Does Binge Drinking Interfere with Young Adult Brain Development?
Binge drinkers endanger themselves by consuming enough alcohol in a couple of hours to reach at least the minimum limits for legal intoxication. While most affected individuals are not alcoholics, the practice can lead to an eventual diagnosis of alcoholism or non-addicted alcohol abuse (known together as alcohol use disorder). Other potential harms firmly linked to binge drinking involvement include alcohol poisoning, exposure to accidental or intentional injuries, sexual assault victimization or participation, possibly life-threatening cardiovascular (heart and blood vessel) problems, damage to other key organ systems and exposure to HIV or other infections transmitted through unprotected sexual contact.
In the U.S., binge-drinking participation is heaviest among older teenagers and young adults below the age of 35. All of the four subgroups within this age range (18- to 20-year-olds, 21- to 25-year-olds, 26- to 29-year-olds and 30- to 34-year-olds) maintain an overall binging involvement rate of at least 30 percent. The single highest rate of involvement (45.1 percent) occurs among people between the ages of 21 and 25.
Young Adult Brain Development
By the time they reach the end of adolescence and enter their 20s, human beings have reached the final stages of their normal brain development. However, significant amounts of development are still underway in a part of the brain called the prefrontal cortex, which helps produce and regulate the higher-level mental skills that largely distinguish humans from other species. One crucial skill finalized during the transition from adolescence to adulthood is executive function; this term collectively describes the ability to do things such as make sound judgments, solve complex problems, make moral choices, accurately weigh the pros and cons of a given situation, make behavioral corrections when necessary, rein in impulsive urges and maintain control over emotional fluctuations. Typically, executive function and other prefrontal cortex-related skills do not fully develop until a person reaches roughly age 25.
In the study published in Alcoholism: Clinical & Experimental Research, researchers from Harvard Medical School and McLean Hospital used MRI (magnetic resonance imaging) scans to examine the prefrontal cortexes of 23 binge-drinking young adults with an average age of 22. These scans covered details that included the surface features of three structures contained in the prefrontal cortex, as well as the relative thickness of the prefrontal cortex. A second group of 31 young adult alcohol consumers who did not binge drink also took part in the study. These individuals underwent the same MRI scans as their binge-drinking counterparts.
After completing a comparison between the binge drinkers and the non-binge drinkers, the researchers concluded that the binge-drinking study participants had unusually thin tissues in two of the three prefrontal cortex structures under consideration. Among both groups of participants, the relative thickness of one of the prefrontal cortex structures was associated with three factors: the amount of alcohol consumed by an individual, the frequency of alcohol use and the amount of time since the last episode of alcohol consumption. The unusual tissue thinness in this structure that the researchers identified in binge drinkers was linked to both a high amount of alcohol consumed during binge-drinking episodes and relatively frequent involvement in binge drinking.
The study’s authors note that their project was not set up to determine if unusual prefrontal cortex thinness in the binge-drinking participants first appeared before or after the initiation of binge-drinking behavior. However, they emphasize the fact that the observed changes in normal brain development may be the direct result of frequent and toxic exposure to alcohol. Essentially, the effects of alcohol exposure may prematurely activate a “pruning” routine in the prefrontal cortex that usually tidies up the brain after the completion of the development process.