Why you can be ‘blackout drunk’ and not even know it

Questions around Brett Kavanaugh’s drinking continue to swirl as the Supreme Court nominee faces allegations of sexual misconduct.

The testimony of Christine Blasey Ford — who says Kavanaugh sexually assaulted her when they were teenagers — during the recent Senate Judiciary Committee hearing put Kavanaugh’s alcohol consumption into the spotlight, as some have speculated that he could have been so drunk at the time of the alleged incident that he couldn’t remember his actions.

During the hearing, Kavanaugh stated he has not assaulted anyone, and denied ever drinking to the point of blacking out.

READ MORE: What does Brett Kavanaugh’s angry testimony say about gender and emotion?

A former Yale classmate of Kavanaugh’s said that he is “deeply troubled by what has been a blatant mischaracterization by Brett himself of his drinking at Yale,” and that Kavanaugh was “a frequent drinker, and a heavy drinker.”

So what does it mean to get blackout drunk, and how does serious intoxication affect your memory?

What does ‘blackout drunk’ mean

Contrary to what many people think, getting blackout drunk does not necessarily mean you’ve passed out or are unconscious. Instead, it refers to an inability to recall certain memories or events that occurred during a period of drinking, said Dr. Jonathan Bertram, an addictions physician at Toronto’s Centre for Addiction and Mental Health (CAMH).

READ MORE: Health Canada failing to address dangers of growing vaping ‘epidemic’: Cancer society

A person who is experiencing a blackout may still be socializing and engaging in conversations with others, and are unaware their memories may be lost, so to speak. Some people may even appear relatively OK, making it hard for others to detect their level of intoxication.

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Why do some people black out when drinking?

Research shows that alcohol causes memory impairment. Alcohol affects someone’s ability to form new memories while they’re intoxicated, but does not typically erase memories formed before intoxication, another study found.

Alcohol-related blackouts may be complete, meaning the person doesn’t remember anything past a certain point or their memory is fragmented, meaning they can recall aspects of what happened while they were drunk.

Experts aren’t entirely sure why some people experience blackouts and others do not, Bertram said. But there’s research that suggests regular blackouts might indicate a problem with alcohol use.

READ MORE: Are there benefits to doing a liver cleanse?

What happens to your memory when you black out?

Our memories are mediated by the subconscious part of our brain, Bertram said. When someone is drinking significant amounts of alcohol, the way their brain functions is affected.

Early studies on alcohol-related blackouts in alcoholics found that subjects were “able to keep information active in short-term memory for at least a few seconds,” meaning they could often carry on conversations and engage in other complicated behaviours. But information related to these events was not transferred into long-term memory storage, meaning people had no recollection of what happened during their blackout.

How common are drinking-induced blackouts?

One study revealed that 66 per cent of university students reported experiencing blackouts at some point. Men with a maternal family history of alcohol problems were more likely to black out, the study found.

Bertram said that if a person blacks out it does not necessarily mean they have a problem with drinking, but blackouts are commonly seen in people who do have issues with alcohol.

READ MORE: Excessive alcohol consumption killed 3 million in 2016: WHO

“At the Addictions Medicine Service at CAMH, people are generally going to — if not always — seek help… because there are problems with their alcohol,” Bertram said. “That doesn’t always mean that they have an addiction, but it does mean there have been consequences associated with their drinking. And often, but not always, blacking out is part of their history or their pattern.”

“Blackouts are not indicative or equivocal to addiction, nor is it equivocal to a problem with use, but it might indicate those two things.”

Laura.Hensley@globalnews.ca