Heavy alcohol use in both adolescence and in adulthood can cause discernable changes to the brain, according to a pair of recent research studies sponsored by the NIAAA (National Institute on Alcohol Abuse and Alcoholism, a division of the US National Institutes of Health).
In both studies these changes were found in regions responsible for things like impulse control and inhibition—the very brain functions needed to stop drinking and stay sober.
Long-Term Alcoholism Damages White Matter
The first study, led by researchers at Harvard Medical School, found that chronic alcoholism damaged white matter in areas of the brain that manage self-control and other functions required to maintain sobriety.
Researchers studied MRI images of the brains of 31 currently non-drinking subjects with a personal history of an average of 25 years of alcohol abuse and approximately 5 years of sobriety. These images were compared to those taken from 20 non-drinking subjects with no history of heavy drinking.
The participants with the history of heavy drinking had pronounced damage to white matter in their brains. White matter is responsible for signaling and communication between various brain regions. The regions affected in the long-term alcoholics included the amygdala, hippocampus, and nucleus accumbens—areas associated with impulse control and the type of function required to maintain abstinence.
The researchers found that damage was directly associated with how long and how much people drank. However, the damage was less severe in those who quit drinking before age 50, and researchers said that there may be potential for recovery of the white matter damaged in that younger age group.
The study was published in the December 2014 issue of Alcoholism: Clinical & Experimental Research
Binge Drinking in Adolescence Causes Long-Term Changes to the Brain
In another recent study, scientists found that binge-drinking during adolescence leads to changes in the prefrontal cortex that last into adulthood.
The research team at Medical University of South Carolina in Charleston exposed adolescent rats to alcohol vapor in a manner that mimicked the exposure found with episodes of binge drinking. When these rats reached adulthood, scientists put them through a series of tasks and compared scans of their brains to the brains of rats who were not exposed to alcohol in adolescence.
The “binge-drinking” rats had marked reductions in the volume of their hippocampus, thalamus, dorsal striatum, and neocortex, and increased volume in the hypothalamus.
How does that translate to behavior? When performing a task, these rats had less behavioral flexibility, characterized by inability to change strategy when needed and less inhibition. They also showed a poor ability to learn skills to help them stop self-administering alcohol.
However, these rats showed improvements in their abilities to resist alcohol when they were treated with a medication that improves the function of glutamate receptors in the brain, suggesting that this damage is not permanent.
This study was published in the October 2014 issue of Neuropsychopharmacology
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