This piece was written by one of our contributors; graduate of an MSc in Health Psychology – Joe O’Brien.
Waking up on a Sunday morning with a patchy memory, a headache and “the fear” is a relatively common experience for many people these days. In the Global Drugs Study 2018[1], 98.9% of respondents had consumed alcohol, the highest consumed drug by a significant portion. Most of us associate a “hangover” with being a short-term issue, something we get over relatively quickly after that initial day or two, and scientists are still trying to find a cure (spoiler, there is none!). However, some of the psychological research may contradict the idea that the impact of alcohol is only during the hangover period.
A hangover is defined as the period after the consumption of alcohol, when our blood alcohol concentration (BAC) approaches or reaches zero yet we still has adverse affects. It’s severity is partially gauged on the difference between peak BAC and zero BAC[2]. If you asked any of your friends how long a hangover lasts, most would say a day or two, right? Would you believe it if you were told that the impact of alcohol lasted 2 weeks? Maybe not. What about 4 weeks? Well, if we look at the process from a psychological perspective, you might get quite a surprise.
Alcohol, Serotonin and Neurogenesis
The research on alcohol-dependent individuals gives us some insight into the brain changes that occur from drinking. They’ve found significant decreases in serotonin (known as the happiness chemical) during the 14 days after alcohol consumption, not just in that hangover period [3]. This decrease in serotonin may be one of the explanatory factors that contributes to the feeling of low mood not just in the immediacy after drinking, but for a considerable time afterwards. In fact, in this study, serotonin levels did not return to normal levels even after 14 days, compared to controls.
Of course, we are not all alcohol dependent and these results are likely not how a non-alcohol dependent individual would experience these changes, however the acute consumption of alcohol also stimulates serotonin (and other important chemicals) in healthy individuals and levels drop in withdrawal. This happens in a dose dependent fashion, meaning the more often we drink, and the more alcohol consumed, the greater the impact on the outcomes on brain atrophy [4].
It’s important to note that serotonin is not the only chemical at play, but just one which may be a contributor to our mood. Low serotonin levels are common in individuals suffering with depression and anxiety [5], meaning that alcohol consumption can be a significant contributor in the reduction of serotonin in the brain, not just during the initial hangover period but for longer.
So if a hangover is the period after alcohol where we may have adverse effects, how long is our hangover lasting?
In fact, alcohol can impact a process in the brain called “neurogenesis” which is the production of new brain cells. This process can take 4 weeks to produce new cells which replaces old cells in the brain [6]. This process can have an impact on the hippocampus, which regulates emotions and impacts learning and memory, but the true behavioural and emotional impact of these changes is to be debated. Anecdotally, it often takes people a lot longer than a day or two to feel back to “normal” depending on how heavy the drinking session was! If we consider hangover symptoms commonly include low mood, anxiety symptoms and a cloudy head, then you can ask yourself how long a hangover really is? Maybe it’s a lot longer than a day or two, I’m sure some people haven’t felt right for weeks. Alcohol has an impact on the processes in your brain for a lot longer than you might expect.
Trying to understand “the fear” is another complex process but starts with understanding the brain response in that phase after acute or binge drinking helps make sense of it.
The spike in positive neurochemicals such as serotonin, GABA, dopamine etc. leaves us feeling good while we’re intoxicated, however when we withdraw from alcohol and in that hangover period, the levels of these chemicals drop and can leave us with exacerbated symptoms of depression and anxiety. It might be worth telling yourself in that state that these feelings are exactly that – they are only feelings. The severity of those feelings will reside, and this is a physiological response from your brain. It is not reflective of your true state.
As well as the change in brain chemistry, alcohol impacts the quality of sleep, and specifically blocks REM sleep [7], which is an important part of emotional regulation and mental health[8], leaving you more sensitive to emotional stimulus.
Long Term Consumption
One of the most interesting research papers I’ve read in quite a long time was a 30-year longitudinal study done in the UK, which measured more than 500 people’s drinking patterns over that period. What they found was quite remarkable if you compare it to how most people in western culture drink. They found the only level of drinking that was as safe as not drinking at all was 1-7 units per week. They found that there were no differences in brain structure (atrophy) between that group and the abstinent group, but anything above 7 units they found a dose-dependent correlation to hippocampal damage, as well as white matter and some cognitive functioning tests. This means that the more someone drank (once over 7 units) the stronger the association with brain damage. To put this dose into context, that is 3 pints of larger or a half bottle of wine per week!
Of course, people will argue that there are social benefits to drinking and at the minute, there are no studies to weigh the mental health benefits of drinking versus the drawbacks, so that’s an entirely subjective conversation for another day. However, it’s also important to remember you can socialise without alcohol sometimes too and it’s not the key component of having a social life.
Conclusion
The alcohol research is vast, and a short blog is not enough to delve deeply into this topic comprehensively. What it’s important to understand is that based on some of this evidence, alcohol can impact the brain for a lot longer than just the hangover period. Maybe you’re not feeling great a week after a heavy night of drinking. It can be hard to attribute that to the previous week, but it seems evident that the impact of alcohol consumption, especially over time, can have quite a role to play in our brain chemistry and structure, to the point where it exacerbates symptoms of depression and anxiety.
To conclude, alcohol may well give you that short term 24 hours hangover feeling, but the evidence suggests that the impact on your brain lasts a lot longer. In fact, alcohol seems to make symptoms of anxiety and depression worse in the withdrawal period, which may be explained by the significant impact alcohol has on important neurochemicals.
Judging from the first study of its kind, the only “safe” level of alcohol consumption when it comes to brain health, seems to be less than seven units per week. Any more than that has a dose dependent response to white matter volume in the brain as well as hippocampal damage, and from our knowledge of neuropsychology, we know that the hippocampus is vital for emotional regulation, amongst many other key functions.
If you’re not sure if alcohol is an issue for you, check out some of the signs you might be having difficulty with your relationship with alcohol. If you identify with these symptoms, seek support from your GP or a mental health professional such as a chartered psychologist, psychiatrist or accredited psychotherapist.
How to tell if alcohol is becoming an issue:
- Extreme mood swings or irritability
- Inability to stop or moderate drinking
- Drinking alone
- Craving alcohol
- Continuing drinking despite it causing relationship issues or issues with mental or physical health
- Unable to abstain of your own free will
- Prioritising drinking over things like work/friends/family/finance
References:
(1) Winstock A, Barrett M, Maier L, Ferris J. Global drugs survey. 2018.
(2) Penning R, van Nuland M, A. L. Fliervoet L, Olivier B, C. Verster J. The Pathology of Alcohol Hangover [Internet]. 2010 [cited 2019 May 10]. Available from: https://www.ingentaconnect.com/content/ben/cdar/2010/00000003/00000002/art00002
(3) Patkar AA, Gopalakrishnan R, Naik PC, Murray HW, Vergare MJ, Marsden CA. Change In Plasma Noradrenaline and Serotonin Levels and Craving During Alcohol Withdrawal. 2003 May 1;38(3):224–31.
(4) Topiwala A, Allan CL, Valkanova V, Zsoldos E, Filippini N, Sexton C, et al. Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ. 2017 Jun 6;357:j2353.
(5) Baldwin D, Rudge S. The role of serotonin in depression and anxiety. International Clinical Psychopharmacology. 1995;9(Suppl 4):41–5.
(6) Alcohol, Neural Stem Cells, and Adult Neurogenesis [Internet]. [cited 2019 Apr 23]. Available from: https://pubs.niaaa.nih.gov/publications/arh27-2/197-204.htm
(7) Angarita GA, Emadi N, Hodges S, Morgan PT. Sleep abnormalities associated with alcohol, cannabis, cocaine, and opiate use: a comprehensive review. Addiction Science & Clinical Practice. 2016 Apr 26;11(1):9.[8] Vandekerckhove M, Cluydts R. The emotional brain and sleep: An intimate relationship. Sleep Medicine Reviews. 2010 Aug;14(4):219–26.
