After a hard day or week, some of us look forward to unwinding with a drink or two. And, sometimes, a few drinks turn into a few more. When you’re over the legal drinking age, can still function, and you’re mentally healthy, it’s no big deal, right?
Maybe not. First, those few drinks may actually equal a binge. Second, research is showing the effects of those drinks on our brains—not just the night of, or the morning after, but well into the week, when we’re working on our papers or prepping for finals.
What is a binge, really?
You’ve heard of binge drinking, and you know there are consequences (e.g., bad decisions, blackouts, accidents, and even death). What you might not know is that the amount of alcohol considered a “binge” is probably less than you think. It’s defined as consuming four or more alcoholic drinks in about a two-hour period for females, and five or more for males.
“During a binge, you drink at a level that gets your blood alcohol to 0.08 percent and higher,” says Dr. Aaron White, senior scientific advisor to the National Institute on Alcohol Abuse and Alcoholism (NIAAA) in Washington, DC. “That’s also the level for which it is illegal for adults to drive a car.” Keep in mind, it’s illegal for anyone under 21 to drive a car with any alcohol in their system.
In short: Binge drinking sounds more intense than “heavy drinking” or “getting drunk,” but it’s essentially the same thing.
College students tend to vastly overestimate the extent of each other’s drinking. A lot more of you are sober than what you might think, according to the American College Health Association–National College Health Assessment, fall 2017.
College students who said they’d never used alcohol
College students who said they’d drunk alcohol within the last 30 days
Not as much as Hollywood movies might have you believe. Of 1,700 students who responded to a recent Student Health 101 survey:
- 13% self-identified as binge drinkers.
- 10% picked the correct definition of binge drinking from a list of six options.
When asked how often they drank four or more alcoholic drinks (women) or five or more (men) within two hours (the definition of binge drinking):
- 59% said never.
- 27% said once a month or less frequently.
- 14% said more frequently than once a month.
The impact on the young adult brain
While some heavy drinkers may appear clinically healthy, their brain chemistry may be compromised, especially in young adults.
That’s because the frontal lobe rapidly matures well into our twenties. This developmental period is critical for “functions such as information processing, decision-making, and impulse control, in part by improving communication between brain circuits,” says Dr. Yasmin Mashhoon, a neuroscientist at McLean Hospital, Belmont, Massachusetts, and Harvard Medical School.
The effect on our brains, grades, and safety
“Alcohol use in young drinkers is associated with a reduction in different domains of memory by up to 14 percent,” says Dr. Marisa Silveri, also a neuroscientist at McLean Hospital, and associate professor of psychiatry at Harvard Medical School.
The deficits affect working, verbal, and spatial memory. These effects linger for several days after drinking. “It could translate to the difference between an A and B or passing versus failing—or, more importantly, making safe choices versus failing to inhibit poor choices, like driving while intoxicated,” says Dr. Silveri.
Altered brain structure and function
Dr. Silveri and her colleagues studied and compared the brain structure of college-aged light and heavy drinkers (light being an average of 1.5 drinks per week, and heavy being almost 12 drinks per week). Among the heavy drinkers, researchers found:
- Cortical thickness, or outer brain volume, was significantly reduced.
- Impaired control, self-perception, and self-care; greater risk-taking; and worse academic or occupational consequences compared to the light drinkers.
- Lower levels of GABA (gamma-aminobutyric acid), the most important inhibitory (calming) neurotransmitter, in the frontal lobe. Deficiencies in GABA are associated with a range of psychiatric disorders, including depression, anxiety, and insomnia.
- Lower levels of the metabolite NAA (N-acetylaspartate). Deficiencies in NAA are associated with impaired neuronal health (brain cell integrity).
In another study by Harvard-McLean researchers, heavy drinkers recalled fewer words in a verbal test than light drinkers, showing possible learning differences between the groups.
Does heavy drinking cause these effects in the brain, or are people with these brain differences predisposed to heavy drinking? Animal studies show that binge drinking leads to comparable brain changes. Human studies to unravel cause and effect are in the planning stages.
Which strategies do students favor for safe alcohol consumption?
- Keep track of how many drinks you’re consuming. Wondering what counts as one drink? That’s 12 ounces of regular beer, 8 to 9 ounces of malt liquor, 5 ounces of table wine, or 1.5 ounces of hard spirits.
- Alternate non-alcoholic drinks (like water, soda, or juice) with alcoholic ones.
- Avoid drinking games.
- Determine in advance not to exceed a set number of drinks.
- Eat before and/or during drinking.
- Have a friend let you know when you’ve had enough.
- Pace alcoholic drinks to no more than one per hour.
- Stay with the same group of friends the entire time.
- Stick with only one kind of alcohol when drinking.
- Use a designated driver.
—From the American College Health Association–National College Health Assessment, fall 2017, and the National Institute of Alcohol Abuse and Alcoholism’s tips for cutting down on drinking.
In a recent Student Health 101 survey, 49 percent of 498 respondents said they thought getting drunk affected their academic performance over the next few days.
“I feel fatigue [and] mental sluggishness.”
—Derek*, fifth-year student, University of Kansas
“I have a much more difficult time connecting my thoughts.”
—Dina*, third-year student, Marian University, Wisconsin
“I don’t drink, but I have friends who do. After they do, they seem to have a hard time attending class and staying focused. They lose motivation to do anything.”
—Ariana*, third-year student, Utah State University
“My energy levels are low, and I feel less motivated to work or study.”
—Zachary*, fifth-year student, Metropolitan State University of Denver, Colorado
“After a night of drinking, I just want to lie on the couch and be lazy. I’m not motivated to work out or go to the grocery store to get ready for the week.”
—Lena*, third-year student, University of North Dakota
Dr. Yasmin Mashhoon, neuroscientist at McLean Hospital and Harvard Medical School, Massachusetts.
Dr. Marisa Silveri, neuroscientist, McLean Hospital, and associate professor of psychiatry at Harvard Medical School, Massachusetts.
Dr. Aaron White, senior scientific advisor to the National Institute on Alcohol Abuse and Alcoholism, Washington, DC.
American College Health Association. (2017). American College Health Association–National College Health Assessment II: Reference Group Executive Summary, Fall 2017. Hanover, MD: American College Health Association. Retrieved from https://www.acha.org/documents/ncha/NCHA-II_FALL_2017_REFERENCE_GROUP_EXECUTIVE_SUMMARY.pdf
Aware Awake Alive. (n.d.). Tools for universities and colleges: Quick facts. Retrieved from https://issuu.com/awareawakealive/docs/quick-facts/1?e=4770211/6217922
Kanny, D., Liu, Y., Brewer, R. D., Eke, P. I., et al. (2013). Vital signs: Binge drinking among women and high school girls. Morbidity and Mortality Weekly Report, 62(1), 9–13. Retrieved from https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6201a3.htm
Mashhoon, Y., Czerkawski, C., Crowley, D. J., Cohen-Gilbert, J. E., et al. (2014). Binge alcohol consumption in emerging adults: Anterior cingulate cortical “thinness” is associated with alcohol use patterns. Alcoholism: Clinical and Experimental Research, 38(7), 1955–1964.
National Institute of Alcohol Abuse and Alcoholism. (2004). NIAAA council approves definition of binge drinking. NIAAA Newsletter, 3(3). Bethesda, Maryland.
Silveri, M. M., Cohen-Gilbert, J. E., Crowley, D. J., Rosso, I. M., et al. (2014). Altered anterior cingulate neurochemistry in emerging adult binge drinkers with a history of alcohol-induced blackouts. Alcohol: Clinical and Experimental Research, 38(4), 969–979.
Silveri, M. M., Dager, A. D., Cohen-Gilbert, J. E., & Sneider, J. T. (2016). Neurobiological signatures associated with alcohol and drug use in the human adolescent brain. Neuroscience and Biobehavioral Reviews, 70, 244–259. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5494836/
Sneider, J. T., Cohen-Gilbert, J. E., Crowley, D. J., Paul, M. D., et al. (2013). Differential effects of binge drinking on learning and memory in emerging adults. Addiction: Research and Therapy, S7, 006.
Student Health 101 survey, December 2018.
Substance Abuse and Mental Health Services Administration. (2010). Results from the 2009 National Survey on Drug Use and Health; Volume 1. Summary of National Findings (Office of Applied Studies, NSDUH Series H-38A, HHS Publication No. SMA 104856 Findings). Rockville, Maryland.