How Drugs Affect the Brain & Central Nervous System

Written by Theresa Valenzky

& Medically Reviewed by Benjamin Caleb Williams, RN

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Last Updated - 10/06/2023

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Updated 10/06/2023

Drug use increases the risk of irreversible brain damage, but getting treatment can help you stop using drugs and lower the risk.

Most people know drugs are harmful, but how do they affect your brain and central nervous system? Understanding how drugs affect you can help you anticipate drug use and withdrawal symptoms and their potential complications.

Central Nervous System Overview

The central nervous system (CNS) is made up of the brain and the spinal cord. This system sends and receives signals from nerves throughout the body, allowing you to sense what is around you and move your muscles. The central nervous system is incredibly complex, allowing for intricate thoughts, emotions and the concept of self. Ultimately, this system is responsible for making you unique.

In addition to the conscious neurological processes the central nervous system controls, it also regulates many subconscious processes. This system controls your heart rate, breathing rate, blood pressure, sleep cycle and many other functions you don’t regularly have conscious control over.

Effects of Drugs on the Brain and Neurotransmitters

Drugs typically impact the brain by affecting neurotransmitters. Neurotransmitters are chemicals released by one brain cell at a connection with another brain cell and activate receptors on the second cell. This impacts how the brain processes information and functions.

Drugs work by artificially activating brain receptors. This makes the receptors hyperactive, increasing their effect far more intensely than under natural conditions. The intensity of different drugs differs based on the type of neuroreceptors they interact with.

Drugs That Affect the Nervous System

Many drugs can affect the central nervous system. The effects of each drug depend on the different neurotransmitters they activate.

Alcohol, Benzodiazepines and Other Depressants

Alcohol and benzodiazepines work by stimulating GABA receptors. When activated, these receptors suppress other brain signals. Using these substances results in suppressed brain signals, causing relaxation while slowing many of the body’s normal processes.

This effect causes many of the symptoms associated with the use of alcohol and other similar depressants. Symptoms like slurred speech, decreased coordination, forgetfulness or even low heart rate and breathing occur because the hyperactive GABA receptors suppress brain signals in the central nervous system.


The active ingredient of cannabis, or marijuana, activates cannabinoid receptors. These receptors are primarily present in the hippocampus and orbitofrontal cortex. These brain areas help people form new memories, maintain attention and process sensory perceptions. When these receptors are artificially stimulated, it can change how the world is perceived and induce a relaxed state; however, it can also impact memory and the ability to learn.

Cocaine, Methamphetamine and Other Stimulants

Cocaine, methamphetamine and other stimulants activate brain receptors that increase the speed and intensity of brain signals. While multiple central nervous system receptors may be affected, dopamine receptors are the main type impacted.

Using stimulants causes hyperactivity along with a feeling of invigoration and ability. It also strongly impacts the body’s normal processes, increasing heart rate, blood pressure, respiratory rate and other physiological processes. This can cause strain on the body which could be dangerous.

People who use stimulants will typically have a period of hyperactivity where they feel very focused and powerful. They often push themselves beyond what they would normally be capable of without getting tired. A crash follows this period as the effects of the drug wear off, and the period of hyperactivity causes extreme tiredness and fatigue.


Ecstasy is the commonly-used name for the drug MDMA. MDMA uniquely affects the central nervous system, impacting serotonin, dopamine and norepinephrine receptors. This results in a psychedelic and stimulant effect. Because it causes an altered perception of reality and increases energy, Ecstasy is a popular party drug.

LSD and Other Hallucinogens

LSD and hallucinogens are often referred to as psychedelics. These drugs work on many receptors but are primarily thought to work by affecting serotonin receptors. These drugs create a disconnect from reality, often called a “trip.” This experience can differ significantly each time the drug is used and can be a very pleasurable experience or very unpleasant.

Unlike most other drugs, these drugs don’t just affect how you perceive events; they can completely detach you from your environment and cause you to experience a different reality.

Opioid Drugs

Opioid drugs are a type of depressant drug and work by stimulating opioid receptors. Like the GABA receptors that alcohol and benzodiazepines affect, opioid receptors also suppress brain signals. The effects, however, are somewhat different because the receptor type is different. Specifically, opioids cause more physical relaxation than mental relaxation.

The effect of opioids makes them a commonly-used medication for treating severe pain. Opioids can, however, be quite dangerous as they can easily cause relaxation that leads important functions like breathing to slow to dangerous levels or even stop entirely.

Long-term Damage to the Nervous System

Drugs can cause long-term damage to the central nervous system in many ways. All drugs over-activate neuroreceptors in the brain. When this occurs repeatedly and frequently, the brain adjusts for constant over-activation by decreasing the sensitivity of the receptors, leading to a more normal activation level while using the drug.

However, when the drug is stopped, the receptors are not as active as they should be. This causes withdrawal symptoms until the receptors readjust.

Another type of long-term damage can occur when drug use rewires the brain. Over time, more than just the neuroreceptors are affected. The brain can actually change its structure to make someone want the drug. This effect causes cravings after withdrawal and is what drug rehab is designed to treat.

In addition to brain changes caused by a drug, some drugs can also cause other physical changes that damage the brain. For example, overdosing on opioids can lead to decreased oxygen, affecting brain health and function.

Using stimulants excessively can also cause problems like a stroke, which can lead to permanent brain damage. There are many ways that using different drugs can cause problems that lead to permanent brain damage.

Signs It’s Time To Seek Treatment for CNS Damage

The best way to take care of central nervous system damage is to prevent it from happening in the first place. Often damage to the brain is irreversible, and preventing it is far better than treating it after it develops.

If you have signs that drug use is affecting your central nervous system, you should stop using the drug as soon as possible. Potential signs that drugs are negatively affecting your brain can include:

  • Memory problems
  • Difficulty learning
  • Problems talking
  • Decreased coordination
  • Hallucinations
  • Moods changes, such as depression or anxiety
  • Tolerance of the drug
  • Cravings for the drug

These signs are especially concerning if they occur while you are not actively using the drug.

Find Help for Substance Misuse & Addiction

Substance addiction isn’t just behavioral; it causes actual changes to your brain. People often need professional treatment to get through withdrawal and stay sober as the brain relearns how to function without drugs. At The Recovery Village at Palmer Lake, we have extensive experience helping people avoid the progression of brain damage by putting a stop to drug use.

If you or your loved one are struggling to quit using a drug, now is the time to act. Continual drug use increases the risk of irreversible brain damage, but it may be mitigated with proactive treatment. The Recovery Village Palmer Lake can help you overcome addiction with evidence-based treatment programs, including inpatient rehab, partial hospitalization and mental health services. Contact us today to see if we can fit your needs and start your journey to achieving lasting recovery.

View Sources

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National Institute on Drug Abuse. “How does cocaine produce its effects?”&a[…];g[…] its effects?” May 2016. Accessed March 21, 2023.

National Institutes of Health. “Protein structure reveals how LSD affect[…]cts the brain.” February 14, 2017. Accessed March 21, 2023.

National Institute on Drug Abuse. “What are MDMA’s effects on the brain?”[…]on the brain?” September 2017. Accessed March 21, 2023.

National Institute on Drug Abuse. “Opioids”>Opioids.” 2023. Accessed March 21, 2023.

Enevoldson, T. P. “Recreational drugs and their neurologica[…] consequences.” Journal of Neurology, Neurosurgery and Psychiatry. 2004. Accessed March 21, 2023.

Gould, Thomas J. “Addiction and Cognition”>.” Addiction Science and Clinical Practice. December 2010. Accessed March 21, 2023.


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