Alcohol and Memory Loss: Short- and Long-Term Effects

Alcohol can negatively impact brain function and memory in the short term and long term. When someone drinks too much, alcohol can inhibit the brain’s ability to store long-term memories. Often called blackouts, excess alcohol can create blank spaces or gaps in an individual’s memory. Over time, chronic alcohol misuse can lead to more serious long-term memory loss by causing complications like Wernicke-Korsakoff syndrome. 

The adverse effects of prolonged and excessive alcohol use are well-documented and include liver damage, cardiovascular conditions and many other negative effects. Besides these effects, chronic alcohol use can also directly or indirectly cause brain damage and result in alcohol-induced dementia. Alcohol-induced dementia involves impaired cognitive functioning that is permanent, affecting you for the rest of your life.

The memory and learning impairment caused by chronic alcohol intake may not be reversible. Similarly, acute alcohol intoxication also results in an impaired ability to form new memories, referred to as alcohol-induced blackouts. However, unlike chronic alcohol intake, anterograde amnesia (the inability to create new memories) caused by alcohol intoxication only affects your memory for brief periods.

How Alcohol Causes Memory Loss

Alcohol can lead to memory loss in a wide variety of ways. In the short term, memory loss is caused by its effects on the hippocampus, a vital area of the brain responsible for forming and retrieving memories. When you drink, it disrupts the hippocampus’s function, hindering its ability to consolidate new memories. As a result, you may struggle to form new memories while drunk. You may also have blank spots where memories should be. This phenomenon is often referred to as “blackouts.” 

Chronic, excessive drinking can also lead to lasting brain damage, which can develop into serious brain conditions. Wernicke-Korsakoff syndrome is one such condition that can lead to permanent memory loss. It is caused by a severe deficiency of thiamine (vitamin B1). This nutritional deficiency is almost always associated with long-term alcohol misuse.

Alcohol can also greatly increase your risk of head trauma or injury that can affect your memory. As many as 50% of people who misuse alcohol will experience head trauma at some point.

Short-Term Memory Loss from Alcohol

Even small amounts of alcohol can produce memory impairments. The degree of impairment increases along with the level of alcohol intake. Despite their inability to form new memories, short-term memory function still works. This makes it possible to socialize or engage in complex activities like driving a car but not remember it later. Driving while intoxicated is illegal and not recommended. 

Signs of Alcohol-Induced Blackout (Amnesia)

An alcohol-induced blackout combined with other alcohol intoxication symptoms can result in risky and reckless behaviors. It is typically impossible to tell if someone is having a blackout, as they can still function normally. Alcohol-induced blackouts are often only recognized after the fact due to an inability to remember things. It may be possible to tell if someone is blacking out by their inability to remember recent events that happened more than a few minutes ago.  

Alcohol-induced amnesia occurs from high levels of alcohol in the body. It is often accompanied by:

• Impaired ability to recall previously acquired information (retrograde amnesia)
• Impaired ability to form new memories (anterograde amnesia)
• Difficulty perceiving the spatial relationship of objects
• Deficits in executive functioning involving complex cognitive processes like planning, thinking and decision-making

Alcohol-Induced Blackouts

The impaired ability to form new memories (anterograde amnesia) is referred to as an alcohol-induced blackout.

With normal memory function, information is first acquired from the environment and stored in short-term memory. It is then transferred to long-term memory as it is processed in the hippocampus.

Short-term memory has a limited storage capacity. Thus, newly acquired information persists in short-term memory only for a few minutes (5 to 30 minutes). Long-term memory has a much greater capacity. Information may be stored there for anywhere between a few days to decades.

Rapid intake of high levels of alcohol disrupts the transfer of information from short-term memory to long-term memory. During a blackout, individuals can retain new information in their short-term memory for a few minutes in the absence of distractions. This enables individuals to engage in social activities, have conversations and even drive a vehicle. Similarly, the memories formed before and after the blackout also remain intact.

The memory loss during a blackout impacts the ability to store long-term memories. Therefore, memory loss may be partial or complete. In the case of partial or fragmentary blackouts, individuals can remember some information regarding the events during the blackout episode when prompted with information. When a complete blackout occurs, there is no long-term memory stored. Therefore, the entire evening could potentially be forgotten.

Long-Term Memory Loss from Alcohol

In addition to blackouts and temporary amnesia, excessive drinking over extended periods can seriously impair cognitive function. Over time, alcohol’s impact on the brain can even lead to persistent, irreversible deficits in memory. A thiamine deficiency often causes these cognitive impairments. The brain requires thiamine (vitamin B1) for proper functioning, but alcohol, over time, can inhibit the body from absorbing thiamine. 

Wernicke’s Encephalopathy

Wernicke’s encephalopathy is an acute and life-threatening condition caused by thiamine deficiency. Wernicke’s encephalopathy is characterized by symptoms that include:

• Impairment of nerves that control eye movements 
• Impaired motor coordination 
• Changes in mental status, such as confusion, apathy and reduced speech

Korsakoff’s Psychosis

If untreated, Wernicke’s encephalopathy may progress to Korsakoff’s psychosis, which is a chronic and debilitating condition. Korsakoff’s psychosis is characterized by difficulty retrieving existing memories (retrograde amnesia) accompanied by an impaired ability to form new memories (anterograde amnesia). Other symptoms of Korsakoff’s psychosis may include:

• Hallucinations
• Agitation
• Confabulation (unintentionally making up stories to fill in memory gaps)

Wernicke-Korsakoff Syndrome

Nearly 80% of Wernicke’s encephalopathy cases progress to Korsakoff’s psychosis. Due to their co-occurrence as part of a continuing progression of the same process, these conditions combined are referred to as Wernicke-Korsakoff syndrome. Most individuals with Wernicke-Korsakoff syndrome will show at least some degree of persistent deficits in learning and memory.

Symptoms often include:

• Double vision
• Paralysis of certain eye muscles
• Inability to walk or maintain footing
• Rapid heartbeat
• Loss of consciousness

Alcohol-Induced Dementia

Alcohol-induced dementia is not technically a medical term but is often used to describe dementia-like symptoms that occur due to alcohol use. Korsakoff syndrome, the permanent component of Wernicke-Korsakoff syndrome, is the most common cause of alcohol-induced dementia. Someone with this condition will be unable to form new memories and will have large gaps in the memory prior to developing it. Their subconscious will fill these gaps with made-up memories called confabulations.

Alcohol-induced dementia is serious. Memory loss can result in forgetting how to do important tasks, like eating, using money, or dressing yourself. Many people with alcohol-induced dementia require constant care for the rest of their lives.

Prevention of Alcohol-Related Memory Loss

Acute and chronic alcohol intake in excessive amounts is associated with adverse physical and mental health effects. Hence, it is advisable to limit the intake of alcohol to a drink or two and avoid heavy alcohol use. Guidelines from the Center for Disease Control recommend limiting alcohol intake to one drink for women and two for men in one sitting.

Restricting alcohol intake was previously believed to protect cognitive function. However, this belief is no longer held by most medical professionals. Moderate-to-heavy alcohol use has always been linked to a higher risk of negative outcomes. Even occasional intoxication with alcohol may lead to a blackout and requires social drinkers to be vigilant about such consequences.

Drinking alcohol in excess isn’t the only factor influencing the risk of amnesia. Behaviors like chugging alcohol and drinking on an empty stomach can also lead to high alcohol absorption and blackouts. Therefore, restricting the number of alcoholic drinks is just as important as pacing yourself while drinking. Caution should be exercised in the case of drinks with high alcohol content. Staying hydrated and having a meal before drinking can also help prevent alcohol-induced blackouts.

The Impact of Alcohol and Memory Loss

Alcohol use can lead to both one-time blackouts and long-term memory loss that mimics dementia. Blackouts may seem minor. However, people have gone to jail for crimes they can’t remember committing due to blacking out. Blackouts can also damage relationships in ways the person will never be able to recall. Blackouts can be devastating, whether personally or legally.

Alcohol-induced dementia can have an even greater impact. You may forget family members or lose your ability to learn and enjoy life. At this level, forming and maintaining relationships can become almost impossible. Ultimately, this deprives you and your loved ones of the ability to enjoy these important relationships.

Help for Alcohol Abuse and Addiction

The best way to manage alcohol-related memory loss is to stop it from occurring in the first place. Stopping memory loss by controlling your alcohol use is vital. In the end, there is no way to get memories back once they’re gone. Cutting back or stopping alcohol altogether is the best way to prevent memory loss and protect your brain’s health.

If you or a loved one struggles with alcohol abuse or addiction, contact The Recovery Village Palm Beach at Baptist Health to speak with a Recovery Advocate about how addiction treatment can help. Take the first step toward a healthier future and call today.