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Drugs Of Abuse: What Are The Most Addictive Types Of Drugs?

Last Updated: February 4, 2022

Reviewed by Michael Espelin APRN

There are many types of drugs and not a single one of the 24 million addicts in the country started using them with the intent of becoming such. Some try the most dangerous drugs under peer pressure, thinking it will only happen once, while others resort to them to suppress unpleasant emotions or symptoms of mental disorders. In 2018, the illicit drug use in the United States was reported to be 11.7%. Additionally, others are born into this addiction and abuse environment, in which drug usage is prevalent, where family members can abuse or be addicted to substances. There are no set criteria at present to establish whether someone is likely to start abusing or become addicted to a controlled or illicit substance.

What Are Drugs Of Abuse?

There are different types of drugs: prescription and over-the-counter. Whatever procurement restriction it is, keep in mind that each drug has its effect. Over-the-counter medications like Benadryl can be used to alleviate allergies. However, 69% of the pharmacists in the United Kingdom agree that this antihistamine can strongly cause addiction. On the other hand, prescription medications given by medical doctors can truly help manage certain chronic illnesses like depression and schizophrenia. However, not all of these antidepressants and antipsychotics are equally good. For example, selective serotonin reuptake inhibitors (SSRIs) are more preferred than benzodiazepines in treating depression because they promote lesser side effects and addiction potential.

According to the Centers for Disease Control and Prevention, in 2018, the rate of nonmedical use of psychotherapeutic substances in the United States was 2%. Aside from the drugs of abuse mentioned above, some of the other most addictive types of drugs include narcotics, stimulants, and hallucinogens.

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Controlled Substances: What Are The Most Dangerous Drugs?

The type of substance is the key to the issue of drug addiction. OTC medications, like Aspirin, have a very low addiction potential because their physiological effects are minimal, and sometimes not particularly positive (Aspirin causes stomach acid). Marijuana and stronger painkillers, on the other hand, bring about feelings of relief, calmness, and other desirable sensations, and their addiction potential is higher, especially when taken with alcohol. A user can become dependent on these drugs of abuse very easily.

Hence, one of the ways to divide drugs into categories is according to their addictive properties. In the United States, there are five groups of scheduled substances where the most dangerous drugs are classified.

Schedule I Drugs

Schedule I controlled substances generally have no accepted medical use in the United States. This means that these most dangerous drugs lack information or research about their safety even when used under the supervision of a doctor. Also, substances belonging to this schedule have a high potential for abuse.

Some of These Most Addictive Drugs Include:

Take note that Schedule I substances are the most addictive drugs of all drug schedules. They are highly addictive and can promote severe mental and physical dependence. For patients who want to wean off these most dangerous drugs, considering resources such as rehab centers would be of great help.

Schedule II Drugs

Schedule II substances also have a high potential for abuse and dependence. However, this time, these most dangerous drugs have accepted medical uses in the United States under severe restrictions. This means that they are still considered dangerous and must not be administered at home.

Some of the Most Addictive Drugs Belonging to This Drug Schedule Include:

Most of the Schedule II substances are opioids and narcotics. Medical doctors from Connecticut report that these substances activate the powerful reward centers in the brain of the patient. Thus, when a patient gets to feel these temporary rewarding effects, the patient will crave more of them because dangerous brain structure changes may have already occurred, which is indeed dangerous.

Schedule III Drugs

Schedule III chemicals have a lesser abuse potential than schedule I and II medications. Their dependence potential may be considered from moderate to low. Usually, these medications contain less than 90 mg of codeine.

These include:

From the list above, it can be observed that steroids are also considered dangerous substances. This means that national athletes who use these types of drugs must understand that these medications might cause addiction and may potentially produce false-positive results on drug tests. Thus, those who want to seek help during drug testing may consider resources such as drug intervention treatment.

Schedule IV Drugs

Schedule IV substances have a lower potential for abuse and dependence compared to Schedule III substances. Moreover, these substances have accepted medical use at the national level and these include the following:

Although these substances have low abuse and dependence potential and can be taken at home, misuse of these medications can lead to addiction. As cited in the medical research, benzodiazepine use disorder can develop when these substances are used long-term and administered on higher doses.

Schedule V Drugs

Compared to the other controlled substances schedule, schedule V chemicals have the lowest abuse and addiction potential. They also impose the lowest risk of dependence. Generally, these products can be used at home and for antidiarrheal, antitussive, and analgesic purposes.

These include:

  • Robitussin AC
  • Phenergan with Codeine
  • Ezogabine
  • Lyrica
  • Lomotil

Again, the misuse of these medications is the culprit why addiction occurs. Even though they have limited mental and physical abuse and dependence, patients who find themselves struggling in stopping their use are advised to seek help resources such as drug intervention programs.

Other Risky Drugs And Substances

Other substances come with abuse and addiction potential and some of these might not be included in the DEA drug scheduling. Usually, these medications are anxiety medications, antidepressants,  and plant-derived substances.

For More Information, Take a Look at the List of the Other Most Addictive Drugs:

The drugs above can be prescribed by a doctor only.

They are effective in managing anxiety and depression. However, even though they are regulated, abuse in the use of them can lead to addiction and dependence, especially when taken with alcohol. In case patients experience this, considering resources such as rehab centers, even during this time of the pandemic, might be of great help.

Drugs Effects On The Body Systems: Dangers Of Addictive Drugs

When medications are intently consumed out of a doctor’s instruction, that is merely substance abuse. Even though psychoactive substances mainly act on the brain, abuse in the use of these substances can impose severe dangers to the other body systems. For example, based on the research, if not fatal, abusing heroin may damage the reproductive system and brain of its users as this drug can promote impotence and mental retardation.

In this section, topics about the effects of drug abuse on the brain, heart, liver, lungs, kidneys, and sexual health will be elaborated on.

Drug Use and Effects on the Brain

When incidental use of the most dangerous drugs has become drug addiction, certain release patterns will form. With time, the brain begins to release less and less pleasure-inducing neurotransmitters (mainly dopamine and serotonin), motivating the user to take higher and higher amounts to be able to experience the same effects.

When This Continues, It Will Cause the Following Dangers to the Brain:

  • Brain structure changes
  • Reduced sensitivity of brain systems
  • Inability to make decisions
  • Unregulated emotions and actions
  • Memory loss
  • Behavioral problems

Based on the source stated above, when the brain structure changes, patients become more vulnerable to substance abuse disorder. Thus, rehab centers are highly recommended for struggling patients. After this, enrolling in sober living homes can improve the recovery process of patients.

Drugs Effects on the Heart

The American Heart Association considers illegal substances, especially cocaine, heart-attack drugs. When they are abused, they cause effects on the heart functioning.

Some of These Include:

  • Increased heart rate
  • High blood pressure
  • Cardiac arrest
  • Aortic stiffening
  • Heart ventricle wall thickening
  • Heart failure

Keep in mind that drugs of abuse can cause fatality. To avoid this unwanted event, it is highly advised to strictly follow the instructions of a medical doctor. Never self-medicate and do not overdose on the OTC and prescription medications.

A desperate addict woman.

Addictive Drugs Effects on the Liver

It is in the liver where most substances are metabolized. Thus, the abuse of substances may potentially produce long-term and permanent side effects, including liver damage.

Some of the Most Common Liver-related Injuries Drugs of Abuse Can Cause Include:

  • Cirrhosis
  • Hepatitis
  • Liver failure

Based on the study of researchers from China, substance abuse can cause patients to undergo a liver transplant. Although this surgery is possible despite being expensive, the patient’s life expectancy after surgery is only around 5 years.

Drugs Abuse and Effects on the Lungs

The most common effect of the most addictive drugs to the lungs is shortness of breath and take note that both the substances administered via inhalation and orally can produce this adverse reaction.

Other Effects of Drug Abuse on the Lungs Include:

  • Wheezing
  • Crackling in the lungs
  • Pleurisy
  • Pulmonary fibrosis

These lung conditions may occur when the lungs are scarred and inflamed. Some may be due to allergic reactions to the chemicals and this could lead to respiratory depression. For patients taking any medication, once the difficulty of breathing is experienced, seek medical care as soon as possible.

Effects Of Addictive Drugs On The Kidneys

Most substances are excreted via the kidneys. Thus, patients with kidney disorders may find it difficult for the drugs to be removed from their systems on time. Furthermore, people who abuse these substances increase the risk of kidney damage.

Some of the Kidney Injuries Addictive Drugs Can Cause Include:

  • Irreversible renal failure
  • Chronic kidney disease
  • Kidney cancer
  • Nephrolithiasis

Consistent with the research published in the BMC Nephrology, illicit drug use and overdose promote poor renal outcomes. Thus, to prevent these disorders, renal treatment should be started as soon as possible.

Drugs Abuse Effects on the Sexual Function and Fertility

Substance abuse affects the reproductive system. Based on the research of healthcare professionals from Ireland, selective serotonin reuptake inhibitors or SSRIs are the medications that highly affect the sexual function and fertility (73% prevalence rate) of the users.

Some of These Effects Include:

  • Decreased libido
  • Delayed orgasm
  • Erectile dysfunction
  • Delayed ejaculation

People who do take addictive drugs may experience priapism. This condition is a prolonged erection of the penis that also comes with pain. If patients experience ischemic priapism, emergency assistance is needed.

Statistics on the Most Addictive Drugs Use

How many people in the United States abuse the most addictive drugs? Based on the data provided by the National Center for Drug Abuse Statistics, 19.4% of people in the United States have used illicit substances at least once.

In This Section, Information About the Most Dangerous Drugs, Along With the Prevalence Rate of Their Use Will Be Discussed.

  • Opioids are one of the most addictive drugs and over 10 million people in the United States misuse these substances. They account for 72% of national drug overdoses and 50,000 people die from opioid overdose each year.
  • Marijuana is a mind-altering chemical that is considered one of the most dangerous drugs. 78 million people in the United States have used this substance at least once in their life. Currently, 16.9% of Americans still use this substance.
  • Fentanyl belongs to the Schedule II substances. This means that this substance is highly addictive, and in just a dose of 0.07 ounces, death could occur. In 2020, there were around 42,700 fentanyl overdose deaths.
  • Cocaine produces addictive effects and in the United States, even 12-year-olds abuse this substance. In 2020, it was reported that around 5.2 million people used cocaine at the national level and 19,447 people died due to cocaine overdose.

How Do People Abuse Drugs?

There are different ways to administer over-the-counter and prescription medications because these substances come in different dosage forms. Furthermore, a medical doctor will decide what form will be used by a patient. However, abusers of the most addictive drugs find other ways to administer the medications into their system.

Some of These Ways Include:

  • Smoking is a popular way to take addictive drugs. It can cause a lot of health problems, such as lung infections and mouth cancer. It’s not only marijuana or tobacco that one can smoke. Individuals can also do it with heroin and crack, and more. Another form of smoking is inhaling (opium, for example). They can be even more than dangerous as the smoke goes directly into the lungs of the user and causes damage to the body.
  • Injecting or shooting drugs via intravenous, intramuscular, or subcutaneous is also very popular. The reason why many users abuse substances this way is because one can feel the effect of the drug only seconds after intake. Due to the quick result, a lot of people become addicts to their drugs of choice. Whether injecting directly into the skin, the veins, or the muscles, injecting substances is one of the most dangerous ways to take addictive drugs. It can lead to arterial damages, infections, blood clots, and many more health problems. Also, used needles put the user at high risk for HIV and hepatitis.
  • Snorting drugs is also desirable to drug users. Heroin, cocaine, tobacco, and many other substances. Users can feel the effect up to 15 minutes after intake. Snorting can damage the nostrils and the nasal cavity. Also, like shooting and exchanging used needles, using one note by more than one, for instance, can lead to diseases, such as hepatitis and HIV.
  • Taking drugs orally in the form of pills, etc., is another famous route of administration for addictive drugs. Users can swallow alcohol, LSD, mushrooms, and much more. Swallowing is safer than any other way of taking drugs because the drugs slowly go through the stomach, and also the human body has the great ability to clear itself. A person can vomit in case something is too much.
  • Another way of administration is through the rectum, which is dangerous as this area of the human body is very sensitive. Although not very popular, there are many cases of taking addictive drugs like ecstasy this way. When it comes to prescription drugs, however, rectal administration is useful for patients who cannot swallow due to a health condition.
  • Users can also apply drugs to the skin. Nicotine and Fentanyl patches are an example.

No matter what way of administration people choose, drugs affect their central nervous system and this can lead to tolerance and addiction. Thus, strictly complying with the instructions of a medical doctor can help patients avoid unwanted health events.

Group therapy for addicts with drug abuse problems.

Warning Signs and Symptoms of Drug Abuse and Addiction

The best way to spot a patient with addiction and substance abuse disorder is by observing their physical and psychological behaviors. To learn more about these signs and symptoms, take a look at the information below:

Physical Signs of Addiction to the Drugs of Abuse

  • Inadequate hygiene and lack of desire to care to self
  • Decreased libido
  • Changes in exercise habits
  • Frequent flu-like symptoms
  • Weight loss

Drugs of Abuse Psychological Signs of Addiction

  • Having uncontrollable cravings and dietary habit changes
  • Isolation from family and friends
  • Changing friends, hiding new friends
  • Personal relationships and sexual life problems
  • Mood swinging
  • Sleeping at unreasonable times
  • Having problems at school, university, or work
  • Having financial difficulties and asking for money frequently
  • Drowsiness
  • Getting in trouble with the law

Noticing a few of these signs may not always mean the presence of an addiction to narcotic substances, but this may be a signal to have a conversation with that person, consult a medical specialist, and enroll in rehab services.

Who Is Most at Risk of Taking Drugs of Abuse?

According to the Centers for Disease Control and Prevention, the youth are most at risk of substance abuse. However, other age groups are vulnerable as well and some factors increase this risk. Some of these include:

  • Those with a family history of substance abuse disorder
  • Favorable parental attitudes towards the behavior
  • Youth with poor parental monitoring
  • Youth with parental substance use
  • Family rejection of sexual orientation or gender identity
  • Association with delinquent or substance-using peers
  • Lack of school connectedness
  • Low academic achievement
  • Childhood sexual abuse
  • Those with mental health issues

As seen from the list, family guidance and involvement can prevent substance abuse disorder. However, some people may find it hard to talk about substance abuse-related topics with other people. Fortunately, resources such as rehabilitation centers can help patients discuss these topics privately.

Drug Addiction Treatment: How to Cope with Substance Abuse?

It is possible to get drug addiction treatment in rehab centers regardless of which state one lives in. One great thing about these centers is that even teens can enroll. Rehab clients are offered a wide variety of drug addiction treatment methods to choose from.

Some of These Include the Following:

  • 12-Step Program – This program is mainly for those with alcohol use disorder. But, this can also be used for those patients with drug addiction. made to help patients become healthy and productive members of society by promoting their wisdom. Together with a sober living companion, successful recovery can be achieved.
  • Addiction Treatment During Covid-19 – Many establishments are closed due to the pandemic to prevent the spread of the virus. Fortunately, patients with substance abuse disorder can consider online therapy through this program. Aside from this, there are NA online meetings for additional support.
  • Sober living homes – This program is for those who have already finished their rehabilitation time. This is considered as additional support to prevent relapse and make abstinence easier and smoother.

Keep in mind that workers in these institutions are professionals. There are different specialists in these centers and all can help patients prevent drug relapse. Even at this time of the pandemic, patients will get the assurance that they will recover safely.

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Page Sources

  1. Budzak, L. M., Yasin, W., & Mulhall, J. (2019). Raising more than moods: escitalopram-associated priapism. Federal Practitioner, 36(2), 94.
  2. Drug Schedules 1–5. (2021, August 12). Overdose Prevention. https://www.in.gov/health/overdose-prevention/general-information/drug-schedules-1-5/
  3. Drug Scheduling. (2020). DEA. https://www.dea.gov/drug-information/drug-scheduling
  4. FastStats. (2019). Illegal Drug Use. https://www.cdc.gov/nchs/fastats/drug-use-illicit.htm
  5. Fu, P. P., Xia, Q., Guo, L., Yu, H., & Chan, P. C. (2008). Toxicity of kava kava. Journal of Environmental Science and Health Part C, 26(1), 89-112.
  6. High Risk Substance Use in Youth | Adolescent and School Health | CDC. (2020). CDC. https://www.cdc.gov/healthyyouth/substance-use/index.htm
  7. Higgins, A., Nash, M., & Lynch, A. M. (2010). Antidepressant-associated sexual dysfunction: impact, effects, and treatment. Drug, healthcare and patient safety, 2, 141.
  8. Kosten, T. R., & George, T. P. (2002). The neurobiology of opioid dependence: implications for treatment. Science & practice perspectives, 1(1), 13.
  9. Mansoor, K., Kheetan, M., Shahnawaz, S., Shapiro, A. P., Patton-Tackett, E., Dial, L., ... & Khitan, Z. J. (2017). Systematic review of nephrotoxicity of drugs of abuse, 2005–2016. BMC nephrology, 18(1), 1-15.
  10. Mintz, J., O'hare, K., O'brien, C. P., & Goldschmid, J. (1974). Sexual problems of heroin addicts. Archives of General Psychiatry, 31(5), 700-703.
  11. Morse, B. L., Vijay, N., & Morris, M. E. (2012). γ-Hydroxybutyrate (GHB)-induced respiratory depression: combined receptor-transporter inhibition therapy for treatment in GHB overdose. Molecular pharmacology, 82(2), 226-235.
  12. Preuss, C., Kalava, A., & King, K. (2021). Prescription of controlled substances: benefits and risks. StatPearls.
  13. Romolo, F. S., Fiore, P. A., Bottoni, E., Cappelletti, S., Aromatario, M., & Ciallella, C. (2016). Mephedrone and Mephedrone-Based Cocktails: Market, Analysis, Mechanisms of Action, and Toxicity. In Neuropathology of Drug Addictions and Substance Misuse (pp. 40-49). Academic Press.
  14. Thomas, A., Nallur, D. G., Jones, N., & Deslandes, P. N. (2009). Diphenhydramine abuse and detoxification: a brief review and case report. Journal of Psychopharmacology, 23(1), 101-105.
  15. van Hoogdalem, E. J., de Boer, A. G., & Breimer, D. D. (1991). Pharmacokinetics of rectal drug administration, part I. Clinical pharmacokinetics, 21(1), 11-26.
  16. Vorobjov, S., Uusküla, A., Des Jarlais, D. C., Abel-Ollo, K., Talu, A., & Rüütel, K. (2012). Multiple routes of drug administration and HIV risk among injecting drug users. Journal of substance abuse treatment, 42(4), 413-420.

Published on: September 25th, 2015

Updated on: February 4th, 2022

About Author

Decyry Jhoy Serrano, RPh

In 2017, Decyry Jhoy Serrano completed the postgraduate course Drug Menace at St. Luke’s Medical Center in Manila, Philippines. In 2019, she volunteered in the local government’s Narcotics Anonymous and Anti-Drug Abuse programs. She is a speaker and an advocate of anti-drug addiction campaigns. As a remembrance for her late father, Decyry dedicates her time writing the proper use of medications as well as the dangers of drug addiction to educate the people, especially the youth.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.