How Does Alcohol Alter Memory?
Key takeaways:
Alcohol affects the way memories are stored in your brain, which can make it difficult to remember what occurred while you were drinking.
Drinking large amounts of alcohol can lead to blackouts, which are severe memory lapses that happen when blood alcohol concentration is high.
Long-term heavy alcohol use can increase the risk of alcohol-related dementia. This is a serious condition that may be permanent if it’s not properly treated.
Table of contents
Alcohol can have serious effects on your health and well-being, especially if you drink heavily. Heavy drinking increases the risk of several health issues and development of alcohol use disorder. It can affect most organs in the body, including the brain.
One major effect of alcohol is the risk of memory problems. And heavy use can also lead to dementia. Here we’ll review how alcohol affects memory and whether the effects are reversible.
Can alcohol cause memory loss?
Alcohol affects many different organs in the body, including the brain. Alcohol can affect memory shortly after drinking and after long-term use. This is because it can affect memory consolidation, which is the process of transferring memories from short- to long-term storage.
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If you drink a lot of alcohol at one time and become intoxicated, you may experience a blackout. A blackout occurs when a person drinks so much alcohol that it impacts memory consolidation. The person experiences a gap in memory that may last minutes to hours.
There are two types of blackouts:
En bloc blackouts are ones where absolutely no short-term memories are transferred to long-term storage. You wouldn’t be able to recall any details of what happened while you were drinking, even if your friends try to remind you.
Fragmentary blackouts are ones where you have some “spotty” memories while drinking but cannot recall the full event. In other words, some short-term memories (but not all) are transferred to long-term storage. You may be able to recall details of what happened only after others remind you.
Blackouts are dangerous. When you black out, you may put yourself in risky situations or have slower reaction times.
How much alcohol does it take to impair memory?
The amount of alcohol that it takes to affect memory depends on the person. Blackouts can happen when a person’s blood alcohol concentration (BAC) approaches 0.16. This means that 0.16% of the person’s blood volume is alcohol.
The amount of alcohol that it takes to reach a certain BAC varies from person to person.
Alcohol affects your memories, as well as your emotions. Learn about the ways alcohol can affect your mood.
Does alcohol help your anxiety or make it worse? Our experts explore the link between alcohol and anxiety.
What happens when you mix alcohol and caffeine? We explain the results, so you don’t have to find out for yourself.
Certain factors can increase the chances of a blackout, including:
Drinking a large amount of alcohol in a short period of time
Drinking on an empty stomach
Being female
Having a lower body weight
Mixing alcohol with sleep or anxiety medications
Women are at higher risk of experiencing blackouts than men. This is due to the differences in how women metabolize — or break down — alcohol.
Can alcohol cause dementia?
Dementia is a term that describes impairments in memory, thinking, and overall functioning. There are several types of dementia. Chronic alcohol use can lead to permanent brain damage and memory impairments, known as alcohol-related dementia. People with this condition experience memory loss and difficulty forming new memories.
Experts believe a few factors lead to alcohol-related dementia:
Alcohol and its byproducts are directly toxic to the nervous system.
Heavy alcohol use leads to a thiamine (vitamin B1) deficiency, which may play a role (more on this below). People with alcohol use disorder are at higher risk of a thiamine deficiency. This is because heavy alcohol use affects how your body metabolizes the vitamin.
Heavy alcohol use also increases the risk of other conditions that affect the brain, such as vascular changes, liver disease, and brain injury.
The amount of alcohol (or years of use) it takes to develop alcohol-related dementia is unknown. Often studies define “heavy” drinking differently, making comparisons difficult. And many studies don’t have a good representative sample of heavy drinkers. Experts haven’t identified a threshold at which drinking irreversibly affects memory.
Symptoms of alcohol-related dementia
Wernicke-Korsakoff syndrome is one type of alcohol-related dementia. You may have heard of it as “wet brain,” although this isn’t a medical term. It’s due to thiamine deficiency.
There are two stages of Wernicke-Korsakoff syndrome: Wernicke encephalopathy and Korsakoff syndrome.
Wernicke encephalopathy
The primary symptoms are:
Confusion
Visual problems due to abnormal eye movements
Lack of coordination
Memory impairment
Coma
Korsakoff syndrome
Wernicke encephalopathy can progress into Korsakoff syndrome if not treated with thiamine replacement. The major hallmark is irreversible loss of memories, which can be profound. Symptoms include:
Memory loss
Difficulty acquiring new memories
Problems with critical thinking and decision-making
Confabulation, or fabricating events and details
Apathy, or lack of concern about most things
Is memory loss from alcohol reversible?
The long-term effects of alcohol on the brain may be permanent, especially in severe cases. This is because alcohol damages your DNA and neurons directly. You can prevent further damage by not drinking alcohol. Also, getting treatment in the early stages of alcohol-related dementia may help.
Wernicke encephalopathy can be reversed if treated with intravenous (IV) thiamine for at least a few days. Without this treatment, Wernicke encephalopathy can progress to Korsakoff syndrome, which is not reversible. Researchers have not been able to find any effective medications, either, but cognitive rehabilitation may help.
Does quitting alcohol improve your memory?
Quitting alcohol is the best way to prevent further memory loss for those who already have it.
And there’s some research to suggest that quitting can eventually help some brain functions recover, including memory. Generally, the longer you stay away from alcohol, the greater the chance that your brain functioning improves. But this can take time and patience, and it may vary from person to person.
Alcohol withdrawal can be dangerous. So be sure to get help if you’re thinking about quitting.
How to prevent memory loss when drinking
The best way to prevent memory loss — or any bad effects — from drinking is to abstain. If you are of legal age and choose to drink, be mindful of what and how much you’re drinking. Here are some tips to keep in mind:
Check your medication list first to see if it’s safe.
Don’t drink on an empty stomach.
Don’t try to “keep up” with your friends.
Drink plenty of water.
Have a designated driver or plans for not driving.
Frequently asked questions
Both alcohol and cannabis (marijuana) are known to affect memory. Cannabis contains THC, which attaches to receptors in areas of the brain that are involved in memory. The effects of cannabis on memory may be greater with more frequent use, higher quantities, and starting at an earlier age. That said, the long-term effects of cannabis on memory are still unknown, so more research is needed to understand if it’s better or worse than alcohol.
The life expectancy for people with alcohol-related dementia is shorter than those without. One study found people with alcohol-related dementia to be five times more likely to die. Heavy alcohol use can contribute to other conditions, such as cardiovascular disease and cancer, but it can also lead to direct organ damage.
According to the National Institute on Alcohol Abuse and Alcoholism, heavy drinking is defined as:
5 or more standard drinks on a given day for men (or more than 15 in a week)
4 or more standard drinks on a given day for women (or more than 8 in a week)
When it comes to a standard drink, the type of alcohol and serving size matters. Different types of alcoholic beverages contain different amounts of alcohol. A standard drink is defined as:
5 oz of wine
12 oz of beer
8 oz to 10 oz of malt liquor or hard seltzer
1.5 oz of distilled spirits
The bottom line
Alcohol affects the ability to form long-term memories. Heavy alcohol use over time can lead to alcohol-related dementia. This can cause memory loss and difficulty forming new memories. Not drinking alcohol is the best way to avoid memory problems linked to drinking. However, if you do choose to drink, stick to moderate drinking limits and avoid heavy drinking.
Why trust our experts?
References
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Palm, A., et al. (2022). Incidence and mortality of alcohol‐related dementia and Wernicke‐Korsakoff syndrome: A nationwide register study. International Journal of Geriatric Psychiatry.
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Smith, H., et al. (2020). Thiamine dosing for the treatment of alcohol-induced Wernicke’s encephalopathy: A review of the literature. Journal of Pharmacy Technology.
If you or someone you know struggles with substance use, help is available. Call SAMHSA’s National Helpline at 1-800-662-4357 to learn about resources in your area.
