How Do Opioids Impact Your Nervous System?

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The joy, the pain – everything comes from the brain. When opioids come into the picture, it all becomes a swirling hurricane of emotions that leads to the vicious claws of addiction. Opioids impact your nervous system in many ways and each of those ways plays a major role in pain control and addiction development. Experts at luxury rehab Florida put an effort every day into improving knowledge about this impact. So, today, we’ll pass on some of this knowledge to you in order to give you all possible means to stop this vicious disease once and for all. 

What are opioids?

Opioids are a family of medications that relieve pain and induce feelings of pleasure by binding to and activating certain receptors in the brain, spinal cord, and other regions of the body. Medications like oxycodone, hydrocodone, and morphine, as well as illicit street narcotics like heroin, are all opioids since they are derived from the opium poppy plant.

We use opioids to alleviate moderate to severe pain. This includes the pain caused by cancer and other chronic diseases. They used to be a major part of pain relief strategy in American medical society. And they still are in some other parts of the world. However, in the USA today, doctors only occasionally prescribe them for post-dental or post-surgical pain relief, following strict guidelines.

A lot of opioids
Opioids impact your nervous system – don’t take them lightly.

Tolerance and addiction

The sudden drop in the use of opioids among medical professionals is quite understandable. They can be physically addictive to a great extent. This is particularly obvious when we look at the number of patients in oxycodone rehab. Also, they have a significant potential for misuse and can lead to tolerance and overdose if they are used regularly. Because of this, doctors often advise using them only temporarily and under medical supervision.

When deciding whether or not to prescribe opioids, doctors should think carefully about the pros and downsides of doing so, as well as other options for pain treatment, such as physical therapy, non-opioid drugs, or behavioral therapies. Patients should be educated on the hazards and correct use of these drugs, and they should be constantly monitored for symptoms of overuse or addiction.

Prevalence of opioid use and abuse

The widespread availability of opioids has made their misuse a major public health issue. An estimated 1.6 million Americans have an opioid use disorder in 2019, while an additional 10.1 million reported misusing prescription opioids in 2019.

Opioid abuse may result in physical and psychological dependence, as well as fatal overdose. In 2020, the number of drug overdoses reached the number of 93000 people. It’s alarming to know that more than 70 percent of them had some kind of opioid-involved. During the last several years, the incidence of fatal opioid overdoses has steadily increased. Today, a common guest in our conversations is the Florida opioid overdose epidemic. Synthetic opioids like fentanyl play an increasingly important part in it.

statistical numbers
The numbers don’t lie – Florida opioid crisis is the proof.

Addiction can enter anyone’s home

Opioid addiction affects people of all ages and stages of life. It may occur from legal prescription medication usage, illegal drug use, or even accidental exposure to opioids in a medical environment. As with every other addiction, it doesn’t discriminate. There’s no way to be in a ‘no-danger’ with opioids, as our patients at the inpatient rehab Florida program can witness. But, to decrease the risks,  there needs to be significant introspection and work on yourself being involved. Due to differences in environments during childhood and growing up, certain groups have been hit harder than others by the opioid crisis.

The neurology of pain

The nervous system is critically important in controlling the experience of pain throughout the body. Nociceptors (the infamous ‘receptors of pain’) are specialized nerve endings that are triggered by a wide range of stimuli. This includes heat, pressure, and chemicals produced by injured tissues. As pain is experienced, nociceptors send signals to the spinal cord, where they connect with other neurons. Some neurons in the spinal cord may boost or dampen the pain signal before it reaches the brain, altering the experience of pain for the recipient.

Brain areas involved in sensory perception, emotion, and cognition all contribute to the processing of the sensation of pain. Together, these brain areas process and make sense of pain signals so that the body can react appropriately. Endogenous pain control mechanisms, such as the production of natural pain-relieving compounds like endorphins and enkephalins, are other mechanisms by which the nervous system may manage pain. These compounds modulate the transmission of pain signals via the nervous system and increase sensations of calm and serenity by binding to certain receptors.

A person with the back pain thinking how opioids impact your nervous system
Different types of pain stimulate nociceptors.

Her Majesty, the synapse

The focal point of action for opioids is the neuronal synapse. Basically, it’s a gap between two parts of different neurons that serves as a communicating spot. There is a presynaptic (before the synapse) and postsynaptic (after the synapse) nerve in this communication. The presynaptic nerve sends information about the stimuli that happened by secreting neurotransmitters (communicating molecules) into the gap. The postsynaptic nerve then takes those molecules and ”reads” that information in a certain way, depending on what neurotransmitter was involved. For example, if it was glutamate (an excitatory neurotransmitter), your postsynaptic nerve will read it like ”Yes, we feel pain”. On the other hand, if it is GABA (a major inhibitory neurotransmitter in the brain), the postsynaptic neurons will read the information about the lack of pain to the stimuli.

The site of action

Opioids work on the postsynaptic neuron as well as the presynaptic nerve terminal. Opioids typically have suppressive effects at the postsynaptic level. The main impact of opioids is thought to be the inhibition of neurotransmitter release at the presynaptic level. While opioids act at several presynaptic locations on both inhibitory and excitatory neurons, their ultimate impact on the brain is due more to their postsynaptic actions. If a neurotransmitter normally produces an inhibitory effect, presynaptic inhibition of neurotransmitter release may cause excitatory effects in a target neuron.

However, the opioid may not cause excitatory effects if it also has a postsynaptic inhibitory effect on the target neuron. That’s why we came to the conclusion that the action of opioids on a neuron is determined by the location and density of opioid receptors on that neuron.

A neuron
Neuronal synapses make us alive, and their receptors determine how we behave.

Neuronal characteristics play a major part

There are numerous distinct kinds of neurons in the nervous system, each with its own unique size, shape, set of functions, and chemical makeup of released neurotransmitters. For example, when administered intravenously, morphine blocks the release of several neurotransmitters via its action on certain receptors. These include noradrenaline, acetylcholine, and the neuropeptide substance P. That’s because it influences certain receptors on certain neurons.

Physiology of hurting and the role of opioids in it

But, where does the pain start? When tissues are damaged or inflamed, they produce chemicals that stimulate the main sensory neurons. This is what causes the sensation of pain. These stimuli get picked by the nociceptors that ”shuffle” this information to the spinal cord. Dorsal horn neurons for example (neurons that stay at the back of the spinal cord) take a great part in processing pain signals. They primarily secrete glutamate and substance P. When stimulated, they send information through the spinothalamic tracts (the pathways via which the brain receives information about noxious stimuli).

However, nature made sure that we can regulate these pathways by will. So, the dorsal horn may be inhibited by descending pathways triggered by this information, which originate in the periaqueductal grey area of the midbrain.

A man with lights
Have you ever noticed how some people just ‘work through the pain’? That’s because they have strong central inhibition of the stimuli!

Receptors play a major role

Opioid receptors are found in the primary afferent neurons, spinal cord, midbrain, and thalamus, all of which play a role in pain transmission and regulation. Natural opioid peptides’ function in pain regulation remains unclear from a physiological standpoint. The endogenous opioid system, however, is activated in pathological situations.

What happens is that opioid medicines provide analgesia by activating descending inhibitory mechanisms in the midbrain. They prevent neurotransmitter release from the spinal cord’s main afferent terminals.

The discovery that sustained activation of nociceptive pathways can cause substantial changes in neurotransmitter levels in primary afferent neurons and consequent changes in sensitivity to opioid analgesia is a major step forward in our understanding of pain mechanisms. Basically, neuropathic pain is linked to decreased sensitivity to opioids, while inflammatory pain may be linked to enhanced sensitivity to opioids. Additionally, there is a theory that activation of the glutamate NMDA receptor is responsible for the alterations in pain sensitivity seen in chronic pain conditions.

Opioids and their receptors – the monopoly on pain

When an opioid binds to an opioid receptor in the brain, spinal cord, or elsewhere in the body, it triggers a chain reaction that has a variety of effects on the nervous system. Opioid receptors may be categorized into three major classes:

  • mu
  • delta
  • kappa

When an opioid molecule binds to a mu-opioid receptor, a signaling pathway is activated, and the release of neurotransmitters is suppressed. This is especially true for neurotransmitters involved in the transmission of pain signals, such as substances P and glutamate. Inhibiting neurotransmitter release results in less felt pain and greater tolerance for discomfort. Opioids have many effects on the nervous system, including pain relief. However, they can also cause euphoria, sedation, and respiratory depression. Healthcare professionals at meth rehab Florida facility suggest that the activation of other opioid receptor types, such as delta and kappa receptors, is what is responsible for these effects.

a pile of molecules in the human form
At the end of the day, we’re all just a swirling storm of molecule interactions.

Little molecules that play a great part in addiction

Opioid abuse can cause neurological changes that eventually lead to tolerance, dependence, and addiction. In order to achieve the same analgesic effect from opioids, the body develops tolerance and requires increasingly large doses. Physical dependence on opioids leads to dependence on its effects, and withdrawal symptoms may develop when opioid usage is suddenly discontinued or drastically decreased.

Opioid addiction occurs when people continue to use opioids despite harm, and this behavior is linked to alterations in brain regions that regulate reward and motivation. In order to create effective pain management techniques and to prevent and cure opioid addiction, it is crucial to have a firm grasp of the neurobiology behind opioids.

They disrupt natural neurotransmission

As we said, opioids connect to their receptors, setting off a chain reaction that eventually stops the release of neurotransmitters. That’s because opioids reduce the release of certain neurotransmitters at the brain’s synapses. Dopamine is involved in reward and motivation. Serotonin is involved in mood, appetite, and sleep regulation. Finally, noradrenaline is involved in the body’s stress response. These are all very important neurotransmitters that opioids influence.

Opioids work by both reducing the output of excitatory neurotransmitters and increasing the output of inhibitory ones like gamma-aminobutyric acid (GABA), which slows down the activity of neighboring neurons. Inhibition of pain perception, euphoria, relaxation, and slowing of body processes like respiration and heart rate are all side effects of opioids’ actions on neurotransmitters and receptors in the brain.

A happy person filled with dopamine
Cravings for dopamine lie in the middle of many addictions.

What is the mechanism of opioid addiction development?

Opioid tolerance and dependence develop when the brain and body get acclimated to the drug’s effects. This indicates that greater and higher dosages of the medication are required to provide the same effects (in this case, alleviation from pain or happiness). The brain’s reward circuit is altered to become more responsive to the medication as exposure increases. Hence, when an opioid user attempts to cut down or stop using the drug, withdrawal symptoms set in. These can be quite dramatic and include nausea, vomiting, diarrhea, muscular pains, and anxiety. Since these symptoms are far from pleasant, and euphoria waits on the other side of opioids – users usually have no doubt about which side they’ll take.

However, as time goes by, things get more and more serious. Repeated use of opioids may cause physical and psychological dependency, rendering the user unable to go on with regular life in its absence. They may feel extreme drug cravings and put forth a lot of effort to get and use the substance, even if it means putting their lives on hold. Opioids promote addiction by changing how the brain processes rewards, leading to both a physical and mental reliance on the substance.

The whole brain changes and neurons change with it

Opioid addiction is connected with a spectrum of brain abnormalities that emerge as a consequence of persistent opioid use. These alterations can play a role in the onset and maintenance of addiction, and their effects can last for quite some time.

Modifications to the brain’s reward circuitry

Opioids have the potential to create major changes to the brain’s reward center. The reward center is a network of structures that is responsible for processing and reinforcing pleasant experiences, including the use of drugs. Opioids have the ability to bind to certain receptors in the brain known as mu-opioid receptors. These receptors lay in the brain’s reward center and heavily contribute to the regulation of the brain’s response to rewards.

A person that climbed a mountain
Finding rewards for our efforts in life is what keeps us going.

A hormone of satisfaction makes it harder to quit

We mentioned dopamine before, and it’s certainly a substance to remember. Dopamine is a neurotransmitter that is linked to feelings of pleasure and reward. When opioids connect to mu-opioid receptors, it triggers the release of dopamine.  Since they trigger the release of dopamine in the brain’s reward region, opioids have a pleasant effect on the user and encourage actions that lead them to seek out more drugs. Long-term use of opioids may result in long-term alterations to the reward center of the brain, which can lead to addiction as well as other harmful effects. That’s why people addicted to opioids tend to change their behavior. They can suddenly become quite masochistic – they take rewards in different places than normal. Our patients at IOP Palm Beach reported major reverse in their behavior once they’ve gotten off opioids as a result of a positive shift back.

False ”award” overpowers the natural one

Opioids, in particular, are known to reduce the number of mu-opioid receptors and affect the release of other neurotransmitters, such as serotonin and norepinephrine, which may lead to structural and functional alterations in the reward system. These changes can lead to a dysregulated reward response, in which the brain becomes less responsive to natural rewards, such as food or social interactions, and more dependent on opioids to experience pleasure. Natural rewards, such as food or social interactions, are still able to stimulate the brain.

A group of friends discussing opioids impact on your nervous system
Addicts no longer find pleasure in social interactions.

Reward in the drug is what makes an addict

In addition, the changes that opioids produce to the brain’s reward center are critical to understanding since they play a role in the development of addiction. Addiction is a chronic condition that is defined by compulsive drug use, despite the severe repercussions that drug use may have on a person’s health, relationships, and everyday functioning. Since opioid addiction produces alterations in the brain’s reward region, it may be especially difficult to recover from. As a result, it can be tough for people to feel pleasure or reward in the absence of opioids.

That’s why our experts at Adderall addiction rehab always say that it’s crucial for the surroundings to offer compassion, instead of judgment. It’s important that the members of the family think – how would they feel in a situation where they can’t feel happy, no matter how hard they try?

Changes in brain structure

Another significant change that is very noticeable, especially in patients at heroin rehab Florida facility is a change in the gray matter of the brain. Gray matter is crucial for decision-making, impulse control, and emotion regulation. Also, new synapses in the gray matter predispose to making memories. So, when the gray matter starts losing its natural characteristics, great changes in the person’s behavior occur. Volume loss in brain areas is associated with long-term opiate usage.

So, long-term opioid use leads to impairments in cognitive abilities, including attention, memory, and the ability to make decisions. A person’s whole persona can shift due to these disruptive changes. You can see addicts making decisions they would never make in a healthy state, and that’s due to these gray matter disruptions.

A therapy session
Behavioral therapy can help with changes in behavior.

An unbalanced stress reaction

One of the most important and primal functions our nervous system has is a response to stressful situations. Opioids may disrupt the brain’s stress response system, leading to elevated levels of stress hormones and an abnormal stress response. They alter the system that regulates the body’s response to stress by (among other things) preventing the production of stress hormones like cortisol and adrenaline. By inhibiting the hypothalamic-pituitary-adrenal (HPA) axis, opioids reduce the body’s synthesis of cortisol, the stress hormone.

The HPA axis is a complex network of hormones and neurotransmitters that governs the body’s response to stress. This may result in reduced stress response and reduce the body’s capacity to deal with stress.

Fewer hormones of happiness – more stress

In addition, opioids have the ability to affect the levels of other neurotransmitters, including dopamine, serotonin, and norepinephrine. All of these neurotransmitters we mentioned before play a role in the regulation of stress and mood. Dopamine alone is a hormone of satisfaction, but together they go by the name of ”hormones of happiness”. The imbalance of opioids  may cause the stress response system to become dysfunctional. Especially the use of opioids for an extended period of time may cause alterations in the levels of these neurotransmitters. In turn, this can result in dysregulated stress responses, anxiety, and depression.

a stressed person
Stress is a common guest in addictions.

Stress-related diseases thrive in an opioid environment

Moreover, the usage of opioids may result in physical alterations to the way the stress response system in the brain functions. The amygdala, the hippocampus, and the prefrontal cortex are all parts of the brain involved in the control of stress and the processing of emotions. Chronic opioid usage has been linked to alterations in these brain regions. These alterations might impede the brain’s capacity to react effectively to stress, which in turn can raise the risk of stress-related diseases such as post-traumatic stress disorder (PTSD).

Opioids may lead to an unbalanced stress response system because they:

  • inhibit the release of stress hormones
  • affect the levels of other neurotransmitters involved in the regulation of stress
  • induce physical alterations to the brain’s stress response system

These consequences may reduce the body’s capacity to deal with stress. In turn, this raises the likelihood of developing conditions that have their roots in stress.


Opioid-induced hyperalgesia is a condition in which a person becomes more sensitive to pain after chronic opioid usage. Basically, when opioids shut down too many receptors, they become ”hungry for stimuli”. That means that, once the opioid inhibition stop – a person will feel more pain to smaller stimuli than before. As our experts at crack cocaine rehab suggest, this part of the substance-receptor mechanism is majorly responsible for the maintenance of an addiction.

A person with hyperalgesia
The more we avoid the pain, the more it will haunt us.

Opioids – a reward or a punishment?

The one thing we would like to put a real accent on since it plays a major part in the way opioids impact your nervous system is a reward center in the brain. Opioid addiction is closely linked to the functioning of the brain’s reward circuitry. The brain’s reward system is a collection of circuits that fire in response to things like eating, drinking, and interacting with other people. Inducing pleasurable sensations and reinforcing drug use, opioids activate the brain’s reward system by releasing dopamine. When an individual uses opioids repeatedly, their brain develops a tolerance to the substance and begins to link it with positive emotions.

Cravings greater than the negative effects

Those addicted to opioids may have severe cravings for the substance and may keep looking for and using opioids despite the negative effects this behavior has on other areas of their life. The drug takes over the brain’s reward center, making drug-seeking behavior more important than other rewarding activities. Addiction may develop because the reward system also has a major role in learning and memory. Even in the absence of the drug itself, the brain may learn to identify drug-related signals, such as drug paraphernalia, with the pleasant effects of the substance, leading to drug-seeking behavior.

The function of the reward system in opioid addiction cannot be overstated, as it serves to reinforce drug-taking behavior and provide pleasure and reward in response to the drug. Addiction may develop and persist in part because frequent drug use enhances the reward system’s sensitivity to opioids.

A hand with drugs
Addicts neglect the negative effects of drugs.

Vital changes in the brain

The risks that opioids present to human bran go way beyond long-term, addiction development. Our brain is responsible for many vital functions, including breathing and regulating heart work. When some chemicals start messing with these regulations, the consequences can be deadly. Respiratory depression is a common adverse effect of opioids oxygen deprivation, and mortality.

When opioids bind to their receptors in the brain stem (an area where respiratory centers lie) they tend to inhibit the activity of the neurons in the area. As we’ve mentioned before, their strong GABA influence works in favor of slowing down the function of the tissue nearby. When this happens in the brain stem, as a result, the breathing slows down and it stops being deep enough to supply the whole body with oxygen. Oxygen levels severely drop, and hypoxia (the state of low oxygen) causes severe damage to every cell in the organism. This particular state is what we call respiratory depression.

A person breathing
Oxygen is an important part of many processes in your body.

The function of respiratory musculature is also compromised

The difficulty of breathing is even greater because of the fact that opioids may weaken the muscles responsible for breathing. How are they doing that? The nervous and muscular systems go hand in hand. Muscles cannot move without proper stimulation that comes from motor neurons. Motor neurons receive the commands to send stimuli from the motor cortex of the brain. Once opioids inhibit all brain functions, that initial stimulus never comes. That’s why even respiratory muscles cannot compensate for the lower dosage of oxygen in respiratory depression.

The fatality of overdose lies in the lungs

Respiratory depression can go from mild to severe and fatal, depending on the dose of opioids involved. The more opioids a person takes, the more neurons in the respiratory center shut down, for a longer period. The time the body spends without oxygen is crucial. Once a certain limit passes, the fatal outcome is inevitable. The main cause of death due to opioid overdose is respiratory depression actually (combined with impaired function of the heart).

That’s why our experts at Florida prescription drugs addiction treatment put additional effort into educating both medical and public circles on the importance of precise prescription of these drugs. Even for people that are not abusing opioids, it’s important not to overstep the line in dosage, because, opioids impact the central nervous system and it can lead to addiction. People struggling with addiction have it even harder when it comes to stopping at a certain point and not crossing the line of the dangerous dose. 

Lungs and other organs
Your nervous system is responsible for your other vital organ systems.

It’s important to know how opioids impact your nervous system

The nervous system is the crucial part of an organism that controls our bodies. Since opioids impact your nervous system to a great extent, it’s important to know all the things this interaction can do. Addictions come from these interactions – they are the core of it. So, buckle up and soak in all this knowledge. It is the power that will help you reach a brighter future.



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