Brain Damage from Alcohol and Drugs: Are the Effects Reversible?

Terms such as “alcoholic,” “substance abuse,” and “brain damage” are generally terms we avoid using in the articles we publish at American Addiction Centers (AAC). Words and phrases like these are stigmatizing statements, which can create a negative bias, perpetuate the view that addiction is a moral failing—and not a treatable medical disease that individuals can and do recover from—and adversely impact treatment retention.

Can Drugs Damage the Brain?

People can experience a wide range of neurological changes due to substance use, but many of these are a direct result of intoxication and they end after the substance clears the body. Chronic or heavy use of some substances, however, are associated with certain neurological issues that can be detrimental and long-lasting, but these aren’t usually a result of cell death causing permanent neurological injury. In fact, many brain changes or neurological complications that result from substance use can improve or even be reversed when drug and alcohol use stops.

Can Alcohol Damage the Brain?

Alcohol interferes with the brain’s communication pathways and can affect the way the brain looks and works. Alcohol affects the areas of the brain that control balance, memory, speech, and judgement. It makes it harder for these areas to function properly, which puts individuals at a greater risk of injury and other negative outcomes. Alcohol misuse can lead to alcohol-induced blackouts, alcohol overdose, and alcohol use disorder.² 

While the extent of alcohol-related damage to the brain depends on different factors, including how much, how often, and for how long alcohol was consumed, brain changes and complications from alcohol—similar to the changes induced by other substances—can improve and potentially be reversed with abstinence.

What is Brain Injury from Drug Use?

Brain injury resulting from drug or alcohol use can range from minor damage to brain cells to severe physical damage such as in the case of brain hypoxia due to overdose. Some of these consequences can be more serious and/or persistent, such as in the case of traumatic brain injury (TBI), stroke, and Wernicke–Korsakoff syndrome.^1,3,4 Others can include potentially reversible changes such as mild brain atrophy (brain shrinkage) and changes to white matter.^5,6

Brain injury or other neurological complications can be a direct or indirect result of substance use. Brain hypoxia, a lack of sufficient oxygen to the brain, can result from an overdose of opioids, for example, which can significantly decrease the body’s respiratory drive. However, brain injuries can also occur due to poor health and nutrition, accidents, or increased risk-taking behaviors people engage in while they’re intoxicated or because they have a substance use disorder.^4,7

Certain substances may have neurotoxic effects at high doses or with chronic exposure. These are substances that may cause damage or injury to brain cells. Taking these substances, especially over longer periods of time or at certain times in the human aging process, could increase your risk of suffering from substance-related brain changes or neurological issues. For example, high-dose or chronic amphetamine use may accelerate and enhance a person’s age-related decline in dopaminergic function.¹

Do Certain Drugs Damage Brain Cells?

Different drugs can have neurotoxic and destructive effects on brain cells. Substances that are associated with neurological damage include—but are not limited to—alcohol, heroin, amphetamines, marijuana, opioids, inhalants, and cocaine.^1,3,6

Drugs can damage brain cells through several mechanisms. Psychostimulants (e.g., amphetamines) and alcohol disrupt the integrity of the blood-brain barrier (BBB), which can change the functioning of your brain cells due to increased permeability. Permeability refers to the extent to which your brain is protected from toxins that could enter the brain from your blood supply. Increased permeability means that toxins can more easily cross the BBB.⁸

Other substances, including alcohol and inhalants, can cause injury to brain cells due to the way they damage the protective sheaths, known as myelin, that surround nerve fibers. This can cause damage, like that which occurs in neurological diseases like multiple sclerosis (MS). This type of damage can affect your thinking, movement, vision, and hearing. The neurological symptoms people experience in this case can range from mild to severe.^9,10

Effects of Addiction on the Brain

Sustained misuse of certain substances can cause potential long-term neurological effects or changes to brain function. These include traumatic brain injuries, headaches, a range of persistent neurological and cognitive complications, and brain changes, such as the loss of gray matter, reduced hippocampal volume, and enlarged cerebral ventricles—the network that connects areas of your brain—may occur as a result of chronic substance misuse.¹¹ Potential consequences and brain changes vary by substance and can include the development of some of the problems below.

Stimulants and Anhedonia

Anhedonia is the inability to experience pleasure. It is often a symptom of substance use disorder (e.g., lack of interest in activities you once enjoyed and experienced as rewarding), as well as intoxication and withdrawal. Research has shown that all types of chronic stimulant use (such as cocaine or amphetamine) are associated with anhedonia, and some researchers theorize that it can be long-lasting for chronic/heavy stimulant users due to damage or permanent changes in the dopaminergic reward system.¹²

Hallucinogen Persisting Perception Disorder

Hallucinogen persisting perception disorder (HPPD) can be a rare, long-lasting neurological consequence of hallucinogen misuse. It typically occurs with LSD but may also occur following use of other hallucinogens like MDMA (ecstasy), psilocybin, and mescaline.¹³

HPPD is characterized by flashbacks and chronic or recurrent perceptual symptoms that can make it feel like you are re-experiencing the feelings or sensations you experienced when you used the drug. The key symptom tends to be visual hallucinations (seeing things that aren’t there), which may cause significant distress and affect your ability to function.¹⁴

Wernicke-Korsakoff Syndrome and Alcoholic Dementia

Alcohol misuse can lead to several different neurological complications, with an increased risk for chronic, heavy alcohol users.

One serious neurological condition is known as Wernicke–Korsakoff Syndrome (WKS). This is a condition that can occur due to vitamin B1 (thiamine) deficiency, which commonly occurs in people who chronically misuse alcohol. Two syndromes make up WKS. One is acute (short-term) Wernicke encephalopathy, which causes symptoms like confusion, paralysis of nerves that control eye movements, and muscle coordination problems. When caught early, Wernicke encephalopathy is reversible, however, around 80-90% of people who develop encephalopathy will progress to Korsakoff’s psychosis, which can be long-lasting and cause chronic, irreversible learning and memory problems.⁴ Severe cases of WKS carry a mortality rate of 10% to 15%.¹⁵

High-level alcohol consumption is linked to an increase in dementia risk, however, the link between alcohol and dementia is an area still undergoing research.

Alcohol intoxication can lead to TBI, with studies estimating between 30% and 50% of patients treated for TBI were also intoxicated at the time of injury.  TBIs can be mild to severe, and they occur after trauma or injury to the brain that causes swelling, increased intracranial pressure, and reduced blood flow, resulting in different neurological symptoms and cognitive deficits including memory loss. Alcohol use in people diagnosed with a TBI can significantly elevate their risk of experiencing a future TBI. Repeated TBIs produce more severe long-term damage and an increased likelihood of permanent disability.¹⁷

Hypoxic Brain Damage from Overdose

Overdoses of certain substances can lead to potentially fatal neurological complications and injuries, including hypoxia, the shortage of oxygen delivery to the brain, and anoxia, meaning the total loss of oxygen that is usually due to hypoxia.^18,19

Hypoxic brain injury can occur due to respiratory depression, a serious consequence of opioid overdose.²⁰ In addition to being a particular risk with opioids (such as heroin, OxyContin or fentanyl), use of benzodiazepines, alcohol, or other sedatives can also lead to respiratory depression. Poly-substance use, which often involves combining substances that have depressant effects, such as opioids, sedatives, or alcohol, can have unpredictable and dangerous outcomes.²⁰

Overdose survivors may develop a hypoxic brain injury that leads to long-lasting or even permanent damage such as  short-term memory loss, stroke, mental disorientation, loss of body movement, changes in gait, incontinence, temporary leg paralysis, reduced motor skills, slowed reaction time, seizures, nerve injury, and memory impairment.²¹

Neurological Damage from Withdrawal

Neurological complications may result from withdrawal of certain substances. Medically supervised detox may help to reduce the likelihood or severity of many of these risks. You will receive constant monitoring and supervision as well as medication to address any symptoms or complications that may arise as a result of withdrawal.²²

Withdrawal from substances like alcohol and benzodiazepines may also present a risk of withdrawal seizures.^22,23 Seizures can be dangerous because you can suffer from falls or injuries or develop a potentially lethal condition known as status epilepticus, which is when you have a seizure that lasts more than 5 minutes or when seizures occur too often in too short of a time span.²⁴

Can Brain Damage Be Reversed?

Certain brain changes can be persistent or permanent, but this can vary widely depending on the type of injury and the substance of misuse. Many substance-related neurological complications or consequences may also be reversible.

WKS, for instance, may present with more chronic and debilitating effects, but when caught early and with proper treatment, WKS might be reversible in certain cases. Research has shown that even people who have suffered from a stroke can make some degree of recovery. There is also some evidence that indicates that brain shrinkage and reduced white matter volume associated with alcohol misuse may be reversible.^25-28

The National Institute on Drug Abuse (NIDA) explains that some of the neurological damage to the dopaminergic system appear, at least partly, to be reversible, with many neurological markers for nerve damage returning to normal after several months of abstinence.²⁹ The National Institute on Alcohol Abuse and Alcoholism (NIAAA) points out that although it can take time, most people suffering from alcohol addiction will experience at least some improvement in brain structure and functioning with abstinence.⁴

The brain is a complex organ that can adapt to many stressors and circumstances, a concept known as neuroplasticity. People are resilient creatures, and the body and brain were designed to be able to heal themselves. Certain forms of treatment can augment this process and enhance neurological recovery. According to one report, more than 85% of TBIs are considered to be mild, and most people recover from these injuries with medical treatment.³⁰ For those with a substance use disorder, seeking help from addiction and stopping your use of substances may help prevent or heal some of the neurological consequences of substance use and help you take back, not only your physical health, but also your mental health and overall wellbeing.

If you or a loved one struggle with substance misuse or addiction, it’s never too late to seek help, regain your life, and improve your physical and mental health. American Addiction Centers can help. Call to speak to one of our compassionate admissions navigators, who can listen to your story, explain your options, and help you begin your journey to recovery today.