Opioid addiction: what you need to know

Written by Drew Redd. Mina Draskovic, B.Psy., reviewed this content for accuracy.

Opioid addiction is a severe medical condition that involves compulsive use of opioids despite harmful consequences. As reported by the ASPE, opioid-related overdose deaths rose by 6% between 2012 and 2013.

A 2024 book, Opioid Use Disorder, claims that opioid abuse affects over 16 million globally and 2.1 million in the United States alone.

Ardu’s opioid addiction treatment center provides comprehensive, evidence-based treatment programs that bring freedom from addiction.

I recently had the good fortune to receive treatment at Ardu, and am so grateful for everyone there. All of the employees from the administration to the counselors, nurses and techs were awesome. I received the very latest in medical treatment, along with in-depth counseling and behavioral therapy, that allowed me to begin my recovery in a loving and supportive environment… thanks to Ardu Recovery Center!

—Susan H

 5/5

What are opioids?

Opioids are a class of drugs that include prescription painkillers, as well as illegal drugs such as heroin. They work by interacting with opioid receptors in your brain and body to reduce pain and produce feelings of pleasure and relaxation.

Opioids are prescribed to manage severe pain, but many people end up misusing them, chasing the high they can produce. This powerful euphoric high keeps people coming back for more, even when they know it’s harmful.

Over time, the brain gets used to the presence of opioids and needs more of the drug to achieve the same effect. This is called tolerance, and it can lead to dependence and addiction.

How do opioids affect the brain?

When you take opioids, they quickly make their way to the brain and bind to opioid receptors. Opioid receptors (mu, delta, and kappa) are specialized proteins in the brain that aid in regulating pain, emotion, and reward pathways. When opioids bind to these receptors, they activate the brain’s reward system, causing a surge of dopamine that leads to feelings of pleasure, relaxation, and well-being.

Dopamine is a neurotransmitter associated with pleasure, reward, and motivation. The surge of dopamine in the brain causes intense euphoria and feelings of extreme pleasure. What’s actually happening is the brain’s reward system is hijacked, reinforcing the desire to keep using the drug.

According to Kosten and George, the release of dopamine in the nucleus accumbens (a key region in the brain’s reward system) produces feelings of pleasure, while other brain regions create lasting memories that associate these positive sensations with the surrounding environment. They explain how “these memories, called conditioned associations, often lead to the craving for drugs when the abuser reen-counters those persons, places, or things, and they drive abusers to seek out more drugs in spite of many obstacles.”

As opioid use continues, the brain starts to adapt. It tries to maintain balance by reducing its own natural production of dopamine and other neurotransmitters. Over time, the brain becomes less sensitive to the effects of opioids, requiring higher doses to achieve the same pleasurable sensations. By the time this happens, you have already developed a tolerance to opioids.

As your brain becomes increasingly dependent on opioids to function normally, you may experience drug withdrawal symptoms when you stop using. The brain has grown accustomed to the presence of opioids and struggles to cope without them. This causes intense cravings, making it extremely difficult to quit using opioids even when you want to.

The effects of opioid drugs on the brain are so strong that they cause physical brain changes. Kosten and George reveal that “opioid tolerance, dependence, and addiction are all manifestations of brain changes resulting from chronic opioid abuse.” They also make a distinction between opioid dependence and opioid addiction.

The abnormalities that produce dependence, well understood by science, appear to resolve after detoxification, within days or weeks after opioid use stops. The abnormalities that produce addiction, however, are more wide-ranging, complex, and long-lasting.

Luckily, your brain has a remarkable capacity to heal and recover. With proper treatment, support, and time, it is possible to overcome opioid addiction and restore normal brain function, regardless of the type of opioids you become addicted to.

Ardu’s drug rehab program can help you break free from the grip of opioid addiction, providing the support, guidance, and evidence-based treatments you need to heal your brain and rebuild your life.

Why are opioids highly addictive?

Opioids are highly addictive because of their powerful effects on the brain and body. Several factors contribute to the highly addictive nature of opioids, making them a major public health concern. Here are some of the main reasons why opioids are highly addictive:

Opioids produce a powerful rush of pleasure and reward, much stronger than natural rewards. (Remember what happens to dopamine and the brain’s reward system?)
Chronic opioid use alters the brain’s reward system, making it less responsive to natural rewards and more dependent on opioids.
Over time, the brain adapts to opioids, requiring higher doses to achieve the same effects. When you stop using, your brain and body go through withdrawal which can be challenging and even dangerous. To find relief from withdrawal symptoms, many relapse and turn to the temporary relief opioids offer.
Opioids can provide temporary relief from stress, anxiety, and emotional pain, offering an escape from difficult emotions or life circumstances.
When injected, snorted, or smoked, opioids reach the brain within seconds, leading to a quick and intense high.
Opioids are widely available in both prescription and illicit forms, making them easily accessible.
Many people may not fully understand the addictive potential of opioids when they start using them, especially if they are prescribed by a doctor for pain relief.
Some people may be more genetically predisposed to addiction.
Environmental factors such as stress, trauma, and social influences can increase the risk of opioid addiction.
As you develop tolerance to opioids, you may seek out stronger opioids or combine them with other substances. This increases the risk of addiction and overdose.

The highly addictive nature of opioids, combined with their widespread availability, has contributed to the ongoing opioid epidemic, with millions of people struggling with addiction to different types of opioids.

Types of opioids

Opioids can be natural, derived from the opium poppy plant, and synthetic or semi-synthetic created in a lab. Here’s a list of different types of opioids:

Natural opiates are extracted directly from the sap of the opium poppy. This milky fluid is harvested, dried, and processed to isolate the active compounds. These opiates have been used for centuries to treat pain and other ailments.
- Morphine
- Codeine
- Thebaine
- Oripavine
Semi-synthetic opioids are made by chemically modifying natural opiates. For example, heroin is created by adding two acetyl groups to morphine, which makes it more potent and fast-acting.
- Hydrocodone (Vicodin)
- Oxycodone (OxyContin, Percocet)
- Hydromorphone (Dilaudid)
- Oxymorphone (Opana)
- Heroin (diacetylmorphine)
Fully synthetic opioids are entirely man-made in a laboratory. They mimic the effects of natural opiates but can be much more powerful. Fentanyl, for instance, is 50-100 times stronger than morphine.
- Fentanyl
- Methadone
- Tramadol
- Meperidine (Demerol)
- Propoxyphene (Darvon)
Atypical opioids interact with the brain’s opioid receptors differently than traditional opioids. They offer unique properties and a reduced potential for abuse and addiction.
- Buprenorphine (Subutex, Suboxone)
- Tapentadol (Nucynta)

Some opioids are stronger or longer-lasting than others. They also differ in how likely they are to be abused or lead to addiction. Some are used for legitimate medical purposes, such as pain management, while others, such as heroin, are illicit substances.

Regardless of the type, all opioids carry a risk of addiction and should be used with caution and under the guidance of a health care provider.

How are opioids administered?

Opioids can be administered in different ways.

Oxycodone, hydrocodone, and tramadol come in pill or liquid form and are meant to be swallowed. This is the most common method for prescription opioids used to treat pain.
Heroin or morphine can be injected directly into the bloodstream using a needle. This method produces a rapid and intense high, but also carries a higher risk of overdose and infectious diseases such as HIV, AIDS, and hepatitis.
Opioids can also be injected under the skin or into a muscle. This is done in medical settings for pain management.
Fentanyl can be administered through a patch that is applied to the skin. The drug is absorbed slowly over time, providing long-lasting pain relief.
Some opioids, such as heroin or prescription painkillers, can be snorted or inhaled through the nose. This method delivers the drug quickly to the bloodstream but can cause damage to the nasal passages over time.
Certain opioids, such as buprenorphine (Suboxone), dissolve under the tongue (sublingual) or inside the cheek. The drug is absorbed into the bloodstream more quickly than if it were swallowed.

Some of these administration methods are more commonly associated with abuse and addiction. They make it easier to recognize that someone may be struggling with opioid addiction.

If you know someone with a substance use disorder (SUD), our drug and alcohol rehab center is at their disposal. We provide the support and tools necessary to overcome addiction and build a foundation for lasting recovery.

Signs of opioid addiction

While some may be skilled at hiding the signs of their drug addiction, many people struggling with opioid misuse display noticeable changes in their appearance, behavior, and overall health. Here are the most common red flags of opioid addiction:

Physical symptoms:
- Constricted or “pinpoint” pupils
- Drowsiness or nodding off
- Slurred speech
- Itching or scratching
- Nausea and vomiting
- Constipation
- Slowed breathing
- Track marks or needle wounds
- Rapid weight loss
- Frequent flu-like symptoms due to withdrawal

Psychological and behavioral signs:
- Mood swings or irritability
- Anxiety or depression
- Confusion or disorientation
- Withdrawing from friends and family
- Loss of interest in hobbies or activities
- Neglecting responsibilities at work, school, or home
- Doctor shopping (visiting multiple doctors to obtain prescriptions)
- Stealing or borrowing money to buy drugs
- Secrecy or lying about whereabouts and activities
- Possession of drug paraphernalia (needles, pipes, etc.)

If you notice these signs in yourself or someone you care about, seek professional help as soon as possible.

What are the risk factors for opioid addiction?

Many things can contribute to someone’s risk of developing an opioid addiction. The risk factors span genetic, environmental, and psychological domains, which makes some people even more vulnerable to opioid misuse and dependence.

Risk factors for opioid addiction include:

Genetic predisposition. Studies suggest that genetic factors account for about 50% of the risk for opioid addiction. People with a family history of substance abuse or addiction may be more likely to develop an opioid use disorder.
Chronic pain. People who suffer from chronic pain conditions are often prescribed opioids for long-term pain management. Prolonged use of opioids can lead to tolerance, physical dependence, and, in some cases, addiction.
Mental health disorders. Those struggling with mental health conditions such as depression, anxiety, or post-traumatic stress disorder (PTSD) may turn to opioids as a way to self-medicate or cope with their symptoms. This can increase the risk of developing an addiction.
Early exposure to drugs. People who begin using opioids or other drugs at a young age are more likely to develop an addiction later in life. The adolescent brain is particularly vulnerable to the effects of drugs, which can interfere with healthy brain development. A 2008 study found that kids who regularly used drugs and alcohol before age 15 faced higher risks of substance dependence, early pregnancy, school failure, STDs, and criminal convictions that lasted into their 30s.
Social and economic factors. Factors such as poverty, unemployment, and lack of education can contribute to a higher risk of opioid addiction. People living in communities with limited access to resources and support may be more likely to turn to drugs as a way to cope with stress and hardship.
Peer pressure and social norms. People surrounded by others who misuse opioids or other substances may be more likely to experiment with drugs themselves. Social norms that glamorize or normalize drug use can also contribute to an increased risk of addiction.
Lack of knowledge about opioid risks. Many people may not fully understand the addictive potential of opioids when they start using them, especially if they are prescribed by a doctor for pain relief. This lack of knowledge can lead to unintentional misuse and addiction.

Addiction is a complex disease where no single risk factor determines whether someone will develop an addiction. At Ardu, we recognize the unique challenges you face with opioid addiction and offer comprehensive, evidence-based treatment programs tailored to your specific needs. Our goal is to help you overcome addiction and build a foundation for lasting recovery.

The negative effects of opioid addiction

Opioid addiction can have a devastating impact on a person’s life, affecting their physical and mental health, relationships, and overall well-being. Let’s take a look at some negative health effects of opioid addiction.

Opioids can cause life-threatening respiratory depression

Opioid medications can slow breathing, leading to shallow or irregular respirations and a condition known as opioid-induced respiratory depression (OIRD). In severe cases, OIRD results in loss of consciousness, coma, or even fatal overdose.

A 2022 study found that the preBötzinger complex and Kölliker-Fuse nucleus (important brain regions that control breathing) play key roles in generating and modulating the breathing rhythm, and their disruption by opioids can have life-threatening consequences.

Increased risk of opioid overdose deaths as tolerance develops

As the body develops tolerance to the euphoric effects of opioids, people may take higher doses to achieve the desired high. According to Kesten, et. al., after a period of abstinence, a person’s tolerance decreases, putting them at high risk of overdose if they resume opioid use at their previous dose. This increases the risk of drug overdose deaths from both prescription pain relievers and illegal opioids.

Opioid use can spread infectious diseases

A 2019 study warned that the opioid epidemic had led to a surge in infectious diseases. People often share needles or other injection equipment or engage in risky sexual behaviors while under the influence of opioids, which increases the likelihood of spreading infectious diseases.

This is a major public health concern, according to the Centers for Disease Control and Prevention (CDC). The officials warn that a “deadly consequence of the opioid crisis is increased incidence of blood-borne infections, including hepatitis B virus and hepatitis C, human immunodeficiency virus (HIV), and bacteria that cause heart infections (endocarditis).”

Opioid medicines can lead to gastrointestinal problems

Opioid medications and illicit opioids can cause severe constipation, abdominal pain, bowel obstruction, and other gastrointestinal (GI) issues. According to Indian researchers, opioids act on opioid receptors throughout the GI tract, “inhibiting gastric emptying, increasing sphincter tone, changing motor patterns, and blocking peristalsis.” They slow gastrointestinal motility and decrease blood flow to the intestines.

Cardiovascular health issues from opioid use

Both prescription and illegal opioids can cause cardiovascular issues such as heart attack, stroke, and other sometimes fatal cardiovascular events, especially at high doses. A review article published in the Journal of the American College of Cardiology states that opioids exhibit a “myriad of cardiovascular complications including hypotension, bradycardia, peripheral vasodilatory flushing, and syncope.”

Opioids can impair mental sharpness and cognitive abilities

Opioid medications can negatively impact cognitive functions such as memory, concentration, and decision-making. Van Steenbergen, et. al. suggest that opioids can have detrimental effects on tasks requiring cognitive control and coordination by reducing arousal and discomfort.

Another study demonstrated that “those with chronic pain on opioid therapy have cognitive deficits including reduced spatial memory capacity and impaired performance in working memory assessment.”

The overlap of opioid addiction and mental illness

Many people with opioid use disorder also struggle with mental disorders. People often turn to opioids as a way to self-medicate and cope with symptoms of untreated mental health conditions. Conversely, long-term opioid use can also precipitate or exacerbate mental health issues like depression and anxiety disorders.

A study published in the Archives of Internal Medicine found that respondents with a common mental health disorder (such as major depression, generalized anxiety disorder, or panic disorder) were more likely to report regular prescription opioid use compared to those without these disorders.

If you’re battling both opioid addiction and mental health challenges, Ardu has your back. Our compassionate team understands the complex interplay between substance abuse and mental illness—which often requires co-occurring disorders treatment.

Co-occurring disorders or dual diagnosis involve the presence of a mental health condition alongside addiction. It requires specialized care that can tackle both issues simultaneously. At Ardu, our dual diagnosis program uses evidence-based therapies to address the root causes of your struggles. You’ll receive personalized support, equipping you with the tools to manage your mental health and achieve sobriety.

Can addiction to opioids be lethal?

Opioid addiction can be life-threatening and fatal. One of the biggest risks is overdose, especially when opioids are combined with other depressants such as alcohol or benzodiazepines.

The lifestyle associated with addiction can increase the risk of complications, including contracting infectious diseases from needle sharing or engaging in risky behaviors to obtain drugs. Long-term opioid abuse can strain vital organs such as the liver and kidneys, potentially causing life-threatening damage. The potent nature of opioids can suppress respiratory function to dangerous levels, potentially leading to coma or death.

British researchers revealed that fentanyl may be more lethal than other opioids due to its high potency, rapid onset of respiratory depression, and induction of respiratory muscle stiffness. They also have lower cross-tolerance with other opioids such as heroin—people who have built up tolerance to other opioids may still be vulnerable to fentanyl overriding that tolerance and causing overdose.

An Austrian study found that many opioid overdose victims had lower opioid concentrations in their blood, suggesting aspiration of vomit or stomach contents into the lungs was a major contributor to the fatalities. Opioids can dangerously depress breathing and impair the gag reflex, allowing vomit to be aspirated into the lungs and cause asphyxiation, on top of the direct respiratory depression from opioid overdose.

Seek professional treatment to address the physical and psychological aspects of opioid addiction before it becomes a matter of life or death.

How to recognize an opioid overdose

When someone takes too much of an opioid drug, causing breathing to dangerously slow or stop completely. Opioid overdoses can potentially lead to brain damage or death.

Symptoms of an opioid overdose include:

Pale, clammy skin
Slowed or stopped breathing
Blue or purple tinge to lips and nails
Vomiting
Extreme drowsiness and inability to wake up
Tiny “pinpoint” pupils
Loss of consciousness and unresponsiveness

If someone shows signs of an opioid overdose, call 911 immediately and administer the overdose reversal drug naloxone if available.

Opioid addiction treatment options

Ardu Recovery Center offers a premier opioid treatment facility to help you overcome your addiction and achieve lasting recovery. Our comprehensive, evidence-based approach combines medication, therapy, detox, and aftercare services tailored to each person’s needs.

Here’s what you can expect from our opioid addiction treatment center:

Medication-assisted treatment combines FDA-approved medications with counseling for a whole-patient approach. Medications such as buprenorphine, methadone, and naltrexone are used to help reduce powerful cravings and withdrawal symptoms. Our medical team works closely with counselors to properly administer and monitor these medications as part of a comprehensive treatment plan.
For those with severe opioid addictions, our inpatient and residential programs provide a safe, supportive environment away from triggers 24/7. In our intensive inpatient treatment center, patients live on-site and participate in counseling, behavioral therapies, support groups, and holistic activities. This level of care and structure helps establish the foundations for sobriety.
Outpatient care allows more flexibility for those ready to continue treatment while living at home and working. Patients visit our facility regularly for counseling, check-ins, drug testing, and therapy sessions.
Our opioid detox center offers a safe, medically assisted detox program to help patients get opioids out of their system in a controlled environment. Our medical team provides medication and care to manage withdrawal symptoms and cravings.
We take a holistic approach to addiction treatment and detox, caring for your complete physical, mental, and spiritual well-being. Our holistic therapies such as yoga, meditation, massage, and nutritional counseling promote healing from the inside out. This whole-person philosophy cultivates resilience for lifelong recovery.
An individual counselor and a support group are powerful tools for recovery. One-on-one sessions in our individual therapy get to the root causes of opioid addiction and develop coping strategies. Group therapy provides peer support, advice, and accountability.
Addiction impacts the whole family system. Our multi-family group therapy involves loved ones in the recovery process through education, counseling, and strategies to repair strained relationships.
Cognitive-behavioral therapy (CBT) teaches patients to reframe negative thought patterns that can trigger drug use. CBT builds new coping mechanisms and life skills.
Dialectical behavior therapy (DBT), mindfulness therapy, and relapse prevention give patients tools to deal with cravings, identify triggers, and maintain motivation.
Recovery is an ongoing process, so we create plans for continued support after completing treatment. This includes alumni groups, sober living, therapy, and more.

With compassionate experts, personalized treatment plans, and a whole-person healing approach, Ardu provides the highest quality integrated care for long-term opioid addiction recovery. We can pave an easier road from detox to treatment to recovery.

Get help with Ardu Recovery Center

Our recovery center welcomes people seeking help to overcome their opioid addiction. Our dedicated team of professionals is here to guide and support you in your addiction treatment process, laying the foundation for long-term sobriety and relapse prevention.

To enroll in an Ardu opioid treatment program, contact Ardu Recovery Center online or via phone (801-872-8480). We will work with you to find a recovery path that works for you during the detox process and beyond.

Read our admissions process page for more information.

Drew Redd is the executive director of Ardu Recovery Center and is dedicated to empowering people on their journey to sobriety.

Opioid addiction FAQ

What are the 4 stages of recovery?

The four stages of addiction recovery are:

The first stage involves stopping the addictive behavior through treatment options such as inpatient rehab, outpatient programs, or medication-assisted treatment using medications for opioid use disorder like methadone or buprenorphine. Detox and managing withdrawal symptoms is part of this stage.
After getting through the physical addiction, early recovery is about developing a sober lifestyle and coping mechanisms. It focuses on abstinence from opioids, managing cravings, addressing mental health issues, and avoiding relapse triggers.
Recovery is an ongoing process of sustaining the behavioral changes and commitment to sobriety. It involves lifestyle changes, repairing relationships through family counseling, building sober supports, nurturing new meaningful pursuits, and being vigilant against complacency.
The final stage is when someone has reasserted a strong, stable sense of self and quality of life distinctly separate from any addiction identity. Recovery is integrated into daily life as a personal value and priority.

What are the 5 most common types of addiction?

The five most common types of addiction are:

Alcohol addiction. Alcoholism involves loss of control over drinking, physical dependence, and drinking in dangerous situations.
Nicotine addiction. Through smoking or vaping, nicotine has a highly addictive potential by altering brain pathways that control pleasure, reward, and mood.
Opioid addiction. Addictions to prescription pain pills like oxycodone as well as illegal opioids like heroin have spiked in recent years and have very powerful hooks.
Stimulant addiction. Drugs such as cocaine, methamphetamine, and prescription stimulants are highly addictive due to their intense euphoric effects.
Marijuana addiction. While generally less addictive than other substances, marijuana can still create psychological cravings and dependence in some users.

What are the 7 R’s of recovery?

The seven R’s of recovery include:

Re-evaluation: taking an honest look at your addiction, understanding it is a problem, and making a commitment to change.
Responsibility: you alone are responsible for your recovery and managing your disease of addiction daily.
Rendition: making amends to those you have harmed or taking steps to repair damaged relationships and trust.
Recovery: following a structured treatment plan and using tools like therapy, meetings, sponsors, etc.
Removing toxic people: letting go of relationships and situations that threaten your sobriety.
Rehabilitation: using exercise, proper nutrition, and self-care activities to rehabilitate your mind and body.
Rectifying your life: taking steps to live a positive, ethical, balanced lifestyle that supports your recovery.

What is the first rule of recovery?

The first and most important rule of recovery is admitting you have a problem with drugs or alcohol and that you need help to overcome the addiction. This initial admission of being powerless over the addictive behavior requires honesty and humility. It’s the critical first step that allows you to then accept support and treatment.

What is the most addictive behavior?

While any compulsive behavior that triggers the brain’s reward system can be addictive, addictions to certain substances are among the most addictive behaviors. Drug addictions to potent synthetic opioids such as heroin are considered highly addictive, as are stimulants such as cocaine and methamphetamine. Gambling addiction is also recognized as an extremely addictive behavior disorder.

How does addiction affect the brain?

Addiction is defined as a chronic, relapsing brain disease characterized by compulsive drug seeking and use despite harmful consequences. As a person becomes addicted, the brain’s dopamine reward pathways become altered, reducing their sensitivity to natural rewards and reinforcing the need for the substance’s dopamine boost. This throws the brain’s self-control and judgment circuits out of balance.

Over time, a person’s ability to resist cravings diminishes, making it extremely difficult to simply quit through willpower alone. Addiction causes functional and molecular changes in brain circuits involved in pleasure/reward, learning, stress, decision-making, and self-control.

Resources

Opioid Abuse in the U.S. and HHS Actions to Address Opioid-Drug Related Overdoses and Deaths. (2015, March 25). ASPE. https://aspe.hhs.gov/reports/opioid-abuse-us-hhs-actions-address-opioid-drug-related-overdoses-deaths-0

Dydyk, A. M., Jain, N. K., & Gupta, M. (2024, January 17). Opioid Use Disorder. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK553166/

Kosten, T. R., & George, T. P. (2002). The Neurobiology of Opioid Dependence: Implications for Treatment. Science & Practice Perspectives, 1(1), 13-20. https://doi.org/10.1151/spp021113

Wang, C., Chen, C., Lee, H., & Cheng, M. (2019). Opioid Addiction, Genetic Susceptibility, and Medical Treatments: A Review. International Journal of Molecular Sciences, 20(17). https://doi.org/10.3390/ijms20174294

Early Exposure To Drugs, Alcohol Creates Lifetime Of Health Risk. (2008, October 8). ScienceDaily. https://www.sciencedaily.com/releases/2008/10/081016124244.htm

Baldo BA, Rose MA. Mechanisms of opioid-induced respiratory depression. Arch Toxicol. 2022 Aug;96(8):2247-2260. doi: 10.1007/s00204-022-03300-7. Epub 2022 Apr 26. PMID: 35471232.

Kesten, J. M., Holder, E., Ayres, R., Ellis, P., Taylor, S., Hickman, M., & Henderson, G. (2022). Changes in the development of opioid tolerance on re-exposure among people who use heroin: A qualitative study. PLoS ONE, 17(6). https://doi.org/10.1371/journal.pone.0269379

Schwetz TA, Calder T, Rosenthal E, Kattakuzhy S, Fauci AS. Opioids and Infectious Diseases: A Converging Public Health Crisis. J Infect Dis. 2019 Jul 2;220(3):346-349. doi: 10.1093/infdis/jiz133. PMID: 30941402; PMCID: PMC6941614.

Infectious Diseases, Opioids and Injection Drug Use in Persons Who Inject Drugs | CDC. (n.d.). https://www.cdc.gov/pwid/opioid-use.html

Mahajan, R., Gupta, Y., Singh, A., Dhiman, P., Midha, V., Kakkar, C., Narang, V., Mehta, V., Saggar, K., & Sood, A. (2020). Clinical profile and outcomes of opioid abuse gastroenteropathy: An underdiagnosed disease entity. Intestinal Research, 18(2), 238-244. https://doi.org/10.5217/ir.2019.00104

Krantz, M. J., Palmer, R. B., & Haigney, M. C. (2021, January). Cardiovascular Complications of Opioid Use. Journal of the American College of Cardiology, 77(2), 205–223. https://doi.org/10.1016/j.jacc.2020.11.002

Van Steenbergen, H., Eikemo, M., & Leknes, S. (2019, April 8). The role of the opioid system in decision making and cognitive control: A review. Cognitive, Affective & Behavioral Neuroscience. https://doi.org/10.3758/s13415-019-00710-6

Sullivan, M. D., Edlund, M. J., Zhang, L., Unützer, J., & Wells, K. B. (2006, October 23). Association Between Mental Health Disorders, Problem Drug Use, and Regular Prescription Opioid Use. Archives of Internal Medicine. https://doi.org/10.1001/archinte.166.19.2087

Gill, H., Kelly, E., & Henderson, G. (2019). How the complex pharmacology of the fentanyls contributes to their lethality. Addiction (Abingdon, England), 114(9), 1524-1525. https://doi.org/10.1111/add.14614

Nicolakis, J., Gmeiner, G., Reiter, C., & Seltenhammer, M. H. (2020). Aspiration in lethal drug abuse—A consequence of opioid intoxication. International Journal of Legal Medicine, 134(6), 2121-2132. https://doi.org/10.1007/s00414-020-02412-y

Mina Draskovic, B.Psy., reviewed this content for accuracy on April 15, 2024