Addiction Alcohol Use How Alcohol Causes Brain Shrinkage By Buddy T Buddy T Facebook Twitter Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism. Learn about our editorial process Updated on May 22, 2022 Medically reviewed Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Huma Sheikh, MD Medically reviewed by Huma Sheikh, MD Facebook LinkedIn Twitter Huma Sheikh, MD, is a board-certified neurologist, specializing in migraine and stroke, and affiliated with Mount Sinai of New York. Learn about our Medical Review Board Print Manuel Breva Colmeiro / Getty Images Table of Contents View All Table of Contents Brain Shrinkage From Alcohol Other Effects of Alcohol Is Brain Shrinkage Permanent? Impact of Brain Shrinkage Multiple research studies have found that the brains of people with severe alcohol use disorder are smaller and lighter than the brains of those who do not have this condition. This alcohol-linked brain shrinkage affects the networks that regions of the brain use to communicate with other regions. The parts of the brain that allow neurons to communicate with neighboring neurons are also affected. Some Damage Is Reversible Although chronic alcohol misuse causes significant brain damage, abstinence can reverse some (but not all) damage. With appropriate interventions, people with alcohol use disorder can attain long-term sobriety despite deficits in decision-making related to brain shrinkage. How Alcohol Causes Brain Shrinkage The gray matter in the cerebral cortex controls most of the brain's complex mental functions. The cortex is filled with neurons that connect by fibers to different regions of the brain and to other neurons inside the brain and spinal cord. The nerve fibers are the white matter of the brain—the "hard-wiring." These nerve fibers have numerous shorter fibers called dendrites that branch out like the roots of a tree to allow the neurons to "talk" with other neurons. A neuron can communicate with as few as five or as many as 10,000 other neurons at a time. These two parts of the brain—the white matter and the dendrites—are most vulnerable to the shrinkage that alcohol misuse can cause. Brain shrinkage is not the only way alcohol misuse can damage the brain. Alcohol can also cause chemical changes that affect the function of neurotransmitters (chemical messengers that carry signals between the brain to the rest of the body). How Alcohol Affects the Brain Chronic alcohol misuse creates complex, toxic metabolic and nutritional interactions that can cause mental deficits. Some of these are still not understood completely. Acetaldehyde, a chemical that is produced when alcohol is metabolized, could cause toxic effects. Malnutrition, especially thiamine deficiency, could play a role. Cirrhosis of the liver can also cause brain damage. Head injury and sleep apnea can contribute to brain damage. Alcohol, thiamine deficiency, and cirrhosis are linked. Some researchers believe they contribute in a complex manner to brain damage. Is Brain Shrinkage Permanent? Some of the brain damage caused by alcohol can be reversed if a person stops drinking and maintains a period of abstinence. But some of it is permanent and cannot be undone. The most significant permanent damage caused by alcohol is nerve cell loss. Some nerve cells cannot be replaced once they are lost, including those in the frontal cortex, cerebellum, and other regions deep inside the brain. However, abstinence can help reverse the shrinkage of dendrites. Studies show they will begin to grow again after weeks or months of abstinence. Once this happens, brain function may improve. Some of the brain damage caused by cirrhosis of the liver can begin to reverse with treatment. Brain damage due to thiamine deficiency in people who misuse alcohol can easily be treated with thiamine supplements, but repeated deficiencies can cause permanent damage. MRI Images Show How Alcohol Can Damage the Brain Impact of Brain Shrinkage Caused by Alcohol Use One reason that people with alcohol use disorder are so prone to relapse is the damage alcohol causes to the brain's reward system and decision-making abilities. The result is that the person is more motivated by immediate rewards than delayed ones. Addictive substances such as alcohol provide immediate intoxicating rewards. Chronic alcohol misuse chemically changes the brain's reward system to the point that the drinker's pursuit of rewards becomes pathological. Long-term, heavy alcohol consumption affects the brain's frontal lobe functions, which include inhibition, decision-making, problem-solving, and judgment. This kind of brain damage makes it difficult to maintain long-term sobriety. 10 Tips for Cutting Back on Drinking However, people with alcohol use disorder can overcome these challenges with abstinence, which helps reverse the damages. They then can achieve long-term, multi-year sobriety when motivated to do so. If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area. For more mental health resources, see our National Helpline Database. 9 Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Mon A, Durazzo TC, Abe C, et al. Structural brain differences in alcohol-dependent individuals with and without comorbid substance dependence. Drug Alcohol Depend. 2014;144:170-177. doi:10.1016/j.drugalcdep.2014.09.010 Yalcin EB, McLean T, Tong M, de la Monte SM. Progressive white matter atrophy with altered lipid profiles is partially reversed by short-term abstinence in an experimental model of alcohol-related neurodegeneration. Alcohol. 2017;65:51-62. doi:10.1016/j.alcohol.2017.05.008 Carter J, Sharon E, Stern TA. The management of alcohol use disorders: The impact of pharmacologic, affective, behavioral, and cognitive approaches. 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Brain. 2006;130(1):36-47. doi:10.1093/brain/awl303 Harper C, Matsumoto I, Pfefferbaum A, et al. The pathophysiology of 'brain shrinkage' in alcoholics — Structural and molecular changes and clinical implications. Alcohol Clin Exp Res. 2005;29(6):1106-1115. doi:10.1097/01.ALC.0000171490.09017.A9 By Buddy T Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Get Treatment for Addiction Advertiser Disclosure × The offers that appear in this table are from partnerships from which Verywell Mind receives compensation.