Alcohol consumption harms normal bodily functions and throws off our judgement and motor skills. Heavy drinking can negatively effect cognitive abilities.  

Memory is one of the cognitive functions that becomes less effective when you or a loved one is drinking a lot. Loss of memory can result from both short and long term heavy drinking, and can be experienced both immediately following a heavy drinking episode, or over a longer period of time if there is a pattern of heavy drinking. 

We have two types of memory by which our lives’ experiences are sorted: retrospective memory and prospective memory. Retrospective memory is our long term memory. This is where events and experiences from throughout our lives are stored, and where we can retain and eventually retrieve those memories and pieces of information. Prospective memory is our short term memory. This is where we store our day to day experiences, as well as the information we learn or come across.

Short Term Memory Loss

There are a few ways heavy drinkers can experience short term memory loss from consuming alcohol. It is frequently a consequence of binge drinking. Binge drinking is the consumption of five or more standard drinks for males, or four or more standard drinks for females, over the course of approximately two hours. It can lead to memory blackout or partial blackout experiences, as well as impairment of overall short-term memory. 

There are two forms of alcohol induced blackouts. One such type is called an 'en bloc' blackout. This is a total blackout, or loss of memory, of a drinking episode. A sometimes partial blackout of a drinking episode is known as a 'fragmentary' blackout. In the case of a fragmentary blackout, some parts of the drinking episode are completely forgotten, while others are not. Both can happen to anyone after consuming a certain amount of drinks.

Alcohol is the most commonly abused drug in the US. According to the National Institute of Alcohol Abuse and Alcoholism, in 2015, nearly 27 percent of people 18 and older reported binge-drinking in the past month.  The most common age group of binge drinkers are those between the ages of 18 and 34. In this same year, seven percent reported taking part in heavy drinking throughout the past month. For both heavy and moderate drinkers, gender, weight and alcohol tolerance all play a role in determining the likelihood of a blackout.

Heavy drinkers experiencing blackouts are at risk of engaging in dangerous behaviors and situations. During episodes of binge-drinking, drinkers may have put themselves in danger physically, sexually or mentally. Being unable to recall these experiences puts heavy drinkers at risk of not getting the medical attention they may need. Such medical attention may include help for instances of injury or STD testing. 

Alcohol plays a role in 50 percent of all trauma injuries and assaults, as well as 40 percent of all fatal driving accidents, fatal falls and suicides. It also plays a role in 6 percent of all fatal burn injuries, drownings and homicides. In the case of heavy drinking, or binge-drinking, comes the risk of losing memory of such accidents. This puts an even greater risk to those involved. It also puts emotional, legal and financial burdens on the loved ones of the participants and victims.

A heavy drinking episode would mean that a man is consuming 5 or more drinks in one sitting, and a woman is consuming 4 or more drinks in one sitting. Men that drink equal to or greater than 21 drinks per week and women who drink equal to or greater than 14 drinks per week puts them in the “at-risk” category of drinking, which means that both their memories are at risk of being weakened or lost, and they are likely experiencing symptoms of Alcohol Use Disorder (AUD). If you or someone you know is drinking heavily or binge-drinking, consider encouraging them to become a research volunteer with us to help Scripps Scientists discover new medications aimed at reducing the urge to drink.

Long Term Memory Loss

Aside from blackouts when binge-drinking, long term memory can also be negatively impacted from heavy drinking. Alcohol damages the hippocampus, located in the brain. This part of the brain plays a critical role in creating memories and learning. The brain becomes less able to transfer memories from short-term to long-term storage when the hippocampus is damaged.

Most of any noticeable memory loss comes as an instant effect of heavy drinking, or an episode of binge-drinking. Heavy drinking changes the size of the brain cells responsible for the process of developing memories. It can also cause the hippocampus to shrink. This is why the brain struggles to form memories when drinking heavily.

Heavy drinking also puts consumers at risk of Wernicke-Korsakoff Syndrome (WKS). Alcoholism is the leading cause of developing this brain disorder. WKS is caused by a lack of vitamin-B1. This is often experienced by heavy drinkers because high alcohol intake often leads to a poor diet or forms of malnutrition. However, alcohol even prevents vitamin-B1 from being absorbed and stored in the body.

Wernicke’s Disease and Korsakoff syndrome, the two elements of WKS, have symptoms of their own. However, the symptoms of WKS as a syndrome of these combined diseases include amnesia of events after the onset of the syndrome, difficulty understanding the meaning of information, hallucinations and exaggerated storytelling. Those with WKS struggle to create long term memory. 

If you are a frequent drinker with no intention of quitting alcohol, call to find out if you’re eligible to volunteer for a 5-week, paid research study that aims to develop new medications for those suffering from alcohol use disorder.