Despite being legal, alcohol is one of the most destructive drugs available. The National Institute on Alcohol Abuse and Alcoholism estimates that misuse of alcohol costs the United States more than $220 million per year. In addition to taking its toll on the liver and other body parts, chronic alcohol use can significantly impair everyday memory.
Effect of Alcohol on the Brain
There is a special barrier surrounding the brain to keep dangerous molecules, such as poisons, from entering this sensitive tissue. Alcohol, however, easily crosses this barrier to impact brain cells. Alcohol is called a central nervous system depressant, meaning that it decreases activity in vulnerable brain areas. This is what leads to many of alcohol’s troubling effects, including slowing your heart rate and leading to blackouts.
Alcohol affects two main brain chemicals responsible for sending signals between different areas of the brain. First, alcohol decreases the release of a chemical called glutamate, which typically increases energy levels and brain activity. Alcohol also increases release of GABA, an inhibitory molecule that shuts down certain brain functions. The combination of these effects significantly reduces brain activity.
Short-Term Memory Loss
Approximately 25% of the general population engages in binge-drinking, which is defined as having five or more drinks on one occasion. This number rises to 40% among college-aged individuals. Memory impairment can occur after having just a few drinks. The effects are particularly strong when a person has several drinks in close succession or drinks heavily on an empty stomach.
One of the primary dangers of binge-drinking is that it often leads to alcohol blackouts, which is when a person is unconscious and unaware of events. Blackouts result in loss of memory for a particular time period. Sometimes, this manifests as forgetting key details of an event. In other situations, a person may not remember how they got home or talking to a friend while drunk.
Blackouts aside, chronic alcohol use increases a person’s risk of everyday memory problems. Drinking heavily leads to problems in two key memory processes.
- Retrospective memory. Retrospective memory refers to events that have taken place in the past. This might include remembering facts, recalling the details of an event (for example, your 16th birthday), or remembering what you bought from the store last week. Chronic alcohol use often impairs retrospective memory, leading to lapses in memories of everyday events.
- Prospective memory. Prospective memory refers to the ability to remember to do things in the future. On a practical level, this might include remembering to take medications or attend a meeting or repeating a story because you’ve forgotten you already told it.
Chronic alcoholism often leads to a deficiency in key vitamins and minerals needed by the body to function normally. One of the hallmark vitamin deficiencies is an inability to get enough vitamin B1, or thiamine. This results in a condition known as Korsakoff’s syndrome, also known as Korsakoff’s dementia. Symptoms of Korsakoff’s syndrome include the following:
- Anterograde amnesia. Anterograde amnesia means that a person cannot form new memories. Someone with anterograde amnesia may insist that he or she hasn’t met you despite having interacted with you on several previous occasions.
- Retrograde amnesia. This type of amnesia refers to memory loss of older memories, those created before the onset of Korsakoff’s syndrome.
- Confabulation. People with Korsakoff’s syndrome often make up memories that they then believe to be true. They don’t do this on purpose, but rather they actually cannot distinguish the difference between reality and made-up events.
- Poor content in conversation.
- Lack of insight. Despite having persistent memory deficits, those with Korsakoff’s syndrome lack insight into their impairments.
- Apathy. It is very difficult to motivate someone with Korsakoff’s syndrome to begin a project, take part in an activity, or even get out of bed.
Chronic alcohol use has major effects on the brain, particularly regarding memory. Getting help for alcoholism can halt or reverse these memory problems.