What Makes Drugs Addictive?

Fruit ferments on the vine. Stimulant and hallucinogenic plants grow in the wild. Substance use, abuse, and addiction predate civilization.

So, what makes a drug addictive? Several factors are involved.

What Is Addiction?

Addiction is a chronic brain disease, not a moral flaw or a lack of willpower.

According to many sources, an addiction to drugs occurs when people feel compelled to continue consuming substances even when they are aware that they are causing harm to their health, hygiene, and social standing. If people try to stop using the substances and they suffer symptoms of physical and mental pain known as withdrawal, they are addicted.

In the broadest sense, many things are addictive, including food and coffee, plus behaviors such as exercise, shopping, and gambling. Drugs such as alcohol and cocaine are physically as well as mentally addictive.

What Substances Are Addictive?

Some of the things that make a drug addictive are things that give it its initial pleasurable effects: its chemistry and how it interacts with the body’s biochemistry.

In a 2007 article in The Lancet, a panel of addiction experts determined that the five most addictive substances on Earth (in order) are:

  • Heroin, an illegal opioid
  • Cocaine, an illegal stimulant
  • Nicotine, the key addictive component of tobacco
  • Barbiturates, central nervous system (CNS) depressant drugs used as sedatives
  • Alcohol

According to the National Institute on Drug Abuse (NIDA), the most commonly used addictive drugs include:

  • Marijuana (cannabis) and THC (tetrahydrocannabinol)
  • Synthetic cannabinoids such as K2 or Spice
  • Prescription opioids (OxyContin, Vicodin, Percocet)
  • Prescription stimulants  (Ritalin, Concerta, Adderall, Dexedrine)
  • Prescription sedatives and tranquilizers  (Ambien, Lunesta, Valium, )
  • Over-the-counter (OTC) medications (dextromethorphan or DXM, a cough suppressant, and loperamide, an antidiarrheal)

What Makes Drugs Addictive?

While some substances may be technically more addictive than others, any drug can become addictive. Nicotine in cigarettes, alcohol, prescription painkillers, and illegal drugs all can be addictive. However, the risk of addiction is based as much or more on individuals and their circumstances, not drugs themselves.

Anyone can become addicted to drugs or alcohol, including nurses, doctors, law enforcement agents (like Spencer Reid on Criminal Minds) or straight A students (see Spencer Hastings on Pretty Little Liars). It could happen the first time you try a drug, as can a fatal overdose. (Even dogs can become addicted to opioids.)

Some of the things that make drugs addictive include:

  • Dopamine. Addiction is not just a matter of lack of willpower. Addiction changes the brain and hijacks the reward system, which affects the release of the neurotransmitter dopamine. That’s how the brain becomes addicted to drugs. This artificially induced dopamine release increases the risk of addiction. Substance use disorder speeds the flow of dopamine and overloads the brain until it becomes less able to produce dopamine on its own.
  • Tolerance. At the same time, the brain develops tolerance to the substance being abused. The brain produces less dopamine in response, so the user requires larger doses to experience the same pleasurable experiences he or she felt before.
  • How people use the substance. Another factor is how the substance is consumed. Some methods speed dopamine delivery, increasing the likelihood that addiction will develop. Swallowing a pill is one of the least risky methods. Some drugs can enter directly threw the nose; for example, snorting coke. Using drugs intravenously or injecting them are considerably more risky practices, as is smoking drugs.
  • Genetics. There is also evidence that some people are genetically predisposed to addiction. This explains why some people can stop at one drink or use a drug recreationally once in a while without compulsively using it. Genetics may account for 50 percent or more of one’s addiction risk.
  • Family history. Aside from the genetic angle, a history of substance use in the family can also increase the risk of substance use. If you see your parents drinking, smoking marijuana, taking prescription opioids, or using stimulants such as cocaine, the odds that you will do likewise are also increased.
  • Post-traumatic stress disorder (PTSD). If you have been physically or mentally abused, injured in an accident, or spent time in a war zone, you may suffer residual effects known as PTSD that may make you more susceptible to addiction.
  • Mental health. Depression, anxiety, or other mental health problems also increase the likelihood of addiction. Often, addiction may occur because people are attempting to self-medicate undiagnosed mental disorders. Using drugs and alcohol may help alleviate the symptoms of mental illness at first, but such use often leads to two problems that both need treatment. This condition is called a dual diagnosis or a co-occurring disorder.

What Is Withdrawal?

Withdrawal doesn’t cause addiction but it may compel people to continue using addictive substances to avoid going through withdrawal.

People may experience the symptoms of withdrawal if they stop using addictive substances. Withdrawal pains can be minor, say a headache, or can be so overwhelming that you resume using substances because you are desperate to end pain and other withdrawal symptoms.

Sometimes, the effects are subtler. Withdrawal may leave you unable to function but not actually in pain. Occasionally, particularly in extreme cases of alcohol and methamphetamine (meth) addiction, sudden and total withdrawal can be fatal. Many will try their luck on their own, by using online recipes; for example, searching cocaine comedown recipe-which can lead to inaccurate and dangerous information because they fail to realize how cocaine can kill you.

The discomfort, pain, and fear of death (real or unreal) may cause continued drug use or relapse.

Any substance or behavior can be psychologically addictive, but the use of certain drugs and other substances make addiction more likely. This is partly due to the chemical makeup of drugs, partly due to drugs’ effects on the pleasure or reward system of the brain, partly based on an individual’s genetic makeup, and partly based on an individual’s history.


  • drugabuse.gov – Cocaine: What Is Cocaine?
  • drugabuse.gov –  Tobacco, Nicotine, and E-Cigarettes: How Does Tobacco Deliver Its Effects?
  • drugabuse.gov – Prescription CNS Depressants: What Are Prescription CNS Depressants?
  • drugabuse.gov – Alcohol
  • drugabuse.gov – Media Guide: Most Commonly Used Addictive Drugs: Marijuana
  • drugabuse.gov – Synthetic Cannabinoids (K2/Spice)
  • drugabuse.gov – Prescription Opioids: What Are Prescription Opioids?
  • drugabuse.gov – Prescription Stimulants: What Are Prescription Stimulants?
  • drugabuse.gov – Prescription CNS Depressants: What Are Prescription CNS Depressants?
  • drugabuse.gov – Over-the-Counter Medicines: What Are Over-the-Counter (OTC) Medicines?
  • teens.drugabuse.gov – Real Teens Ask: Which Drug Is Most Addictive? (Drugs & Health Blog)
  • drugabuse.gov – Drugs, Brains, and Behavior: The Science of Addiction
  • drugabuse.gov – Genetics and Epigenetics of Addiction
  • ptsd.va.gov – PTSD: National Center for PTSD

Medical disclaimer:

Sunshine Behavioral Health strives to help people who are facing substance abuse, addiction, mental health disorders, or a combination of these conditions. It does this by providing compassionate care and evidence-based content that addresses health, treatment, and recovery.

Licensed medical professionals review material we publish on our site. The material is not a substitute for qualified medical diagnoses, treatment, or advice. It should not be used to replace the suggestions of your personal physician or other health care professionals.

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