How Do Drugs Affect the Brain?

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How do drugs affect the human brain” is a question commonly asked by those grappling with addiction. Addiction (substance use disorder) is a growing concern in the United States, with data from SAMHSA (Substance Abuse and Mental Health Services Administration) indicating that over 46 million U.S. adults reported diagnosable addictions in 2021.

Using drugs disrupts and alters brain chemistry. This can influence moods, emotions, and behaviors, ultimately impacting an individual’s perception and interaction with the world.

This brief guide to addiction and the brain explores these key issues:

  • How do drugs affect the brain?
  • What do drugs do to your brain?
  • Addict brain vs. normal brain: what’s the difference?
  • How can you connect with addiction treatment in Ohio?
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The Effects of Drugs on The Brain

Using any addictive drugs can cause various effects on the CNS (central nervous system) and vital bodily functions – blood pressure, respiration, body temperature, and heart rate).

How drugs affect the brain occurs due to the disruption of a natural process. The brain is composed of vast networks of neurons. Neurons are cells in the brain that act as a switch to control the flow of information in the brain. If a neuron receives sufficient signals from connected neurons, it transmits a signal to other neurons in the network in the form of neurotransmitters – chemical messengers – that bind to receptors on the receiving neuron. This triggers changes to its functioning. Taking drugs interferes with this process by disrupting the transmission and reception of signals, as well as the processing of those signals.

Some drugs – marijuana and heroin, for instance – can mimic the structure of natural (endogenous) neurotransmitters. This enables marijuana and heroin to bind to and activate neurons. That said, these drugs do not activate neurons in the same way as endogenous neurotransmitters, provoking abnormal messaging within the brain.

Drugs like cocaine and amphetamine – CNS stimulants – can trigger an excessive release of chemical messengers or prevent neurotransmitters from being properly recycled within the neural network. Again, this disrupts the normal process of communication between brain cells, distorting or amplifying neural signaling.

Beyond this, drugs can influence the level of the following neurotransmitters in the brain:

  • Dopamine: Dopamine is a neurotransmitter associated with regulating mood, motivation, movement, pleasure, and attention. Drugs like marijuana, opioids, MDMA, cocaine, meth, and PCP can all impact dopamine levels in the brain.
  • GABA: GABA (gamma-aminobutyric acid) is a naturally occurring tranquilizer that reduces stress levels and anxiety, while at the same time slowing down the CNS. Benzodiazepines like Xanax and Klonopin can affect GABA levels in the brain.
  • Serotonin: Serotonin is a chemical messenger that is responsible for stabilizing mood and regulating emotions. MDMA and hallucinogens can influence serotonin levels in the brain.
  • Norepinephrine: Norepinephrine, like adrenaline, is involved in the body’s innate fight-or-flight response, speeding up the CNS and enhancing attention, focus, and energy levels. Opioids and MDMA impact levels of norepinephrine in the brain.

Beyond this, different drugs have specific effects on the brain. Read on for a snapshot of some of the main drugs of abuse and the psychological effects associated with these substances.


Cocaine is a powerful stimulant drug that affects the brain and body in various ways. When consumed, it increases the levels of dopamine, a neurotransmitter associated with pleasure and reward, in the brain. This leads to intense feelings of euphoria and energy. However, cocaine also constricts blood vessels, raises heart rate and blood pressure, and can cause potentially life-threatening cardiovascular effects. Prolonged use can lead to addiction, changes in brain structure, and an increased risk of stroke or heart attack.

Heroin and Other Opioids

Heroin and other opioids, including prescription pain medications like oxycodone and fentanyl, bind to mu-opioid receptors in the brain, blocking pain signals and producing a sense of euphoria. These drugs depress the central nervous system, slowing down heart rate, respiration, and other vital functions. Opioid use can lead to respiratory depression, sedation, and a high risk of overdose. Prolonged use can result in dependence, addiction, and significant changes in brain chemistry.

Cocaine and Other Stimulants

Stimulant drugs like cocaine, methamphetamine, and prescription amphetamines impact the brain and body by increasing levels of dopamine, norepinephrine, and serotonin. Effects of amphetamines on the brain and effects of other stimulants include heightened alertness, energy, and euphoria. However, the use of these drugs can also cause elevated heart rate, blood pressure, and body temperature. Long-term stimulant abuse can result in severe cardiovascular problems, stroke, psychosis, and addiction.


Benzodiazepines, such as Xanax and Valium, act as sedatives and tranquilizers, enhancing the effects of the neurotransmitter GABA in the brain. They produce a calming effect and can be prescribed for anxiety and sleep disorders. However, these drugs can also cause sedation, impaired coordination, memory problems, and respiratory depression. Misuse or long-term use can lead to dependence, addiction, and severe withdrawal symptoms.


Fentanyl is a potent synthetic opioid that is many times stronger than heroin or morphine. It binds to opioid receptors in the brain, producing intense analgesic effects. Fentanyl depresses the central nervous system, leading to slowed breathing, sedation, and a high risk of overdose. Its potency makes it particularly dangerous, as even small amounts can be lethal. Prolonged fentanyl use can result in addiction, respiratory depression, and serious health complications.

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How do drugs affect the brain of a teenager?

Drugs can have a profound impact on the developing brain of a teenager. They can disrupt brain chemistry, impair cognitive function, hinder memory and learning abilities, and increase the risk of mental health disorders.

How do prescription drugs affect the brain?

Prescription drugs can affect the brain by interacting with specific neurotransmitters and receptors. They can alter the balance of chemicals in the brain, leading to changes in mood, cognition, and behavior. In some cases, prescription drugs can also be addictive and have potential for misuse or abuse.

How do drugs influence behavior?

Drugs can influence behavior by affecting the brain’s reward system, altering perception, impairing judgment, and inhibiting impulse control. The brain on drugs can lead to changes in mood, emotions, and motivation, which can ultimately impact an individual’s actions and decision-making.

What psychological factors influence the effects of drugs?

Several psychological factors can influence the effects of drugs, including an individual’s mental health, personality traits, genetic predisposition, and past experiences. Co-occurring mental health disorders, such as anxiety or depression, can interact with drug use and influence how a person responds to drugs. Additionally, psychological factors such as stress, trauma, and peer influence can also play a role in drug effects and addiction vulnerability.

A woman sits looking out at a sunset to represent what drugs do to your brain in Cincinnati, Ohio.

Get Treatment for Drug Addiction at Ohio Recovery Centers

At Ohio Recovery Centers, we specialize in the intensive outpatient treatment of all types of drug addictions. Research suggests that most mild and moderate drug addictions respond just as well to intensive outpatient treatment as residential rehab.

Our outpatient treatment programs and IOPs (intensive outpatient programs) provide those with addictions with a flexible, affordable pathway to sustained recovery.

All Ohio Recovery Centers treatment programs utilize a combined pharmacological, behavioral, and holistic approach. Treatment will equip you with relapse prevention skills, coping strategies, and ongoing therapy if needed.

Call 877-679-2132 today for immediate assistance.

Table of Contents

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Joseph Gilmore

Joseph Gilmore has been working in the addiction industry for half a decade and has been writing about addiction and substance abuse treatment during that time. He has experience working for facilities all across the country. Connect with Joe on LinkedIn.
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Christopher Glover CDCA

My name is Christopher Glover, and I am from Cincinnati, Ohio. I am currently in school and working to grow in competence to better support our community. As a recovering individual I know the struggles that you or a loved one can go through and that there is help for anything you may be struggling with.

The hardest part is asking for help and we are here as a team to best support you and your decision to start your journey towards a better future. Connect with Chris on LinkedIn

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Amanda Kuchenberg PRS CDCA

I recently joined Ohio Community Health Recovery Centers as a Clinical Case Manager. I am originally from Wisconsin but settled in the Cincinnati area in my early 20s.  My career started in the fashion industry but quickly changed as I searched to find my drive and passion through helping others who struggle with addiction. 

As someone who is also in recovery, I wanted to provide hope, share lived experience, and support others on their journey.  I currently have my Peer Recovery Support Supervision Certification along with my CDCA and plan to continue my education with University of Cincinnati so I can continue to aid in the battle against substance addiction. Connect with Amanda on LinkedIn.

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Patrick McCamley LCDC III

 Patrick McCamley (Clinical Therapist) is a Cincinnati native who has worked in substance use disorder/co-occurring mental health disorder treatment since 2019. Patrick received his bachelors degree in psychology from University of Cincinnati in 2021 and received his LCDC III (Licensed Chemical Dependency Counselor) license from the Ohio Chemical Dependency Professionals Board in 2022. Patrick has worked in Clinical Operations, Clinical Case Management, and Clinical Therapy throughout his career.

Patrick has tremendous empathy and compassion for the recovery community, being in recovery himself since 2018. Patrick is uniquely qualified to be helpful because of the specific combination of his academic background and his own experience in recovery.

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Bill Zimmerman CDCA

Bill Zimmerman is a Greater Cincinnati Area native who has worked in substance use disorder/co-occurring mental health disorder treatment since 2018. Bill received his (Chemical Dependency Counselor Assistant) license from the Ohio Chemical Dependency Professionals Board in 2020.

Bill has worked in Clinical Operations in both support and supervision, and Program facilitating and 12 step recovery support during his career. Bill has a passion for the recovery community, having been in recovery himself since 1982. Connect with Bill on LinkedIn

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Taylor Lilley CDCA, PRS

Growing up in Louisiana with addiction running rampant on both sides of my family. A life away from drugs and alcohol seemed impossible for someone like me. I remember what it was like sitting across from someone thinking there is no way they could ever understand what I was going through.

Sharing my experience offers a credibility and a certain type of trust with clients that only someone who has walked down this road can illustrate. To immerse myself further into the field of addiction, I am currently studying at Cincinnati State for Human and Social Services.  I hope I never forget where I came from, if I can do it, so can you!

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Thomas Hunter LSW

Hello my name is Thomas Hunter. I was born and raised in Cincinnati, Ohio. I am a licensed social worker.In my scope of practice I have worked in the areas of mental health and recovery for thirty years. The clients I have worked with in my career have ranged in age from seven to seventy.

I strive each day to serve my purpose of helping those in need and I believe I do so by utilizing all of my experiences to accomplish my goal of supporting those who desire to establish their sobriety and maintain it in their recovery. Connect with Thomas on LinkedIn.

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Mary D.Porter,LICDC

 My name is Mary D. Porter. I received my Masters of Social Work in 2008 from The University of Cincinnati. I received My Licensed Independent Chemical Dependency Counselor Licensure in 2001. I retired from The Department of Veteran Affairs Medical Center on April 14, 2014. Currently, I am the Associate Clinical Director for The Ohio Community Health Recovery Centers in Cincinnati.. Due to the fourth wave of the Opioid Epidemic in 2019,  I decided to enter back into the workforce to assist the addicted population.

The overdoses were astounding and I wanted to help.  I consider myself  to be an advocate for the addicted population. My compassion, resilience, empathy, wisdom, knowledge, experience and  love I have for this forgotten population goes beyond words. I consider what I do for the addicted population as a calling versus a “career,” because I too was once an “addict and alcoholic.” Today I am 45.5 years alcohol and substance free.

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Ben Lemmon LCDC III

Hello, my name is Ben Lemmon, and I’m the Vice President and Clinical Director at Ohio Community Health Recovery Centers. I’ve been working in the addiction and mental health field since 2013 and decided to enter the field after overcoming my own challenges with addiction.

When I first meet a client, I always explain to them that the reason we are meeting is because they are not capable of obtaining or maintaining sobriety, and my goal is to create a person that can maintain sobriety. I believe a person’s personality is made up of their thoughts, feelings and actions and my job is to help clients identify the thoughts, feelings and actions that have them disconnected from recovery and provide them with the tools to live a healthy and happy life. Connect with Ben on LinkedIn