Binge Drinking in Adolescence May Lead to Mental Health Problems in Adulthood
By exposing adolescent rats to amounts of alcohol that were comparable to binge drinking in humans, the researchers found that the alcohol consumption permanently changed the system that produces hormones in response to stress, which can lead to behavioral or mood disorders later in adulthood.
Toni Pak, PhD, lead author of the study and an assistant professor in the Department of Cell and Molecular Physiology at Loyola University Chicago Stritch School of Medicine, said that while animal studies don’t directly translate to humans, the findings suggest that binge drinking in adolescence could be associated with mental health problems in adulthood. Pak added that drinking at a young age could permanently alter connections in the brain that ensure healthy brain function in adulthood.
Binge drinking is defined as at least four drinks in one sitting for a woman and at least five drinks for a man. Heavy binge drinkers have 10 to 15 drinks in one sitting. According to the Substance Abuse and Mental Health Services Administration, 36 percent of people between the ages of 18 and 20 report binge drinking at least once in the past 30 days. Binge drinking usually starts around age 13 and peaks between 18 to 22 before gradually decreasing.
Humans and rats both produce the stress hormone cortisol (in rats its called corticosterone) in response to stress. When presented with a stressful situation, cortisol is produced, providing a burst of adrenaline and a lower sensitivity to pain, and suppressing functions that aren’t immediately necessary, such as digestion. Chronic exposure to cortisol and other stress hormones has been associated with depression and cardiovascular disease.
In the study, rats were injected with an amount of alcohol equivalent to binge drinking for three days, followed by two days off, and were then injected with binge-drinking amounts of alcohol for another three days. A control group of rats were injected with saline.
When the rats became young adults (one month later), they were exposed to saline injections, a one-time alcohol injection, or the binging pattern of alcohol injections. Because alcohol is a form of stress, the rats that had a one-time injection or the binging injection produced higher levels of the corticosterone stress hormone.
Rats that were injected with any amount of alcohol during adolescence had a significantly larger spike in corticosterone when they were injected with alcohol in adulthood, and they had a lower base level of the stress hormone than rats that didn’t receive alcohol. This suggests that consuming alcohol during adolescence alters the brain’s system that controls the production of stress hormones.
Source: Science Daily, Binge Drinking Teens May Be Risking Future Depression, November 15, 2010