Ask An Adult: Why Do I Blackout When I Drink?

We’ve all done it. You wake up in bed the morning after having a big night out and – apart from that horrendous headache – think you just about got away with it. You obviously managed to get yourself home without losing your phone, keys and (fingers crossed!) dignity, even if you can’t quite remember how. Then your phone begins to vibrate.

First there’s a picture on Facebook of you grinding up against some random bloke wearing a deep-V T-shirt with a crazed, hungry look on your face. There’s a corresponding new number in your phone under the name ‘Peteshdvxx’. Not ideal. Then you see that someone’s sent you a WhatsAppmessage asking if you got home OK because you kind of ‘ran off’. Ah. Then the killer arrives – a text from your best mate saying, ‘Are you OK babe? You were pretty upset towards the end of the night xxx.’ Suddenly, it dawns on you: not only have you probably got off with deep-V Peteshdvxx (whoever he is), but you also ran off into the middle of the night alone after crying in public. And there’s photo evidence of the whole thing. Which is lucky in a way, because you can’t remember a thing.

Blackouts can be pretty awful, and if you drink a fair amount regularly, chances are you've had one at least once. But what causes them? And why can you never predict when they're going to happen (as anyone who’s gone for one glass of wine after work on a Friday night and woken up fully-clothed on their bed the next day will attest to)?

‘Alcohol can affect your balance, your motor-co-ordination, decision making and a litany of other functions,’ Dr Sophie Wilkinson of King’s College explains to The Debrief. ‘But it also produces noticeable memory impairment after just a couple of drinks. As your blood alcohol concentration increases, so does the magnitude of these memory impairments. Under certain circumstances, alcohol can disrupt or completely block your ability to form new memories of events that happen whilst you’re drunk – that’s basically what happens when you blackout. I actually know a guy who’s so used to this memory impairment when he drinks that he actually actively writes down anything funny that happens to him over the course of the evening, so he can be sure he’ll remember it the next day.’

That’s incredibly forward-thinking for a drunk person. But despite the fact that most people report the same loss of memory when they blackout, Dr Sophie says there are actually two different variations – with differing degrees of severity. ‘Firstly there is an “en bloc” blackout, which involves quite a long period of memory disruption, so you might not be able to remember anything whatsoever from your entire evening. These big blackouts only tend to happen when you’re taking substances, like illegal drugs or prescribed medication, so the alcohol in your blood is interacting with something else in your blood and your body is dealing with a kind of “double whammy” of substances to break down, which completely interrupts your short-term memory,’ Dr Sophie explains. ‘Slightly less severe is a partial blackout called a fragmentary blackout, which happens when the alcohol concentration in your blood has reached a certain point during the night and from that point forward you can’t form any new memories. So you might remember that last glass of wine you necked, but nothing after that point. Both are caused by a neurophysiological and chemical disruption in the part of your brain integral to memory formation and it’s like anterograde amnesia – when the brain stops being able to form new memories after a precipitating event.’ Namely getting off your tits.

Is the evening then lost forever, or is there a way of jogging your memory? I find being shamed by my friends usually helps. ‘There is anecdotal evidence of something called state-dependent memory,’ explains Dr Sophie. ‘An example often spoken about is that of an alcoholic who used to write loads of notes whilst drunk and hide them around the house. When he woke up sober, he couldn’t remember where he hid his notes, but once he’d had a couple of drinks and was drunk again he’d suddenly remember. There’s no hard evidence, but certainly there’s lots of anecdotal evidence that this type of state-dependent memory could occur when someone shows you a picture or jogs your memory of the evening, it will mimic the state you were in the night before and you might be able to recollect what went on during your blackout. Likewise, you might be able to remember more if you start drinking again. Although, I obviously wouldn’t recommend you start drinking again next time you have a blackout just so you can remember what you got up to!’

Annoyingly, there's something in that old adage that ‘men can hold their booze better than women’. In an unfairly cruel twist of fate, blackouts seem to affect women more than they do men. ‘It’s all to do with body fat,’ Dr Sophie explains. ‘Women tend to have a higher proportion of body fat (around 10%) compared to men and generally weigh less. This means that women have more fat cells and proportionally less body water content. Alcohol is less readily taken up by fatty tissues (which women have more off), so it stays in the blood stream longer and gives you a higher blood-alcohol concentration. Even if you took a man and woman who were the same size, height and weight, the woman would have proportionally more body fat than the man, so her body would find it more difficult to metabolise the alcohol and she’d be more likely to blackout. Sorry.’ But if it’s all about body fat, does that mean loosing weight could decrease your chance of getting a blackout? Would be another reason to start the 5:2, right? ‘Unfortunately not,’ Dr Sophie explains. ‘Thinner women might still have higher levels of subterraneous fat and will be lighter with less body water to dilute the alcohol, so actually they’re probably more at risk of blacking out.’ Well, there goes that theory.

All of this really does sound less than ideal. Is there anything we can do to avoid this (beyond never drinking again)? ‘There are definitely some risk factors,’ says Dr Sophie. ‘Being female is unfortunately one of them, but gulping down drinks really quickly will also increase your chance of blacking out. If you’ve got food lining your stomach, then the alcohol is not going to pass through as quickly and through your small intestine, so if you’ve not eaten anything then it’s just a faster rate of alcohol breakdown and a quicker rise in blood alcohol concentration. So, in other words, if you haven’t eaten, then your chances of crying, blacking out and then being sick are increased. Not a great look. Also, if you’ve had blackouts before, then, I’m sorry, but your chances of having them again are increased. The good news is that there isn’t necessarily any long term consequences of blackouts other than the problems already associated with binge drinking, and it’s not necessarily harmful unless it’s indicative of generally harmful drinking behaviour. Still, there’s no real secret, other than lining your stomach and drinking less, and more slowly.’

Let’s see if we can remember that one…

Follow Sophie on Twitter @sophiecullinane

This article originally appeared on The Debrief.