What Is a Substance?

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What Is a Substance?


Substances refer to illegal drugs, prescription or over-the-counter drugs, and alcohol. Caffeine, nicotine, anabolic steroids, and synthetic drugs are also considered substances. While not all substances are harmful when consumed in moderation—caffeine or prescription medications, for instance—problems can occur when they are abused.

Substance use disorders are on the rise and account for hundreds of billions of dollars in repercussions.

This article discusses the types of substances, the impact of substance abuse, and how to get help if you have a substance use disorder.

Types of Substances

Here are the most commonly abused substances and their impacts on the individual and societal levels. 

Illegal Drugs

Illegal drug use is a prevalent form of substance abuse. According to the National Institute on Drug Abuse, these substances are addictive because they involve changes to the brain circuits involved in stress, reward, and self-control.

While people may turn to them for mood alterations, these drugs can impair judgment, delay reaction times, and distort perceptions, which can put the user in danger. 

Consequences of illegal drug abuse include cardiovascular disease, hepatitis B and C, mental disorders , and cancer.

Here are the most commonly abused illegal drugs in the U.S:

Prescription and Over-the-Counter Drugs

Abuse of prescription drugs occurs when medications are taken at a dose or in a manner other than prescribed; taking another’s prescription, even for a valid concern such as pain; and taking a medication to get high.

Commonly abused drugs are clumped into three categories:

Prescription drug misuse continues to be an ongoing concern. The National Institute on Drug Abuse reports an increase in opioid overdose-related deaths from 3,442 in 1999 to 16,416 between 2019 and 2020.

It’s important to note that over-the-counter (OTC) medications are also likely to be abused. Cough medicines, analgesics (used for pain management), and antihistamines are among the most frequent types of OTC medications that are misused. 


Today’s culture has perpetuated binge drinking, which is especially common among young people. Like illegal and prescription drugs, alcohol can become addictive when individuals lose control over their consumption, drink compulsively, and feel negative emotions in its absence. 

According to the National Institute on Alcohol Abuse and Alcoholism, alcohol abuse can be detrimental to one’s personal health and social life by leading to relationship challenges, motor vehicle accidents, homicide, liver diseases, and suicide. 

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.

For more mental health resources, see our National Helpline Database.


Coffee is the most commonly used drug in the world. Though it is an everyday ritual for many adults, too much can lead to adverse effects. 

Mild unpleasant side effects of caffeine include anxiety, GI discomfort, increased urination, agitation, and insomnia. On the more severe end, individuals may experience hallucinations, psychosis, and cardiac arrhythmias. Like many drugs, caffeine can lead to withdrawal symptoms if consumption is stopped abruptly.


Nicotine is a highly addictive substance found in tobacco products such as cigarettes, cigars, hookah, and most e-cigarettes. According to the 2020 National Survey of Drug Use and Health (NSDUH), 23.6 million people aged 12 and older reported nicotine dependence in the past 30 days.

Chemicals present in tobacco make their use dangerous, and in many cases, deadly. Prolonged use of these nicotine-containing products can lead to fatal respiratory issues such as chronic obstructive pulmonary disease (COPD) and lung cancer.

Anabolic Steroids

Anabolic steroids are synthetic versions of testosterone, the male sex hormone. Athletes and bodybuilders often turn to them to enhance performance and increase muscle mass. Like other substances, anabolic steroids can impair judgment and alter mood and may lead to blood clots, kidney failure, and cardiovascular problems when chronically misused.

Synthetic Drugs

So-called “designer drugs” have been popular since the 1980s and 1990s, when they arose in the midst of “rave” culture.

These substances have the potential to be abused and include:

Societal Impact of Substance Abuse

Substance use disorders (SUDs) are on the rise. They can often co-occur with other mental health conditions.

In 2019, 20.4 million people aged 12 or older (or 7.4% of this population) had a SUD in the past year, including 14.5 million who had an alcohol use disorder and 8.3 million who had an illicit drug use disorder.

There are several risk factors for developing SUDs, often stemming from childhood. These include poverty, lack of parental supervision, and drug availability through peer groups. However, protective factors such as community support and parental monitoring can mitigate these risks. 

Long-term consequences of substance abuse disorders include irreversible damage to the brain and to the body. In addition to chronic illnesses, cognitive and emotional challenges may persist and negatively impact a person’s quality of life. An individual’s relationships, career, and ability to partake in society can also be affected. 

Substance abuse poses a tremendous cost to society in terms of crime, healthcare, and losses in productivity—$740 billion according to The National Institute on Drug Abuse. Beyond these matters, there are additional repercussions such as domestic violence, effects on unborn babies, and the spread of hepatitis C and HIV/AIDS. 

A Word From Verywell

According to the National Institutes of Health, 10% of U.S. adults will have a drug use disorder in their lifetime. It’s essential to seek help for SUDs to avoid long-term social, emotional, and physical effects. Your doctor can refer you to an appropriate treatment program or specialist to ensure that you receive adequate care.

14 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute on Drug Abuse. Costs of Substance Abuse.

  2. National Institute on Drug Abuse. Drug Misuse and Addiction.

  3. National Institute on Drug Abuse. Addiction and Health.

  4. National Institute on Drug Abuse. Misuse of Prescription Drugs Research Report.

  5. Sansgiry S, Bhansali A, Bapat S, Xu Q. Abuse of over-the-counter medicine: a pharmacist’s perspective. Integr Pharm Res Pract. 2017;6:1-6. doi: 10.2147/IPRP.S103494

  6. National Institute on Alcohol Abuse and Alcoholism. The Cycle of Alcohol Addiction.

  7. Meredith S, Juliano L, Hughes J, Griffiths R. Caffeine Use Disorder: A Comprehensive Review and Research Agenda. Journal of Caffeine Research. 2013;3(3). doi:https://doi.org/10.1089/jcr.2013.0016

  8. National Library of Medicine. Caffeine.

  9. Substance Abuse and Mental Health Services Administration. 2020 National Survey of Drug Use and Health (NSDUH) Releases.

  10. U.S. Food and Drug Administration. Nicotine Is Why Tobacco Products Are Addictive.

  11. National Institute on Drug Abuse. Anabolic Steroids DrugFacts.

  12. Substance Abuse and Mental Health Services Administration. Key Substance Use and Mental Health Indicators in the United States: Results from the 2019 National Survey on Drug Use and Health.

  13. National Institute on Drug Abuse. What are risk factors and protective factors?.

  14. National Institutes of Health. 10 percent of US adults have drug use disorder at some point in their lives.

By Brina Patel
Brina Patel is a freelance writer from Sacramento, California. Prior to writing full-time, she worked as an applied behavior analysis therapist for children on the autism spectrum. She leverages her own experiences researching emotions, as well as her personal challenges with chronic illness and anxiety, in her storytelling, with the hope of inspiring others to take better charge of their overall wellness and understand themselves on a deeper level.