Most of us remember what happened the last time we had a drink. For most, a drink is a normal, non-problematic part of socializing and celebrating, not something that leaves us fuzzy, wondering where we’ve been and what we’ve done. However, a night of heavy drinking can include big blank spots in memory. That's when alcohol takes over and effectively incapacitates the brain's memory functions. This is known as a blackout and is symptomatic of a drinking problem. This page is about how alcohol affects memory and its qualities as a neurotoxin.
What is Memory?
The mechanisms for human memory are quite fascinating. Essentially, memory breaks down into two types, commonly called short-term and long-term. Short-term memory refers to new information that we need for daily activities, but which may also be encoded for later retrieval. For instance, we need to know where we parked the car, whether we fed the dog this morning, and what we learned in a meeting. Long-term memory refers to memories in permanent storage. Generally, we think of long-term memories as being those from childhood, last year's sports scores, and yesterday's important meeting.
Long-term memory is governed by the Hippocampus, a part of our medial temporal lobe. Its precise role is still a matter of scientific study and discussion, but we know that damage to the hippocampus is a large part of Alzheimer's disease. When the disease overtakes the Hippocampus, patients forget vital information, including their own identity. Alcohol also damages the Hippocampus and chronic heavy drinkers are prone to losing long-term memories.
What Types of Memory Does Alcohol Affect?
- Short-term:
Comprised of new information and temporary facts such as where you left your car keys, a new person's name, a grocery list, or even an entire evening’s worth of what you did, said, and saw. Too much alcohol in an evening can eradicate your short-term memory in a blackout state. - Long-term:
Initially encoded into short-term memory before being moved to long-term, these memories are stored for the long-haul. Long-term memories may be as important as childhood memories or as mundane as last year's grocery list. Since alcohol damages the hippocampus, long-term memories are jeopardized by heavy drinking, especially chronic excessive drinking. - Episodic Memory:
These memories are more than facts but relate to entire episodes or events. Episodic memories are tied to emotions. When you blackout from excessive drinking you cease to create new episodic memories. Further, since alcohol suppresses emotions, even so-called moderate drinking may impair how you create these memories. - Semantic Memory:
These are the Joe Friday of memory, they're just the facts. You may rely on semantic memory to pass a test and to remember a password. It's likely that drinking will impair your ability to create semantic memories. Thus, you should wait to learn new material until you've sobered up. - Implicit Memory:
These memories are often considered intuitive and don't require any additional thought. They include things such as how to ride a bike, where to find your socks, or an internal map to your neighborhood. Alcohol has been found not to impact these memories, which is part of why people in a blackout may appear to be functioning normally.
Factors to Consider
Alcoholism is a progressive, degenerative disease. Not everyone will progress to the stages of Korsakoff Syndrome and wet brain, but each drink negatively impacts the nervous system, as well as every other system in the body. There are several factors that can exacerbate the problem, but note that the problems with alcohol always increase, they never abate, unless you choose to stop drinking altogether.
The factors you need to consider include your age, sex, and genetics. Though there's no safe age for drinking, those in their early adulthood may be best able to cope with alcohol. Males are even better able to handle the toxic effects, as women tend to have a lower tolerance. Family history and genetics also impact how one copes with alcohol. Those with a family history of alcoholism or addiction are encouraged to abstain.
Yet another key indicator for alcohol abuse, and the neurological problems that result, is trauma. Those who have experienced great trauma may find that the numbing effect of alcohol helps them escape their terrifying memories of the event(s). In this way, some try to trigger the memory problems alcohol creates so as to escape deep personal pain. However, as a side effect of alcohol is a “down” effect, alcohol tends to only compound those problems in the long-run and can trigger a cycle of increasing drunkenness. If you've been deeply hurt, seek professional help rather than taking a drink.
How Does Alcohol Affect Memory?
Immediate Effects
One of the most dramatic and evident effects alcohol has on memory is the blackout state. During a blackout, you might walk and talk just as though you were sober, or tipsy. However, your hippocampus will not be storing your experiences for later retrieval. It's likely that you won't have much, if any, short term memory of things that have just occurred. Since a blackout has such a dramatic impact on memory, you are vulnerable to tremendous danger in that state. In effect, a blackout is a sort of voluntary case of amnesia.
A blackout state eliminates access to a host of general memories. At best, you’ll have your factual, semantic memories as well as some implicit memories. Thus, with your long-term, short-term, and episodic memories inaccessible you will have lost much of your personal identity and personality. Some describe a blackout state as being on autopilot, while they are asleep at the wheel.
Long-term Effects
Over time, chronic heavy drinking leads to dramatic memory problems. Alcohol has a deleterious effect on brain cells and, when it erodes the hippocampus, you soon lose long-term memories. This may creep up on you slowly, over time. When you are a chronic, heavy drinker, you may become accustomed to the memory deficits you incur while drinking. Tragically you may someday suddenly realize that you've done irreparable harm to your memory.
You might also lose the ability to store short-term memories even when you're between benders. This can result in problems at work and at home. Though you might laugh this off as forgetfulness, such lapses can be an indication that you have done permanent, physical damage to your brain.
Permanent Damage
Though alcohol is pervasive throughout our society, it is a neurotoxin that can do permanent damage when abused. One of the more extreme outcomes is Wernicke-Korsakoff Syndrome, commonly known as Korsakoff Syndrome, or wet brain. This neurological disease most often arises in the end stages of alcoholism as the result of a vitamin B1/thiamine deficiency.
A precursor to Korsakoff Syndrome is Wernicke Encephalopathy, which is diagnosed from symptoms such as confusion, double vision, difficulty walking, and rapid heartbeat. When left untreated, those symptoms will start to abate, paving the way for dramatic short-term memory loss in which you will forget things minutes after learning them. Long-term memory loss is also a common feature of Korsakoff Syndrome.
These problems can be abated somewhat if you take vitamin B1/thiamine. In fact, some major beer makers recognized this problem and supplement their alcoholic beverages with that vitamin.
Treatment
If Wernicke Encephalopathy or other memory deficits from alcohol are caught in a timely fashion, they can often be treated. Doctors can prescribe large doses of thiamine (vitamin B1) in pill or injection form. However, as with many neurological diseases, treatment outcomes are highly variable. Much will depend on how far the disease has advanced and other factors such as age, genetics, and overall health. If, however, the disease has progressed to Korsakoff Syndrome, the prognosis is bleak. Though a full 25% eventually recover, 50% show some signs of lesser recovery, and 25% never improve.
The key to recovery from either disease is complete abstention from alcohol. If, however, an alcoholic decides to drink after the doctor declares a complete remission, they are playing with fire. More often than not, alcoholics of this extreme variety are known to revert to their former condition, as they have proven that moderate drinking is not for them.
Avoiding Memory Loss from Alcohol
The best way to avoid memory loss, and other disorders that arise from drinking alcohol, is to abstain from alcohol altogether. Science is increasingly showing that there is no truly safe dose of alcohol, especially when imbibed on a regular, habitual basis. However, moderate users typically avoid memory problems such as blackouts and tend to lead relatively healthy lives.
Moderate users should be vigilant and take note, if not alarm, when their drinking increases in volume and/or frequency. If drinking alcohol results in any physical symptoms whatsoever, then there is likely to be a problem. This includes hangovers and any gastrointestinal problems that follow a night of drinking. If one's drinking escalates to the point where it is interfering with a healthy diet, a healthy lifestyle, or any other aspect of your day-to-day life, it is time to seek help. Though the dire outcomes related to Korsakoff Syndrome are rare, they are very real and there is no reason to tempt that fate.