Brain Scans Predict Alcohol Problems in Young Adults
Public health officials use alcohol consumption patterns to calculate the general risks that any given drinker will one day meet the criteria for diagnosing cases of alcohol abuse or alcoholism. As a rule, men who consume alcohol keep their chances for these problems in check when they imbibe no more than four drinks on any one day and no more than 14 drinks in any seven-day period. Women who consume alcohol typically keep their chances for developing serious problems in check when they imbibe no more than three drinks on any one day and no more than seven drinks in any seven-day period.
Depending on the specific amount of alcohol they consume, people who stay within these limits qualify as light or moderate drinkers. People who surpass these limits with any regularity qualify as heavy drinkers. Roughly 20 percent of all individuals who drink heavily once a month will develop a diagnosable case of alcohol use disorder. Roughly 33 percent of all individuals who drink heavily once a week will develop the disorder’s symptoms. Among individuals who drink heavily more than once a week, the alcohol use disorder rate rises to 50 percent.
The Brain and Alcohol
Alcohol is noted for its ability to substantially alter normal function inside the central nervous system, which includes both the brain and the spinal cord. Every time a person drinks in any significant amount, he or she undergoes short-term changes in the levels of several key chemicals, called neurotransmitters, which give the cells in the central nervous system their ability to communicate with each other. Changes in the levels of one specific neurotransmitter, called dopamine, are largely responsible for the pleasurable effects of alcohol consumption and the long-term risks for the development of alcohol use disorder.
Responses to Drinking Cues
In the study published in Addiction, researchers from Yale University, the University of Connecticut, Trinity College, Central Connecticut State University and Hartford Hospital used fMRI (functional magnetic resonance imaging) scans to examine the real-time changes in brain function that occur when young adult drinkers are exposed to photos of alcohol, rather than alcohol itself. These researchers wanted to know if different types of drinkers experience different brain responses when viewing such imagery. They also wanted to know if the brain responses they observed could help predict who would become a heavy drinker and thereby experience increased risks for serious alcohol-related problems.
All told, 43 individuals between the ages of 18 and 21 participated in the study. Each of these individuals underwent an initial fMRI exam while viewing photos of alcohol, and then regularly reported his or her involvement in alcohol use over the next 12 months. At the end of this yearlong period, each participant underwent a second fMRI exam while viewing photos of alcohol. Sixteen of the study participants qualified as heavy drinkers throughout the project; another 13 participants qualified as moderate drinkers throughout the project. A third group of participants qualified as moderate drinkers when the study began, but qualified as heavy drinkers by the time the study came to a close.
After matching up the fMRI results for each group of participants, the researchers came to a couple of conclusions. First, they concluded that, when looking at images of alcohol, the brain activity levels in the consistently heavy drinkers and the consistently moderate drinkers increased, but not to any major extent. However, when the participants who moved from moderate drinking to heavy drinking looked at images of alcohol, their brain activity levels increased considerably.
Significance and Considerations
Based on their findings, the authors of the study published in Addiction concluded that notable increases in the brain activity of moderate drinkers exposed to alcohol-related cues help predict the transition into problematic heavy alcohol consumption among young adults. Critically, this predictive power remains even when other well-known influences on problematic drinking (such as a high level of impulsive behavior and alcoholism in family bloodlines) are taken into consideration. The authors believe that brain scans may have unique value in determining which people have the highest odds of eventually developing problems.