Understanding Why We Black Out after Drinking

It’s quite common to be on a night out and not remember everything that happens. Maybe there are some small gaps in our memory, or we have the order of events slightly mixed up. This is potentially quite a frequent experience and is thought to be linked to the disorientation we can feel whilst drinking. What is perhaps less normal, though, is having large missing chunks. This resembles memory loss more than mere disorientation. This is called a blackout. We may hear the phrase ‘blackout drunk’ but what does this mean from a clinical perspective? What happens when we black out, and what causes it? Are blackouts dangerous? Could frequent blackouts represent a sliding away from heavy drinking towards potential alcohol addiction?

What are blackouts?

Our memories often get hazy after drinking. One researcher, in a 2003 paper, focuses on the role that alcohol plays in memory loss. Generally speaking, ‘as the amount of alcohol consumed increases, so does the magnitude of the memory impairments.’

Blackouts can range from small, partial gaps to complete blackouts, which are defined as ‘periods of memory loss for events that transpired while a person was drinking.’ Blackouts sometimes cause us to forget short periods of time, whilst others can lead to us omitting entire chunks – even hours. We can see that blackouts could become a problem for drinkers. Forgetting a conversation, for example, is one thing – but forgetting entire events – such as intercourse – can carry a wide range of risks for the drinker.

According to recent research, these kinds of blackouts happen for about 50% of drinkers. Whilst on the surface this may seem like a minor issue, it has been found that blackouts can be linked to a broad list of consequences, ‘including injury and death.’  Due to this, educating ourselves to understand how and why blackouts happen is a very important way of managing alcohol-related injury and risk.

Why do they happen?

For some time, researchers indicated that blackout drinking was only impacted by the amount that someone drank. For example, the more alcohol someone drank, the more likely they were to experience a blackout. But this isn’t always the case. Blackouts can, indeed, sometimes be linked with the quantity of alcohol consumed. But it is thought to be more closely related to how fast it enters the bloodstream instead of solely how much someone drinks.

The physiology

There are several physiological mechanisms that can be linked with blackouts occurring. This ranges from the way our bodies process alcohol to the way that it interacts with certain areas of our central nervous system after it enters the brain.

Metabolism

If blackouts can be linked to how fast alcohol enters the bloodstream, then it could on some level be predicted by metabolism. Just like other kinds of food and drink, alcohol is metabolised by the body after we consume it. It enters our stomachs and is absorbed into our stomach lining. From there, it enters our bloodstream and is carried to the brain. This process is thought to take on average around 10 to 15 minutes. But some people have a naturally faster or slower metabolism, meaning that this process could take slightly more or less time to occur.

People with a slower metabolism might therefore drink more without feeling the effects. They may then have a larger quantity of alcohol entering their bloodstream at once, which can quickly increase their blood alcohol level and potentially increase the likelihood of a blackout.

The hippocampus

Blackouts are thought to occur when alcohol interacts with specific areas of the brain. One researcher explains how ‘alcohol-induced memory impairments include disruption of activity in the hippocampus.’ The hippocampus is a very complex brain structure that governs our short-term memory. By disrupting the functioning of the hippocampus, alcohol can act to inhibit our ability to make new memories. This alteration in short-term memory making can lead to blanks in our memories. These, effectively, are blackout periods.

The psychology

Blackouts happen when our memories have not been consolidated correctly. We can explain this by looking at the way our brains act when we have reached a certain blood alcohol level. Another way we can look at blackouts is as a psychological phenomenon. For instance, it can be possible that a blackout can occur as a method of self-protection. For example, if we have experienced negative incidents – for example, an instance of violence – our brains can repress our memories.

In this case it may be argued if the ‘forgetting’ is a true blackout or rather a psychological mechanism or type of dissociative amnesia. But regardless of where the memory-blocking comes from, it can function in the same way as a ‘traditional’ alcohol induced blackout.

The dangers of blackouts

Blacking out effectively means parts of our memories are erased. This can pose several risks, such as being unaware of:

• exposure or involvement in violence
• exposure or involvement in crime
• engagement in unsafe sex
• engagement in non consensual sex
• the occurrence of an injury

When we drink alcohol, we become intoxicated. This can already lead us to be at increased risk of danger, as well as ourselves becoming more unpredictable. If we have blackouts, it can be very difficult to identify if we have experienced (or caused others to experience) unsafe or uncomfortable situations. At best, this can lead to awkwardness and misunderstanding. At worst, it can lead to tangible dangers for us as well as others around us.

The risks of excessive drinking

If blackouts happen when our blood alcohol content hits a certain level, then it is likely to be linked with increased alcohol consumption. Frequent experiences of blackouts could therefore point to a habit of alcohol abuse. If you continue to commonly drink over recommended amounts, then you are likely at increased risk of serious health consequences.

Other than the potential vulnerabilities to experiencing (and perpetrating) violence or uncomfortable situations as mentioned above, heavy drinking can come with further, longer term threats. These can include:

• developing addiction
• experiencing withdrawal symptoms
• cardiovascular difficulties
• persistent headaches
• gastrointestinal issues
• kidney and liver damage
• hypertension
• weight change
• difficulty sleeping
• social withdrawal
• alcohol-induced psychosis
• mood swings
• suicidal thoughts
• aggression
• anxiety
• paranoia

Over time, these effects can start to deplete our quality of life. They can leave us feeling overwhelmed and very alone. These physical and mental effects can also disturb our ability to go about our days as usual. This can lead us towards difficulties engaging with our responsibilities, catalysing social, professional, legal or financial complications in the longer term. This can increase a sense of isolation and feelings of deep despair. By addressing drinking issues early, you can prevent these consequences from occurring.

Get help for alcohol addiction

Alcohol can take over lives. Whether you are looking for advice for yourself or a loved one, there are many resources available. Support for drinking problems comes in all forms – at UKAT, there is an appropriate route to recovery for everybody. Contact us today to seek judgment-free, specialist advice from a member of our admissions team. Make today the day you make a stand and take a step towards an alcohol-free life.