Effects of Drug Use on the Brain

The brain is the most intricate organ in the human body. Anything we consume, ingest or inhale can affect the way our brain operates. The effects of drugs (both prescription and illegal) can have an intense influence on the brain’s overall function. Some drugs can cause irreversible damage to the makeup of the brain, along with deterioration to other main organs in the body. 

Understanding the changes that drugs have on the overall composition of the brain is imperative to those who have been both directly and indirectly affected by those who have taken drugs. If you are on the road to long-term recovery, understanding ways that your brain has been changed allows you to fully gauge how to mitigate risks associated with the changes in the future.


How do drugs work on the human brain?


In the most basic sense, drugs affect the brain by 

  • changing moods, 
  • altering emotions, and 
  • uprooting basic human behavior. 

Due to this, the way that a person, using drugs, interacts with the people, and the world, around them is altered dramatically. Drugs affect the way our brain sends, receives, and transmits information through our body. Drugs create an imbalance in neurotransmitters that are in charge of key components of both emotion and behavior. These include the most commonly known neurotransmitters, dopamine, and serotonin, which are in charge of mood regulation and emotional stabilization.


 Other imbalances are noted in gamma-aminobutyric acid and norepinephrine, which regulate things such as stress control and the flight, fight, or freeze human defense mechanism. When any of these neurotransmitters are at an imbalance, the brain function decreases and reacts to basic human situations in off-kilter ways, causing adverse human interactions and negative personal choices.


What part of the brain is affected by drug use?


The parts of the brain most affected by drug use are the cerebral cortex, the brainstem, and the limbic system. The cerebral cortex is known as the “deep thought” section of the brain used for decision making, information processing, and problem-solving details. The brain stem is in charge of the basic, but crucial, life requirements such as sleep, heart rate, and breathing. The limbic system ties into the neurotransmitter and is in charge of emotional response and your personal happiness controls. 


Why do different types of drugs have different effects on the brain and body?


Drugs are made up of different chemicals, some of which are already found within our natural brain and body. Based on the type of chemical makeup, our brain reacts differently to the signals it receives from the added chemicals when drugs are ingested. 


For example, heroin and marijuana have similar chemical makeups when compared to our naturally occurring neurotransmitters. Due to this, these drugs dupe our brain receptors and activate certain cells within our nervous system to send out faulty messages. This results in the “high” feeling people experience when using these drugs. Alternately, drugs such as cocaine or methamphetamines cause the nervous system to release excessive amounts of neurotransmitters which results in more of a jolted “high” feeling.  


How do people get addicted to drugs?


A majority of illicit and prescription drugs target a person’s neurological reward circuit. Drug use incites higher levels of positive neurotransmitters leaving users feeling exceptionally euphoric and pleased. Due to this, continued use is often associated with the feelings people get when they take the drug. Oftentimes, surges of neurotransmitters in the brain lead to the brain seeking additional surges of the same kind. This request from the brain leads people to continued use over time. After constant drug use, the brain lessens the reaction to the surge causing someone to feel less of a high over time, thus, in most instances, causing them to increase the volume of drugs they take to receive the same type of “high.”  



How is the brain changed after prolonged drug use?


Long-term drug use can have negative effects on a person’s overall brain. Based on changes in a person’s brain chemicals, they can experience symptoms that affect their judgment to make sound decisions, the ability to learn new things, level of control over stress or emotions, or ability to remember simple tasks based on an increased risk of memory loss. The amount of side effects from drug use increases based on the length of time using drugs. The type of drug also plays into the factors related to brain and chemical changes noted within patients, along with biological and genetic makeup factors. 


Substance use disorder is a chronic disease causing a person’s brain and chemical makeup to be altered by the chemicals found in drugs such as heroin, marijuana, or cocaine, along with many others. Understanding the effects that drugs have on the human brain will allow you to make informed decisions for your life or the life of someone you care deeply about. If you find yourself struggling with drug addiction, please don’t hesitate to reach out to us today. We want to get you on the path to long-term recovery now. 


About the author:

Melissa Pena is the Clinical Director at Baystate Recovery Center in Beverly, MA. She has been in the psychology field for 7 years and has been working in the substance abuse field for 3.5 years. She has a Masters’s degree in Mental Health, an Advanced Degree, and is a Licensed Mental Health Counselor. She has experience with every age group and experience with both men and women.