of functional brain network dynamics—how brain regions communicate with each other from moment-to-moment—may hold more promise.

For the study in Alcohol: Clinical & Experimental Research, investigators in North Carolina explored whether brain network dynamics could help predict drinking in adolescents.

The researchers worked with MRI data from 295 17-year-old participants who either did not use alcohol or who drank lightly: 52% were female, 73% were white, and 11% were Hispanic. This data came from the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA). Participants underwent functional MRI scans—to measure their brain function at rest.

Using this data, investigators examined how participants’ brains moved through a sequence of brain “states,” the first time this approach has been applied to teen drinking. One year after their brain scans, the participants completed a questionnaire detailing their alcohol use since the scan.

The researchers used drinking frequency and drinking intensity (the largest amount of alcohol consumed in one time period) as behavioral markers. Statistical analysis explored the relationship between time spent in brain states at age 17 and drinking behavior over the next year. Analyses also explored whether findings varied by sex.

During the brain scans, time spent in various brain states was similar among those who used any alcohol in the year following their scans and those who did not. Among people who drank, however, researchers identified associations between the time spent in certain brain states and future drinking frequency.

More time in a state with high activation in the brain’s Default Mode Network—a network associated with mental health and behavior—was linked to fewer drinking days over the next year, suggesting that more time in that state may protect against future alcohol use. For other brain states, the relationships between time spent in the state and future drinking frequency differed by sex; this is the first study to find this difference.

Brain dynamics among teens who didn’t drink or drank lightly were linked to future drinking frequency but not to drinking intensity. It’s possible that brain dynamics, which may potentially flag vulnerability to AUD, are more informative about the regularity of behaviors than the sporadic intensity of behaviors.

Some variations in outcomes by sex should be interpreted cautiously until corroborated. In addition, although resting-state brain activity has been shown to indicate future behaviors, how teen brain dynamics might differ in a real-life environment is not known.