We Have Beds Available! Call for Same Day Admission.855-722-6926

Addiction & The Brain: How Drugs Affect the Brain

Addiction & The Brain: How Drugs Affect the Brain

When many people talk about addiction, the first thought that comes to mind is often the health problems.

While a substance abuse problem can lead to a visible decline in mental health or physical appearance, there is a lot more going on behind the scenes. Along with the physical health repercussions of long-term drug or alcohol abuse, prolonged use of these substances can literally mess with your mind. Addiction isn’t just a bad habit or some risky choices; it is a disease that can actually alter the chemistry of the brain.

The Effects of Addiction on the Brain

If you have ever suffered from addiction, you know that it feels like your drug or alcohol cravings are controlling you. In fact, there is some truth to this. Drugs affect the brain in several ways, including chemical and physical changes that can have lasting effects on a person.

How Addiction and the Brain Are Connected

The brain is a complex system of special cells called neurons that communicate with each other through chemicals called neurotransmitters. These communications and connections control your thoughts and behaviors. Addiction occurs when drugs alter the levels of neurotransmitters in the brain and the person comes to crave these changes.

In some cases, drugs will mimic neurotransmitters and cause scrambled messages in the brain. In other cases, abused drugs flood your brain with a larger amount of dopamine, the neurotransmitter that is associated with feelings of pleasure, than normal. Dopamine is involved in the brain’s reward system, so the sudden influx of dopamine from drug use reinforces this behavior. Because the brain likes pleasurable activities, it will make the connections that lead to more dopamine, making it easier to repeat. With time, prolonged drug and alcohol use will create such strong neural connections in the brain that makes it hard to stop. Also, the brain’s ability to experience pleasure from natural rewards is reduced.1 The result is an altered brain that is addicted to the substance being abused. These chemical changes are why quitting drugs or alcohol is so hard for people who are addicted, and why most people need the help of an addiction rehab center in order to stop.

Changes to the Brain from Addiction

Not only can the neural connections of the brain be altered by drug or alcohol use and cause dependence, but drugs can also affect the size of the brain area, the amount of brain activity, and the health of brain cells.

Drugs affect the brain by shrinking or enlarging sections. Research shows that frequent drug users have changes in volume in the frontal cortex, the brain area associated with logical and higher-level thinking, depending on the drug(s) being abused.2 Other studies suggest that drug abuse enlarges the basal ganglia; the brain area associated with motor movements, learning, and emotion.3

Along with structural changes, drug addicts and alcoholics may also show abnormal levels of brain activity. A study on methamphetamine users found that they had decreased brain activity in the prefrontal cortex that relates to decision making.4 This may be part of the explanation as to why addicts often engage in risky behavior.

Also, addiction can affect the overall health of the brain. Research shows that substance abuse can damage the health and function of brain cells.2 Even if they complete a drug detox and stay sober, this could cause lasting damage to the person.

Resulting Changes from Brain Alterations

Drugs affect the brain in several ways physically, but it doesn’t stop there. As a result of these physical alterations, mental and behavioral changes often follow. Many addicts will engage in unusual behavior or act differently than their loved ones expect. This may be a result of changes in their brain from drugs and alcohol. Various addiction therapies may help retrain the brain and get the recovering addict’s behavior back to normal.

If you or someone you love is addicted to drugs or alcohol, get help now. Because of the brain changes from prolonged substance abuse, the longer you wait to quit, the harder it will be and the greater the risk of long-term damage.

Call Banyan Detox Stuart today at 888-280-4763 to learn more about how we may be able to help.


  1. NCBI - Dopamine in drug abuse and addiction: results from imaging studies and treatment implications.
  2. NCBI - Imaging the Addicted Human Brain
  3. NCBI - Quantitative morphology of the caudate and putamen in patients with cocaine dependence.
  4. NCBI - Behavioral and functional neuroimaging evidence for prefrontal dysfunction in methamphetamine-dependent subjects.
Alyssa, Director of Digital Marketing
Alyssa, Director of Digital Marketing
Alyssa is the National Director of Digital Marketing and is responsible for a multitude of integrated campaigns and events in the behavioral health and addictions field. All articles have been written by Alyssa and medically reviewed by our Chief Medical Officer, Dr. Darrin Mangiacarne.
Addiction & The Brain: How Drugs Affect the Brain
This website uses cookies to improve your experience. By using this website you agree to our Online Privacy Policy.
Learn more ›