Alcohol, Brain Function and Brain Damage
Alcohol produces its intoxicating effects in the human body by triggering a form of poisoning. Everyday examples of this poisoning’s impact on the central nervous system (brain and spinal cord) include temporary coordination problems, memory impairment and diminished speaking skills. Given time, the body can cope with modest amounts of alcohol through a natural detoxification process. However, people who drink excessively—either habitually or on isolated occasions—overwhelm their built-in detoxification abilities and set the stage for the potential onset of longer-lasting forms of brain alteration. In addition to the rate and frequency of alcohol consumption, the National Institute on Alcohol Abuse and Alcoholism lists factors in the development of alcohol-related brain damage that include one’s age, general state of physical well-being, history of exposure to alcohol in the womb, genetic predisposition toward alcoholism, age at the onset of alcohol intake and cumulative length of alcohol intake.
Over time, chronic exposure to excessive amounts of alcohol can trigger shrinkage in the brain’s overall size (or volume). Areas especially affected by this shrinkage include the part of the brain responsible for memory function and comprehension of spatial relationships, as well as the part of the brain responsible for such critical higher-level mental functions as planning, moral judgment, prediction of consequences, behavioral control and the ability to form reasonable expectations. Long-term exposure to high amounts of alcohol can also harm the parts of the brain that provide support for various primary brain functions.
Habitual heavy drinkers can also develop deficiencies of the B vitamin thiamine. In turn, a chronic thiamine deficiency can trigger a highly dangerous brain disorder called Wernicke-Korsakoff syndrome, which can lead to vision and muscle coordination problems, ongoing problems with both the ability to take in new information and the ability to use stored information, and a potentially fatal decline in the brain’s normal rate of chemical and electrical activity.
Presence in Teenagers and Young Adults
In the study review published in Alcohol and Alcoholism, the University of Edinburgh researchers analyzed the findings of 12 prior research efforts designed to track alcohol-related brain changes in people under age 40. Five of these previous studies focused on teenagers and young adults between the ages of 14 and 21, while the remaining seven focused on young adults in their 20s and 30s. The researchers conducted their review because they wanted to know just how early the signs of brain damage can appear in people affected by alcohol use disorder.
After completing their analysis, the researchers concluded that there is significant evidence to indicate the presence of alcohol-related brain shrinkage in both teenagers and young adults below the age of 40 affected by alcohol abuse or alcoholism. In teenagers, shrinkage in the two classically affected brain areas occurs in both female and male heavy drinkers; however, only heavy-drinking females in this age group experience shrinkage with consistent regularity. In young adults, shrinkage consistently occurs in both genders in the part of the brain responsible for the processing of higher-level mental functions. It also sometimes appears in the part of the brain responsible for memory processing and the ongoing comprehension of spatial relationships.
Significance and Considerations
In light of their findings, the authors of the study review published in Alcohol and Alcoholism conclude that alcohol use disorder (in the form of either alcohol abuse or alcoholism) can indeed produce noticeable, negative changes in the brain health of teenagers and young adults. To a certain extent, the damage present in teenagers resembles the damage present in young adults. However, adolescents appear to have a unique vulnerability to damage in the brain area responsible for memory and spatial processing. This vulnerability may stem from the ability of chronic, excessive alcohol consumption to interfere with the normal process of brain development.