Drug Addiction & Abuse

One out of every ten American adults abused an illicit drug in the month leading up to the 2014 National Survey on Drug Use and Health (NSDUH), which translates to over 25 million people.1 Drug abuse is a leading cause of mortality, as the National Institute on Drug Abuse (NIDA) publishes that over 50,000 people in the United States died from a drug overdose in 2015.2 Approximately 2.5 million Americans sought emergency department (ED) treatment for issues related to illicit drug abuse in 2011, the Drug Abuse Warning Network (DAWN) reports.3

Drug abuse is not only detrimental to an addicted person‘s physical wellbeing; it can also have a range of emotional, social, financial, and behavioral ramifications, not the least of which is drug addiction. Of course, not everyone who abuses drugs suffers from addiction; however, the NSDUH reports that over 7 million people battled addiction involving illicit drugs in 2014.

How Does Drug Abuse Become Addiction?

Addiction is a complex and individual disease. There are many factors that contribute to its onset, such as:

  • Genetics and family history of addiction: The journal Clinical Pharmacology & Therapeutics reports a heritability rate of about 50 percent for addiction.4
  • Environmental aspects: High levels of stress, exposure to trauma, and low levels of support in the home environment all influence the formation of addiction.
  • Biological factors: This includes things like metabolism, gender, and ethnicity.
  • Presence of co-occurring disorders: The Substance Abuse and Mental Health Services Administration (SAMHSA) reports that about 8 million people suffered from both a mental health disorder and an addiction simultaneously in 2014.5 The presence of each disorder can compound, exacerbate, and contribute to symptoms of the other disorder.
  • Type of drug abused: Some drugs are more addictive than others.
  • Method of drug abuse: Injecting, snorting, and smoking drugs sends them directly into the bloodstream and can lead to drug dependence and addiction more quickly than swallowing them can.
  • Polydrug abuse: Abusing more than one drug at a time can increase the rate of dependence and heighten all potential risks, including addiction.

How Do Different Drugs Affect the Brain?

Mind-altering drugs interact with naturally occurring chemicals in the brain that are used to send messages throughout the central nervous system, brain, and body. Central nervous system depressant drugs, such as opioids (heroin and prescription narcotic painkillers) and benzodiazepines (sedatives and tranquilizers), increase levels of GABA (gamma-aminobutyric acid), which acts like a sedative in and of itself, leaving individuals feeling relaxed and loose.

Stimulant drugs like cocaine, methamphetamine, and prescription stimulants (ADHD medication) have the opposite effect and increase energy and arousal levels. Hallucinogenic drugs (PCP, LSD, MDMA, and magic mushrooms) alter the way people view themselves and the world around them. Marijuana is a drug that has both relaxing and hallucinogenic properties. Developed for use in anesthesia, ketamine has the potential to provide pain relief, amnesia, and sedation.

All of these drugs disrupt natural brain chemistry. Most act on the brain’s natural reward system and interfere with the normal production, transmission, and reabsorption of dopamine. Dopamine is related to how people perceive pleasure, and when levels are high in the brain, a person feels euphoric, or even “high.” As levels drop, so do moods. Chronic artificial disruption of dopamine levels in the brain as a result of substance use can cause the brain to stop making and moving dopamine around as it normally would.

How Does Drug Dependence Develop?

Drug dependence can develop, and a person may then rely on the drug in order to feel balanced or happy. Cravings and withdrawal symptoms can occur when the drug wears off, and levels of dopamine (and other chemical messengers) drop or are significantly altered. Withdrawal symptoms can include:

  • Malaise. 
  • Depression. 
  • Irritability.
  • Insomnia. 
  • Mental confusion. 
  • Trouble concentrating. 
  • Hallucinations.
  • Agitation.
  • Tremors. 
  • Flu-like symptoms. 
  • Irregular heart rate and blood pressure.
  • Fever. 
  • Chills.
  • Delirium. 
  • Potentially life-threatening seizures.

Physical drug dependence is not the same thing as addiction; however, it is often one of the signs of addiction. Other signifiers include drug tolerance (needing to take more drugs each time to feel their effects), and using drugs more often and for longer than was intended initially. A significant amount of a person’s time is taken up with using drugs and recovering from them in rehab when addiction is present.

How Is Drug Addiction Defined?

The American Society of Addiction Medicine (ASAM) defines addiction as a brain disease that is chronic and relapsing.6 It includes compulsive drug use and an inability to abstain from doing so. A person battling addiction may make many attempts to stop using drugs and be unsuccessful. Drug use will interfere with everyday life, and family, school, and work obligations will likely be inconsistently attended to. Relationships, job status, home life, and school grades can all suffer as a result. Things that were once important, like social activities, may no longer be a priority.

Someone battling drug addiction continues to use drugs in situations that are potentially dangerous. They will keep using them despite knowing that illicit drugs are causing negative physical, emotional, behavioral, and social issues. Repeated and regular substance abuse can lead to addiction.

What Is the Addictive Potential of Commonly Abused Drugs?

Not all drugs have the same addictive potential. Some can lead to addiction more quickly than others; some create significant physical dependence, which makes it hard to stop using them; and others cause psychological dependence.

Addiction is a behavioral disease that encompasses both emotional and physical aspects. It is also highly individual, and not everyone will become addicted at the same rates. Some of the most commonly abused drugs in the United States are outlined below with their addictive potential.


According to NIDA, marijuana is the most commonly abused illicit drug in America.7 The NSDUH reports that in 2014 there were over 22 million current users of marijuana in the United States (current use is defined as past-month use). The NSDUH further publishes that over 4 million Americans battled addiction involving marijuana.

Everyone who abuses marijuana does not suffer from addiction. With the legalization of the drug across many states, there has been much debate over the potential addictive nature of marijuana. NIDA warns that marijuana can lead to addiction with regular and prolonged use, as individuals who abuse it on a chronic basis are likely to suffer withdrawal symptoms and cravings, and have difficulty controlling their use.8 Around 30 percent of people who use marijuana will suffer from addiction, and those who use the drug prior to turning 18 are 4-7 times more likely to struggle with addiction than those who begin using the drug as adults.8

Opioid Drugs

Prescription painkillers like OxyContin (oxycodone) are commonly abused and considered highly addictive. The NSDUH reports that there were over 4 million Americans abusing prescription pain relievers at the time of the 2014 survey. ASAM publishes that around 2 million people in the United States battled addiction to these drugs in 2015.9

Opioid drugs bind to opioid receptors in the brain to block pain perceptions. They also slow down functions of the central nervous system, causing drowsiness and relaxation. Opioids are also euphoria-inducing and produce an intense high that people may be keen to recreate. When opioids are taken long-term, even as directed but especially when misused, they can be very habit-forming. Heroin is an illegal opiate that functions the same way as prescription opioids do. In 2015, over 600,000 people suffered from heroin addiction in the US. ASAM warns that almost a quarter of those who abuse heroin will battle addiction to it at some point.


Prescription sedatives and tranquilizers often used to treat anxiety like Xanax (alprazolam), Valium (diazepam), and Ativan (lorazepam) serve to enhance the presence of GABA, decreasing stress and tension and promoting sedation. They are often abused for the mellowing and pleasant high they can produce.

Over 2 million American adults abused sedatives or tranquilizers at the time of the 2014 NSDUH. These medications are also habit-forming and can cause drug dependence even with licit medicinal use. Abuse of these drugs increases the risk for adverse reactions and addiction.

Cocaine, Methamphetamine, and Stimulant Drugs

Cocaine is a powerful stimulant that induces extreme euphoria, and as such, it is considered to be very addictive. It boosts energy, increases wakefulness, depresses appetite, and makes people feel good. Around 1.5 million people were currently using cocaine at the time of the 2014 NSDUH, and nearly 1 million battled addiction to the drug. Cocaine interferes with natural levels of dopamine and serotonin, and can leave individuals feeling significantly depressed and lethargic when it wears off. Cravings for cocaine can be intense.

Methamphetamine is another stimulant drug that is also highly addictive, and prescription stimulants like those used to treat ADHD, such as Ritalin (methylphenidate) and Adderall (amphetamine/dextroamphetamine), can also lead to dependence and addiction. Meth is usually manufactured in illicit laboratories as an illegal drug of abuse while prescription stimulants may be diverted and used as “study drugs,” combined with alcohol and used as “party drugs,” or used as appetite suppressants. The NSDUH reports that nearly 1.5 million people in the United States abused methamphetamine and stimulant drugs (not counting cocaine) in 2014. Close to one-third of college students have potentially abused a prescription stimulant at some point, USA Today publishes.10

Hallucinogenic Drugs

Typically not considered to be addictive, hallucinogenic drugs can still have lasting effects on the brain. These drugs like LSD (lysergic acid diethylamide), PCP (phencyclidine), mescaline, ecstasy or MDMA, and “magic” mushrooms (psilocybin) alter the senses and a person’s perceptions during what is commonly called a “trip.” These trips may be pleasant or negative, and depending on the drug taken, they can last up to several hours. Individuals may also experience “flashbacks,” or a re-experiencing of symptoms weeks, months, or even years later. The NSDUH estimates that at the time of the 2014 survey, more than 1 million American adults abused hallucinogenic drugs.


Inhalant drugs are typically found in common household and commercial products, including aerosol sprays, nitrates, cleaning fluids, gasoline, nitrous oxide, paint thinner, glues, and more. These products are not generally highly addictive but can be dangerous to abuse. More than a half-million individuals were abusing inhalants in the month leading up to the 2014 NSDUH.

Where Can You Receive Addiction Treatment?

Drug abuse can be extremely detrimental to a person emotionally, physically, and socially, impacting relationships, finances, employment, and health. There are multiple treatment options available to help a person stop abusing drugs and manage addiction. Programs range from flexible outpatient drug rehab services to the more structured inpatient treatment programs.

Each person will have a different set of circumstances, and treatment should be tailored to suit the individual. A person who struggles with addiction, drug dependence, and/or a co-occurring mental health disorder will likely benefit from an intensive inpatient program that can provide around-the-clock care and supervision, allowing the brain time to heal and healthy habits to be learned and fixed.

What Is Medical Detox for Drug Addiction?

Physical drug dependence often requires medical detox in order to manage withdrawal and cravings while the drug is processed out of the body. Drugs like benzodiazepines and opioids should not be stopped suddenly, and medical detox is the safest recourse. Medications may be useful tools both during detox and into treatment to manage withdrawal symptoms, cravings, and any underlying medical or mental health concerns.

Comprehensive Approach to Drug Addiction Treatment 

NIDA publishes that drug abuse and addiction should be treated in a comprehensive manner and focus on all aspects of the disease.11 Behavioral therapies and counseling are considered to be integral parts of a complete treatment program.

Individuals and loved ones can learn about the disease of addiction through educational programs and acquire new life and communication skills in workshops and during group and individual sessions. Therapy can work through the reasons a person abuses drugs and help them to develop healthy coping mechanisms and tools for avoiding relapse and managing potential triggers. Finally, peer support groups and aftercare programs help to sustain recovery on a long-term basis.

Unsure where to start? Take Our Substance Abuse Self-Assessment

Take our free, 5-minute substance abuse self-assessment below if you think you or someone you love might be struggling with substance abuse. This evaluation consists of 11 yes or no questions that are designed to be used as an informational tool to assess the severity and probability of a substance use disorder. The test is free, confidential, and no personal information is needed to receive the result. Please be aware that this evaluation is not a substitute for advice from a medical doctor.