Addiction to drugs or alcohol manifests as a compulsive drive to take a drug or consume alcohol despite harmful consequences. The American Society of Addiction Medicine further defines addiction as “a treatable, chronic medical disease involving complex interactions among brain circuits, genetics, the environment, and an individual’s life experiences.”1
Legal drugs (e.g., alcohol, nicotine, marijuana—in some states) and illegal drugs (e.g., cocaine, meth, heroin, etc.), as well as medications (e.g., opioid painkillers, stimulants, tranquilizers and sedatives) are used and abused for various reasons. Some common reasons for drug use include improving performance or to relieve pain, others may be used to alter one’s mental state, and yet others may be used to self-medicate—consciously or subconsciously—a mental disorder.2
Initial use of a substance may be voluntary and recreational, experimental, a result of social pressure or used at the advice of a physician. Once addiction develops, however, behavioral control is impaired, and afflicted individuals suffer structural and functional disruptions in the brain.2
Drugs and substances of abuse affect the dopaminergic circuits that help the brain predict reward and modify motivation. Explained simplistically: drugs affect dopamine, which regulates the body’s pleasure response and reinforces or modifies behavior accordingly, resulting in a person feeling euphoric, or pain-free, or “high.”2-4
Alcohol and Tobacco/Nicotine
Alcohol, which is found in beer, wine and liquor, is the most widely used drug in the U.S. and is commonly used to socialize, celebrate, and relax. According to the 2018 National Survey on Drug Use and Health (NSDUH), 55.9% of people ages 18 or older reported that they consumed alcohol in the past month.5
The effects of alcohol affect individual’s differently, depending on several factors: how much you drink, how often you drink, your age, your health status, and your family history.6
With regular and heavy alcohol consumption, the body can build up a tolerance to alcohol, meaning that the body has developed a dependence on the drug and a person will experience unpleasant and potentially dangerous withdrawal symptoms upon quitting.2
An individual who has developed a tolerance and experiences alcohol withdrawal has an alcohol use disorder (AUD), as defined by the diagnostic criteria laid out in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).7 However, an individual doesn’t have to have built up a tolerance to alcohol or experienced withdrawal to be diagnosed with an AUD.7 The 2018 NSDUH indicates that 5.8% of people ages 18 or older meet the criteria for having an AUD, with only 0.9% receiving treatment.5
Read more on detecting the signs of alcoholism in our Alcohol Treatment Guide.
In 2018, 28.6% of those 18 years and older used tobacco products, which includes cigarettes, smokeless tobacco, cigars, and pipe tobacco.5 These products contain dried and fermented leaves from the tobacco plant, which contains nicotine, a chemical that can lead to addiction.8
Nicotine makes it difficult to quit smoking tobacco, which contains other potentially harmful chemicals or are created by burning it.8 Use of tobacco products increase a person’s risk of developing lung disease, cardiovascular disease, stroke or cancer.9 Resources to help individuals to quit smoking are available at Smokefree.gov, a website from the U.S. National Institute of Health.
Heroin and Prescription Opioids
Heroin is an illegal drug that was originally synthesized from morphine, a medication that acts on opioid receptors in the brain and nervous system to reduce the intensity of pain.10 Prescription opioid medications are used to treat acute pain and include hydrocodone (e.g., Vicodin), oxycodone (e.g., OxyContin, Percocet), oxymorphone (e.g., Opana), codeine, fentanyl, and others.9,10
In 2018, 0.3% of persons aged 18 or older used heroin in the past year; however, 3.7% reported misusing prescription pain relievers.5
In addition to short-term pain relief and drowsiness, opioids activate the brain’s reward regions and produce to a euphoria—or high—particularly when they are taken at high doses or when injected directly into the bloodstream or snorted.10
Opioids have been the most common treatment for chronic pain since the late 1990s, but their safety has been questioned over the last several years, as the risk of developing a tolerance and a substance use disorder is high—even in patients who are prescribed the medication and use it as directed by a physician.10
Opioid overdoses are also a significant danger.9,10 An overdose can lead to dangerous slowing of heart rate and breathing.9 Opioids were involved in 47,600 overdose deaths in 2017 (67.8% of all drug overdose deaths).11
Prescription CNS Depressants
CNS depressants are prescription medications that slow brain activity and cause a person to feel relaxed. They are useful for treating anxiety and sleep problems.12 Common types of CNS depressants are barbiturates, benzodiazepines (e.g., Xanax, Valium, Ativan) and sleep medications like eszopiclone (e.g., Lunesta), zaleplon (e.g., Sonata), and zolpidem (e.g., Ambien).12
In 2018, 2.4% of persons aged 18 or older misused prescription CNS depressants.5
The body becomes accustomed to CNS depressants fairly quickly, and long-term use usually requires larger doses to achieve the same effect.10 Withdrawal from long-term or high doses of CNS depressants can result in seizures or other harmful consequences.10
CNS depressants are dangerous when combined with alcohol, as they amplify the depressant effects of the drug and further slow heart rate and breathing, which can lead to death.10
Stimulants increase the activity in the brain by enhancing the effects of dopamine as well as another neurotransmitter—norepinephrine, which affects blood vessels, blood pressure and heart rate.10,13 Stimulants make a person feel more alert and energetic.13
Prescription stimulants include amphetamine-containing drugs, such as Dexedrine and Adderall, as well as Ritalin and Concerta.13 They are typically used to treat attention-deficit hyperactivity disorder (ADHD) and reduce episodes of uncontrollable sleep (i.e., narcolepsy).5,13
Illicit stimulants include cocaine, crack cocaine, methamphetamine and crystal methamphetamine and produce similar effects.
In 2018, 1.9% of persons aged 18 or older misused prescription stimulants in the past year and 0.7% used methamphetamine in the past year.5
Prescription stimulants are often misused by high school and college students who use them as a “study drug” to enhance cognitive performance and will help them to do better in school.14
Misuse and long-term use of stimulants can lead to heart problems, aggressive behavior and anxiety.9,12 High doses of stimulants can cause dangerously high body temperature and irregular heartbeat and lead to heart disease and seizures.9,12
Marijuana is the most commonly used illicit drug in the country, according to the National Institute on Drug Abuse.15 In the 2018 NSDUH, 34.8% of people used marijuana in the past year.5
A trend toward legalization of marijuana in individual states means that the drug is more widely and easily available. Also, levels of concentration of THC, the active ingredient responsible for the drug’s intoxicating “high,” increased threefold from 1995 to 2014.16
In addition to producing marijuana’s euphoric high, THC is also responsible for some of the undesirable side effects of marijuana: loss of balance, impaired coordination, altered senses, anxiety, paranoia, and sometimes even psychosis. Regular use of marijuana has also been associated with cannabinoid hyperemesis syndrome, a condition of uncontrollable cyclic vomiting over a 24-48-hour period.17
Frequent use of marijuana can lead to dependence, especially at higher doses, and quitting the drug may bring on unpleasant withdrawal symptoms.18
Other Types of Drugs
Other illicit drugs that are sometimes abused include hallucinogens and dissociative drugs, such as LSD, as well as club drugs, such as Molly and Ecstasy.
Getting Help for Addiction
No matter the type of drug, it’s possible to recover from addiction. By seeking out a treatment center with high-quality medical care and the latest treatment strategies, individuals who are struggling with a substance use disorder can successfully recover.19
Evidence-based drug and alcohol addiction treatment can help individuals learn to manage cravings and triggers, create social support networks, and get the resources and skills needed to cease substance use, avoid relapse, and maintain long-term recovery.
- American Society of Addiction Medicine. (2019). Definition of Addiction.
- Miller, S. C., Fiellin, D. A., Rosenthal, R. N., & Saitz, R. (2019). The ASAM Principles of Addiction Medicine, Sixth Edition. Philadelphia: Wolters Kluwer.
- National Institute on Drug Abuse. (2018). Drugs, Brains, and Behavior: The Science of Addiction. Drug Misuse and Addiction.
- National Institute on Drug Abuse. (2018). Drugs, Brains, and Behavior: The Science of Addiction. Drugs and the Brain.
- Center for Behavioral Health Statistics and Quality. (2019). Results from the 2018 National Survey on Drug Use and Health: Detailed Tables.Substance Abuse and Mental Health Services Administration, Rockville, MD.
- National Institute on Drug Abuse. (2019). Alcohol.
- Diagnostic and statistical manual of mental disorders: DSM-5. (5th ed.). (2013). Washington, D.C.: American Psychiatric Association.
- National Institute on Drug Abuse. (2019). Tobacco/Nicotine and Vaping.
- National Institute on Drug Abuse. (2012). Commonly Abused Drugs.
- National Institute on Drug Abuse. (2018). Misuse of Prescription Drugs. What classes of prescription drugs are commonly misused?
- Centers for Disease Control and Prevention. (2019). Drug Overdose Deaths.
- National Institute on Drug Abuse. (2017). Commonly Abused Drugs: Prescriptions and OTCs.
- National Institute on Drug Abuse. (2018). Prescription Stimulants.
- Lakhan, S. E., & Kirchgessner, A. (2012). Prescription stimulants in individuals with and without attention deficit hyperactivity disorder: Misuse, cognitive impact, and adverse effects target=”_blank” rel=”noopener”. Brain and Behavior, 2(5), 661–677.
- National Institute on Drug Abuse. (2019). Drug Facts: Marijuana.
- Elsohly, M. A., Mehmedic, Z., Foster, S. (2016). Changes in Cannabis Potency Over the Last 2 Decades (1995-2014): Analysis of Current Data in the United States. Biological Psychiatry, 79(7), 613-619.
- Galli, J. A., Sawaya, R. A., & Friedenberg, F. K. (2011). Cannabinoid hyperemesis syndrome. Current Drug Abuse Reviews, 4(4), 241–249.
- National Institute on Drug Abuse. (2019). Marijuana Research Report: Is marijuana addictive?
- National Institute on Drug Abuse. (2018). Principles of Drug Addiction Treatment: A Research-Based Guide (Third Edition): Evidence-Based Approaches to Drug Addiction Treatment.