“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?

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
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
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
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.

FAQ
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.

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.