Impact of Alcoholism
May 1, 2012
UnityPoint Health - Des Moines
Decades of research have shown that alcohol severely damages the brain, causing blurred vision, slurred speech, slowed reaction times and impaired memory. Alcoholism causes cognitive deficits in 50 to 80 percent of alcoholics. Interestingly, memory loss worsens when an alcoholic stops after a prolonged period of drinking, whether that involves binge drinking or continuous drinking as seen in chronic alcoholics.
Repeated periods of alcohol use followed by withdrawal seem to have the most significant impact on memory. Withdrawal isn't limited to severe symptoms such as seizures associated with the sudden cessation of alcohol use after an extended period of drinking. It can be as subtle as the sweatiness and shakiness people often feel when they wake up after a night of drinking. If someone drinks every day and stops every night, they are going to experience withdrawal every morning. And that's the kind of withdrawal that injures memory.
So when alcoholics say, "I don't think my memory was this bad before I stopped drinking," they are observing a genuine scientific phenomenon. Stopping drinking causes a toxic reaction in the brain that significantly worsens memory deficits. Of course, the answer is not to continue drinking. Research also shows that medication, alcohol addiction treatment and 12-Step recovery can minimize the effects of drinking.
The Impact of Alcoholism on Memory
As a result of animal studies, we know that alcohol-related memory impairments appear to be related to changes in the gray matter of the brain as well as changes in hippocampal volume, a structure specifically associated with memory.
When rats are placed in a cage with objects they've never seen before, they are attracted to the novelty. They sniff and paw at the objects to determine if they are of any interest. Once they learn what the object is, they lose interest. This is called object recognition.
When an animal is trained in a T-maze, it is taught to run down a structure shaped like a T. On one side there's a reward, and on the other side there's nothing. After a short time, the arm that has nothing is blocked so it can only go one way, and it goes directly to the food reward.
Ordinarily, if the block is removed, the animal will learn to check which side has the food. It will un-learn this pattern of always going to the side that had the food originally, check out the environment, and learn to go to whichever side currently has the food. In other words, the rat un-learns what it originally learned, and then it learns the new conditions.
One month after withdrawal, alcohol-treated rats showed marked deficits on both the object recognition and un-learning tests. When they were placed in the cage with the objects that should be familiar, they had no recognition. They behaved exactly the way they did when they saw the objects the first time.
On the T test, the rats had what we call perseverative errors. They didn't un-learn where the food was. They kept running down to that one side because they assumed the other side was blocked. They didn't seem to be capable of unlearning what they learned during the alcohol conditioning. And they made twice as many errors as the rats that weren't treated with alcohol.
An extraordinary finding is that animals given nimodipine two weeks prior to withdrawal or as a single dose experience a complete reversal of the memory loss associated with alcohol withdrawal. This means that medication may play a role in alleviating the memory and learning deficits caused by alcoholism.
Alcohol Impairs Learning
When we think of memory, we tend to think of recalling events and experiences from the past. The memory impairment caused by alcohol is not limited to the past, but also extends to prospective memory, or new learning. Specifically, alcohol impairs the ability to learn complex, novel information. The more complex the information, the harder it is to learn, even after the alcoholic stops drinking.
Research shows that alcohol impairs contextual learning. In a recent study, researchers trained a rat to be afraid of a tone by putting it in a shuttle box, ringing a tone and then giving it a foot shock. After a very short period of time, the animal comes to fear both the tone and the box and modifies its behavior accordingly. The rat learns to be afraid of not just the proximate signal, which is the tone, but also the environment.
When the rats are pretreated with alcohol, they learn to be afraid of the tone, but they don't learn to be afraid of the environment. Interestingly, binge drinkers behave like these rats. They fail to learn associations in aversive conditioning tests and they have much more limited learning. As a result, they are not able to avoid situations that are going to be dangerous or threatening to them.
Alcohol also impacts what is called state-dependent learning. Researchers have discovered that if an alcoholic learns something while in a drugged state, they are much less likely to remember it when they are sober. But if they are tested when they are high again, their performance matches what it was when they were trained. In other words, memory that occurs while under the influence translates very poorly when sober. There is little or no transfer of learning from a drugged state to a non-drugged state.
What that means is if something happens while drunk or high, the alcoholic is not necessarily going to remember it when they are sober. The person who drives their car into a tree may not remember how that happened. And it may not be what we call a blackout; it's simply that learning is so impaired that the alcoholic doesn't remember. They may walk into walls, stumble and fall, or get into fights, but their ability to recall the circumstances around those events is impaired because the memory does not carry over to when they're sober.
12-Step Recovery Supports Memory & Learning
The 12-Step process evolved in response to what appeared to be helping other alcoholics. There's tremendous experiential wisdom about how this process works. But how does 12-Step recovery help memory and learning?
Part of the 12-Step process involves the alcoholic retelling the story of what happened to them. One of the reasons that sharing is so important is that alcoholics forget. Alcoholics have specific deficits in avoidance memory. Even when they recover, they have difficulty avoiding situations that are painful or have negative consequences.
An alcoholic may go to a 12-Step meeting and question how many times they need to hear about someone relapsing and having terrible things happen to them. People who aren't recovering alcoholics might not need to hear those stories very often. But recovering alcoholics need to hear them all the time because their ability to internalize the memory has been impaired by the drug.
A common saying in Alcoholics Anonymous is "one day at a time." Most of us are concerned with what we are going to do the next month or year, even the next decade. Are we going to get that promotion? Will we get engaged to a boyfriend or girlfriend?
The focus on one day at a time is a response to the deficits in prospective and working memory that alcoholics experience even after they're sober. These deficits in both short- and long-term memory interfere with logical planning and executive function, so that alcoholics struggle to remember what they're supposed to do. They have trouble planning, and even if they plan things they don't remember what it was they planned or why they wanted to do it. Approaching life one day at a time helps alcoholics function in spite of these impairments.
The whole support system of AA and related programs is organized around the Steps. Why are these Steps important? If alcoholics can't plan, it helps to have a system that continuously reinforces what they're supposed to do next. If there is a deficit in prospective memory, the alcoholic has a program that says first do this, and then do that. And each one of these steps is logically tied to how the alcoholic will get better, so they don't have to remember. Twelve-Step recovery offers regular reminders about what to do next.
Among the many negative consequences of alcohol consumption and alcohol withdrawal are memory and learning problems. Twelve-Step recovery can help compensate for these deficits by reminding alcoholics what they have lost to the disease and the steps they need to take on a daily basis to hold onto their sobriety.
David Sack, M.D., is board certified in psychiatry, addiction psychiatry and addiction medicine. Dr. Sack is CEO of Elements Behavioral Health, a network of addiction and mental health treatment programs that include Promises Treatment Centers and The Ranch. You can follow Dr. Sack on Twitter http://www.twitter.com/drdavidsack.