College, minus the memories: The science behind blacking out

Drinking is nothing new on college campuses. It's also an activity students rarely hide, except from local law enforcement, RAs and maybe parents. Drinking to blackout, or to bring on total memory loss for periods of time, is also nothing new, but it's becoming increasingly popular among students -- despite the fact that many don't what it really means to black out.

Rose Marie Ward, a kinesiology and health professor, said this phenomenon is especially troubling at Miami. According to Ward, 50 percent of its student population report experiencing alcohol-induced memory loss in the past year.

"Drinking to blackout, or to pass out, is not what alcohol is for," Ward said. "We have these expectations for what alcohol can do for us, and I think we need to check on that and what we think is normative behavior."

Of course, no singular cause of students' excessive drinking can be pinpointed, but psychology professor Matthew McMurray said blame can usually be attributed to social pressures, mental illness like depression or anxiety and a genetic predisposition to drink more.

Many college students also don't intend to black out when they drink. Every person's limit is different, but people often feel compelled to keep up with their more-alcohol-tolerant friends and push these boundaries.

"I'm not saying all students drink this way," Ward said. "But we have a subset of people here that are drinking in very high-risk situations and saying and doing things [that] they don't remember."

Drinking to the point of blackout is risky enough on its own; a blood alcohol level of .2, at which most people start to experience memory loss, veers close to the point of alcohol poisoning and loss of consciousness altogether.

But alcohol isn't the only aspect of this phenomenon that can haunt people after the blackouts are over, psychology professor Matthew McMurray explained.

"It's not just that you're blacked out," McMurray said. "It's also that you're impaired in the normal way that you're impaired when you're drinking in a non-blackout state. Those two things overlap at the same time."

Memory is controlled by the brain's hippocampus, which can be severely impaired by excessive amounts of alcohol. Heavy drinking prevents short-term memories from becoming long-term ones, resulting in what many students call "blacking."

"People could interact with you in ways that you wouldn't find appropriate sober, so we do see higher rates of sexual assault, higher rates of violence during blackout periods," McMurray said. "Students have no recollection of those things happening, so it's kind of like your long-term memory shuts down."

According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), females are at a higher risk for blacking out than males, because of males, on average, have a higher alcohol tolerance. The NIAAA also noted in a 2004 publication that many blackouts occur due to students' mixing drugs like Valium or marijuana, "which are already capable of producing amnesia on their own," with alcohol.

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The effects of blackout drinking also reach farther than waking up on Saturday mornings with no recollection of the night before. Since it requires heavy drinking, those who engage often can rapidly develop a higher tolerance for alcohol and, in turn, neurotoxicity (which damages nerve tissue) and potentially the death of brain cells.

"That drive, that risk, how scary is it that you will be doing things, saying things, being out there with no memory of what you did?" Ward said. "No memory of peeing on St. Mary's, no memory of beating someone up, no memory of what you ate . . . why would you do that"