Alcohol and the brain

A healthy brain relies on a delicate balance of chemicals and processes. Alcohol is a depressant, which means it disrupts that balance.

Every time you drink alcohol, it affects your brain. As well as feeling less inhibited and being less able to make clear judgments, you are risking long-term effects for your brain and mental health.

How alcohol affects your brain

The type of alcohol in alcoholic drinks is a chemical called ethanol. Ethanol is a very small molecule, so when you drink it reaches most parts of your body – including your brain.

Small amounts of alcohol can cause initial feelings of relaxation, but what’s actually happening is that alcohol is suppressing activity in parts of the brain associated with inhibition.¹

Even after you’ve stopped drinking, your brain and central nervous system are still affected while they process the alcohol, which can lead to withdrawal symptoms.

Brain chemistry

The way alcohol affects the brain is partly down to its effect on ‘neurotransmitters’ - the chemicals that help to transmit signals from one nerve (or neuron) in the brain to another. The more you drink in a session the higher the chance it will cause feelings of tension and anxiety, because of effects on these brain chemicals.²

Research has found that regular heavy alcohol consumption over a long period is associated with a decline in the number of brain cells (or ‘neurons’), and their quality.³

Regular heavy drinking can cause:

Withdrawal symptoms- as your brain and central nervous system process the alcohol, the brain has had to adjust to regularly dealing with alcohol. If alcohol is suddenly not there, you can suffer from ‘rebound agitation’ where the adjustment causes feelings of intense anxiety and irritability.
Alcohol dependence- where you become psychologically and/ or physically addicted to drinking.

A good way to protect your brain health is to follow the UK Chief Medical Officers’ low risk drinking guidelines. To keep health risks from alcohol to a low level, it’s safest to drink no more than 14 units a week - spread over three or more days with several drink-free days every week, and no bingeing.

Alcohol-related brain damage

Alcohol-related brain damage (ARBD) is damage caused to the brain by regular heavy drinking or binge drinking over several years.⁴ (It’s also sometimes called ‘alcohol-related brain injury’.)

Alcohol-related brain damage can happen for a number of reasons:

Alcohol is toxic. When alcohol molecules reach the brain, they can damage brain cells
Brain cells can be damaged if your body doesn’t have enough water – and alcohol is dehydrating (a ‘diuretic’)
Higher blood pressure caused by alcohol is linked to stroke (where the brain is injured by being starved of oxygen)
Liver damage caused by alcohol (or other causes) can mean the brain is exposed to more toxins which would normally be dealt with by the liver (‘hepatic encephalopathy’)
Fights and falls linked to drinking alcohol can cause brain injury
Heavy drinking tends to be associated with poor diet, which can cause malnutrition and can be harmful for the brain
The brain doesn’t get enough essential vitamins (especially B vitamins, like thiamine) because alcohol interferes with their absorption from your diet

Heavy drinking can lead to malnutrition (due to poor appetite or poor nutrition, or diarrhoea and vomiting) which can make the brain suddenly short of the vital vitamin B1 – also known as thiamine. This, in turn, can cause a specific brain illness called Wernicke-Korsakoff Syndrome, leading to impaired recent memory, difficulty learning new information and poor balance.⁵

Alcohol-related brain injury can also cause alcohol-related dementia. In common with many other health harms caused by alcohol, the likelihood of developing these problems increases the more you drink over time.

Binge drinking and blackouts

Drinking a lot of alcohol in a short space of time (which some people call binge drinking, or heavy session drinking) can be dangerous. It affects your brain function – making you more impulsive, slowing your reaction times and affecting your balance.⁶

You are more likely to vomit, have an accident or become involved in a fight, or even lose consciousness with the risk that breathing stops.⁷

Another possible consequence is ‘blackouts’ - gaps in your memory for events that occurred while you were intoxicated. These gaps happen if you drink enough alcohol to temporarily block the transfer of memories from short-term to long-term storage - known as memory consolidation.⁸

Alcohol and brain development

The developing brain can be harmed by alcohol.

Drinking during pregnancy

Alcohol can cause harm to a developing baby at any point during pregnancy,⁹ and the more that is consumed, the greater the risk.^10,11

When a pregnant woman drinks, alcohol goes through the placenta to the fetus via the bloodstream. This has a number of harmful effects on a developing fetus, including destroying brain cells¹² and damaging developing organs,¹³ and can lead to one of several serious life-long conditions for the child, that are together called Fetal Alcohol Spectrum Disorder (FASD).

Find out more about FASD

Underage drinking

During childhood and teenage years, the brain and body are still developing. Alcohol – even small amounts - can affect memory function, reactions, learning ability and attention span.¹⁴

Evidence also reveals that children who start to drink by age 13 are more likely to go on to have worse grades, to skip school and even to be excluded from school.¹⁵

The risks associated with underage drinking are why England’s Chief Medical Officer recommends an alcohol-free childhood is the healthiest and best option.

Alcohol, the brain and mental health

The more alcohol you drink regularly, the greater the effect it has on your brain function including – potentially – your mental health.¹⁶

Long-term heavy drinking is linked to dementia. Recent research has found that the risk of dementia was increased in people who regularly consumed more than 14 units of alcohol per week.¹⁷ Heavy drinking, or repeated binge drinking, can also cause alcohol-related brain damage – which can lead to alcohol-related dementia.
Alcohol makes stress harder to deal with. On a day-to-day basis, research has shown that alcohol makes stress harder to deal with.^18,19
Alcohol can cause depression or anxiety, or make them worse. Alcohol is a depressant. Drinking heavily and regularly is linked with depression²⁰ and anxiety; and withdrawal from alcohol can temporarily cause or worsen anxiety.²¹
Heavy drinking increases the likelihood of suicidal thoughts. The immediate effects of alcohol, like increased impulsiveness, and the long-term negative effects on physical and mental health mean there is a strong association between heavy drinking and suicidal thoughts or actions.²²

Find out more about the link between alcohol and suicidal thoughts.

Severe withdrawal symptoms are life-threatening – find out more about what they are and how to get help here.

If you're worried about your drinking, our Drinking Check self-assessment below can help you identify if the the amount you drink could be putting your health at risk.

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Support

How to cut down on alcohol at home

If you drink alcohol at home, cutting the amount you have can be a good way to stick to the low risk drinking guidelines and improve your health.

Alcohol support services

If you are concerned that you or someone you care about has a problem with alcohol there is a lot of help available. Here you can find useful links and phone numbers to get the support you need.

References

[1] Liu, Y., Grasman, R. P. P. P., Wiers, R. W., Ridderinkhof, K. R., & van den Wildenberg, W. P. M. (2021). Moderate acute alcohol use impairs intentional inhibition rather than stimulus-driven inhibition. Psychological Research, 85(4), 1449–1461. https://doi.org/10.1007/s00426-020-01353-w

[2] Gimeno, C., Dorado, M. L., Roncero, C., Szerman, N., Vega, P., Balanzá-Martínez, V., & Alvarez, F. J. (2017). Treatment of Comorbid Alcohol Dependence and Anxiety Disorder: Review of the Scientific Evidence and Recommendations for Treatment. Frontiers in Psychiatry, 8, 173. https://doi.org/10.3389/fpsyt.2017.00173

[3] Daviet, R., Aydogan, G., Jagannathan, K., Spilka, N., Koellinger, P. D., Kranzler, H. R., Nave, G., & Wetherill, R. R. (2022). Associations between alcohol consumption and gray and white matter volumes in the UK Biobank. Nature communications, 13(1), 1175. https://doi.org/10.1038/s41467-022-28735-5

[4] Alzheimer’s society website. Alcohol-related brain damage (ARBD): what is it and who gets it? [Accessed 16 November 2022]. Available at: https://www.alzheimers.org.uk/about-dementia/types-dementia/alcohol-related-brain-damage-arbd

[5] Alzheimer’s Society website. Wernicke–Korsakoff syndrome. (Accessed 12 October 2022.) Available at: https://www.alzheimers.org.uk/about-dementia/types-dementia/wernicke-korsakoff-syndrome

[6] NHS website. Alcohol poisoning. (Accessed 10 February 2022) Available at: https://www.nhs.uk/conditions/alcohol-poisoning/#overview

[7] Waszkiewicz, N., Galińska-Skok, B., Nestsiarovich, A., Kułak-Bejda, A., Wilczyńska, K., Simonienko, K., Kwiatkowski, M., &Konarzewska, B. (2018). Neurobiological Effects of Binge Drinking Help in Its Detection and Differential Diagnosis from Alcohol Dependence. Disease Markers, 2018, 5623683. https://doi.org/10.1155/2018/5623683

[8] National institute on Alcohol Abuse and Alcoholism website. Interrupted memories: alcohol-induced blackouts. (Accessed 12 October 2022). Available at: https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/interrupted-memories-alcohol-induced-blackouts

[9] Bailey, B. A., & Sokol, R. J. (2011). Prenatal alcohol exposure and miscarriage, stillbirth, preterm delivery, and sudden infant death syndrome. Alcohol research & health : the journal of the National Institute on Alcohol Abuse and Alcoholism, 34(1), 86–91.

[10] Sundermann, A. C., Zhao, S., Young, C. L., Lam, L., Jones, S. H., Velez Edwards, D. R., & Hartmann, K. E. (2019). Alcohol Use in Pregnancy and Miscarriage: A Systematic Review and Meta-Analysis. Alcoholism, clinical and experimental research, 43(8), 1606–1616. https://doi.org/10.1111/acer.14124

[11] Wilhelm, C. J., & Guizzetti, M. (2016). Fetal Alcohol Spectrum Disorders: An Overview from the Glia Perspective. Frontiers in integrative neuroscience, 9, 65. https://doi.org/10.3389/fnint.2015.00065

[12] Popova, S., Dozet, D., Shield, K., Rehm, J., &Burd, L. (2021). Alcohol’s Impact on the Fetus. Nutrients, 13(10), 3452. https://doi.org/10.3390/nu13103452

[13] Squeglia, L. M. (2020). Alcohol and the developing adolescent brain. World Psychiatry, 19(3), 393–394. https://doi.org/10.1002/wps.20786

[14] Sari, Y. (2017). Commentary: Targeting NMDA receptor and serotonin transporter for the treatment of comorbid alcohol dependence and depression. Alcoholism, Clinical and Experimental Research, 41(2), 275.

[15] Sabia, S., Fayosse, A., Dumurgier, J., Dugravot, A., Akbaraly, T., Britton, A., Kivimäki, M., & Singh-Manoux, A. (2018). Alcohol consumption and risk of dementia: 23 year follow-up of Whitehall II cohort study. BMJ (Clinical research ed.), 362, k2927. https://doi.org/10.1136/bmj.k2927

[16] Becker, H.C. (2017). Influence of stress associated with chronic alcohol exposure on drinking. Neuropharmacology, 122, 115-126.

[17] Windle, M. and Windle, R.C. (2015). A prospective study of stressful events, coping motives for drinking, and alcohol use among middle-aged adults. Journal of Studies on Alcohol and Drugs, 76(3),465-473.

[18] Abrahao, K. P., Salinas, A. G., & Lovinger, D. M. (2017). Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron, 96(6), 1223–1238. https://doi.org/10.1016/j.neuron.2017.10.032

[19] Day, E., & Daly, C. (2021). Clinical management of the alcohol withdrawal syndrome. Addiction.

[20] Edwards, A.C., Ohlsson, H., Sundquist, J., Sundquist, K. and Kendler, K.S. (2020). Alcohol use disorder and risk of suicide in a Swedish population-based cohort. American Journal of Psychiatry

Last Reviewed: 7th March 2023

Next Review due: 7th March 2026

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