How Do Drugs and Alcohol Affect the Brain?

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Sure, you know that drugs and alcohol can affect how you feel. A little cocaine to pick you up, maybe an opioid to relieve pain; benzo to slow things down. Or how about some alcohol to do it all? Maybe this time you’ll do some combinations. But have you stopped to consider what it is doing to your brain?

How Your Brain Works

Your brain can be compared to an extremely complicated computer. Except:

  • The brain uses billions of cells called neurons instead of circuits on silicon chips.
  • These neurons are organized into circuits and networks with each neuron acting as a switch that controls the flow of information.
  • If a neuron gets enough signals from other neurons on the circuit, it sends off its own signal to the other neurons through a neurotransmitter, also called a chemical messenger.

Sending the Message

  • A neurotransmitter is released by a neuron into the gap between it and the next cell.
  • The neurotransmitter crosses the gap between neurons and binds to the receptors on the next neuron, like a key into a lock.
  • Then, other molecules called transporters “recycle” the neurotransmitters by bringing them back to the neuron that sent them.
  • This shuts down the signal between the neurons.

Alcohol’s Effects on the Brain

Since it’s the easiest to get, legal, and most acceptable to society, let’s start with alcohol. Typically, severe alcohol-related brain damage starts after years of heavy drinking. But negative effects on the brain happen after only a few drinks.

The effect that alcohol has depends on a number of factors including:

  • The amount and frequency of alcohol consumed.
  • The age drinking started and how long they’ve been drinking.
  • The current age of the person, overall health, gender, and genetics.
  • Family history of substance abuse (of any kind).

The Impact of Alcohol on the Brain

In general, alcohol is linked to over 200 diseases, injuries, and conditions. And although it can take years of heavy drinking for diseases like alcohol-related brain damage to appear, negative effects on the brain can show up after only a few drinks.

As you consume alcohol, you begin to feel the depressant effects that it has on your brain. Because the brain is the body’s control center, the impairing effects of alcohol rapidly interfere with the normal function of areas all over the body.

Short-term Symptoms

Short-term symptoms that reveal a reduced brain function include:

  • Difficulty walking
  • Slow reaction time
  • Weakened memory
  • Blurred vision

The short-term effects of alcohol mask the long-term damage alcohol can cause.

How Does Alcohol Cause Long-Term Brain Damage?

Binge drinking and heavy drinking can cause permanent damage to the brain and nervous system. Why? Because alcohol is a toxin. And “toxin” is defined in medical dictionaries as “a poison.” Therefore, its main impact on the body when ingested excessively is harmful. Heavy or binge drinking five or more days in the previous month can lead to long-term brain damage that damages other parts of the body at the same time.

Here’s How

When you consume alcohol,

  • It travels from the stomach, into the intestines,
  • Through the bloodstream to various organs,
  • In the liver, the spikes in alcohol content due to heavy drinking overload the liver’s ability to process alcohol,
  • Then the excess alcohol travels from the liver to other parts of the body like the heart and central nervous system (CNS).
  • After a while, alcohol moves through the blood/brain barrier, directly affecting the brain’s neurons. Neurons are nerve cells that send and receive signals from our brain. And there are over 100 billion interconnected neurons in the brain and CNS and,
  • Because it is a toxic substance, alcohol can damage or kill neurons.
  • In fact, research shows that sustained periods of drinking can lead to the overall shrinking of the brain.

Meanwhile, in the brain…

Alcohol is usually considered a depressant because it slows down the signals sent between neurons. Also, certain automatic brain processes like balance, breathing, and processing new information, are impaired or slowed. At the same time, alcohol causes the rapid release of neurotransmitters.

These particular transmitters are responsible for dopamine regulation in the reward center of the brain. Dopamine is a neurotransmitter that plays an important part in how you feel pleasure. It creates the warm, fuzzy feelings many people associate with drinking.

Alcoholic Blackouts

Damage to the area of the brain that is responsible for memory creation is seriously affected by drinking and “blackouts.” This can lead to short-term memory loss and the death of brain cells. Blacking out repeatedly, a clear indicator of excessive drinking can result in permanent brain damage that prevents the brain from saving new memories. You may be able to remember past events perfectly clearly but not be able to remember having the conversation a few hours later.

Alcohol-Related Brain Damage

People with alcohol use disorder (AUD) are commonly undernourished due to a poor diet. This often causes a vitamin B1 deficiency because alcohol blocks the body’s ability to absorb or use the vitamin. Almost 80% of people with AUD have a B1 deficiency and many will develop brain damage like WKS (Wernicke-Korsakoff Syndrome also called “wet brain”). Symptoms of WKS include:

  • Confusion
  • Eye muscle paralysis
  • Lack of muscle coordination
  • Damaged learning ability
  • Forgetfulness

Other Types of Damage

There are other types of alcohol-related brain damage that happen outside of the direct interactions between brain cells and alcohol. Such as:

  • People who drink are more likely to injure themselves.
  • Alcoholic hepatitis–inflammation of the liver.
  • The dysfunctional liver sends “bad” blood to the brain.
  • Fetal alcohol syndrome (FAS)–alcohol-related brain damage in infants exposed to alcohol while in the womb.

The Effects of Substance Abuse on Your Brain

Drugs interfere with the way neurons send, receive, and process signals by way of neurotransmitters. The same as alcohol.

Heroin and Other Opioids

Heroin can activate neurons in your brain because its chemical structures resemble that of a neurotransmitter in the body. This allows the drugs to attach onto and activate the neurons. And even though these drugs imitate the brain’s own chemicals, they don’t activate the neurons in the same way. They lead to abnormal messages being sent through the network.

When heroin enters the brain it is changed into morphine. Morphine has a chemical structure much like endorphins, another neurotransmitter in the brain. Endorphins act to relieve pain and this could also play a role in the feeling of pleasure. It then quickly attaches to the opioid receptors of the brain which are the neurons in the pain circuit of the brain. The feeling of pleasure is caused by the amount of the drug that is used and how fast it attaches to the receptors.

Common Long-Term Effects of Opioid Use

After continued use, heroin and other opioids change the physical structure and routine functions of the brain. Unevenness in neuron and hormone systems is created and isn’t easy to reverse. Researchers have found deterioration of the brain’s white matter which affects:

  • The ability to control behavior
  • The ability to control reactions in stressful situations
  • Increased tolerance including:
  • The need for larger or more frequent doses to produce the same results
  • An increase in physical dependence
  • Withdrawal symptoms if use is reduced or halted suddenly

In some instances, the addict loses the sensation of pleasure and uses the drug simply as a way to avoid withdrawal symptoms.

Amphetamines (Stimulants) and Cocaine

On the other hand, cocaine and amphetamines can cause the neurons to release abnormally large amounts of natural neurotransmitters. Or they may prevent the normal recycling of these brain chemicals by interfering with transporters. This also interferes with the normal communication between neurons.

The brain chemical we’re talking about is dopamine and it is associated with the control of movement and the reward system. Normally, dopamine is released by a brain cell to carry the message to another brain cell. The dopamine is then recycled back into the cell that released it. This then shuts off the messaging between the two nerve cells.

When cocaine is added, it prevents the dopamine from being recycled. This causes large amounts of dopamine to build up in the spaces between the cells which stops their communication. This flood of dopamine in the reward system of the brain strengthens the drug-using behavior. Ultimately, the brain’s reward circuit adjusts to the extra dopamine and loses its sensitivity to it. This results in the individual needing more and more just to feel an effect.

Possible Long-Term Effects of Stimulant Use

  • Malnutrition
  • Movement disorders such as Parkinson’s disease
  • Restlessness and irritability
  • Auditory hallucinations (hearing sounds that aren’t real)
  • Paranoia

Other Associated Substance Use Risks

There are other risks connected to the abuse of drugs. For one thing, drug use and intoxication can weaken your ability to make good choices. This lack of good judgment can lead to risky sexual behavior including trading sex for drugs and sharing needles. These choices increase an IV drug user’s risk of becoming infected with diseases like HIV and hepatitis C (HCV) which affects the liver.

When researchers studied the patterns of HIV infection and progression, they discovered that cocaine use actually speeds up the HIV infection. While it is speeding up the infection, it also obstructs immune cell function and promotes the spread of the HIV virus. Likewise, infection with HIV increases the risk for co-infection with HCV. Complications of the liver are common and many people who are con-infected die of chronic liver disease and cancer.

Cutting for Profit

Street drugs are often “cut” or mixed with other substances to increase the dealer’s profit. Powder cocaine sold by dealers may be up to 80% fillers. Of all the fillers that may be cut into cocaine, fentanyl is the most dangerous and is one of the main causes for the increase in overdose deaths.

Similarly, heroin is cut with other substances including fentanyl. And as is typical of black market drugs, you never know exactly what it is cut with. Common substances used include:

  • Baking soda
  • Starch
  • Powdered milk
  • Talcum powder

These substances are not safe to be snorting or injecting into your veins but some are safer than others. Some of them don’t dissolve completely in the injection solution and can cause serious problems as the particles build up or clog arteries. This can cause heart attacks, blockages in the brain, and damage to the liver.

Treatment for Alcohol and Substance Use Disorders

Depending on the severity of the brain damage, individuals may receive preventative, restorative, or end-of-life medical care. There are no cures for alcohol-related brain damage, however, early diagnosis can stop brain damage and lifestyle changes may even reverse the deterioration. Still, for all forms of substance use-related brain damage, quitting the use is the best first step.


And when you stop using your drug of choice, it is important to be in a detox program. Having medical supervision and support during withdrawal can be the difference between success and failure. And life and death. Withdrawal symptoms from certain drugs can be life-threatening.

Treatment Programs

After detox, you are ready for a treatment program. Depending on the severity of your addiction, you may enter:

Residential Program–This is the highest level of care and you will live at the treatment facility with 24-hour supervision.

Outpatient Programs–Outpatient programs allow the patient to live at home and attend therapy and counseling sessions at the treatment facility during the day. Typical outpatient programs are:

  • Partial Hospitalization Program (PHP)
  • Intensive Outpatient Program (IOP)
  • Outpatient Program (OP)

The difference in the levels of care relates to the time commitment of each program. The programs range from full days at the treatment center every day to 2 or 3 days a week for a few hours a day.


In the treatment center, you will engage in various types of therapy. Alcohol and substance use disorders typically use behavioral therapies to address the behaviors and thought patterns that help people become and remain addicted.

Group and individual counseling are also beneficial to help people discover possible reasons for substance abuse and any underlying mental health issues. If there is a co-occurring disorder, it is called a dual diagnosis and needs to be treated along with the addiction.

The First Step

So are you ready to take the first step? Or help a loved one start their journey? Substance use is a road to nowhere, whether it’s alcohol or drugs, prescription or street. Stop damaging your brain, your relationships, and your future.

Free by the Sea is a rehab in the State of Washington that can offer you the programs and therapies you need to find yourself again. We know your addiction is not the real you. Not what you intended for your life. Our caring and professional staff can get you on the path to a fulfilling life by creating a treatment program specifically for your needs. Contact us now. You have everything to gain.