An Overview on Drug Addiction


One of the potential consequences of substance abuse is addiction.

When a person misuses or abuses a drug, changes can occur in the brain and body that result in the person becoming dependent on the substance to the degree that it is impossible to function or feel good without using it regularly.

This can result in major problems for the individual and for loved ones, causing disruption in all areas of life.

Researchers and addiction experts are continually seeking answers about what addiction is, what causes it, who is most likely to become addicted to drugs, and how to help people who are struggling with addiction. While not all of the answers are known yet, the quest is ongoing, and there is a vast amount of information that has been found. These solid, research-based findings give a broad view of addiction and of ways in which people can work toward recovery from drug addiction.

What Is Addiction?

According to the American Society of Addiction Medicine, addiction is defined as a chronic illness that affects the reward, pleasure, memory, motivation, and connected areas of the brain, related to pursuit of substance use or other behaviors. Drug addiction, then, is this condition as related to use of chemical substances.

Drug addiction is characterized by an inability to stop using the substance of abuse, whether for pleasure or for relief. This compulsive need for the substance results in behavioral, physical, and psychological problems that can interfere with a person’s ability to function. These issues include:

  • Physical impairment when trying to stop using the drug
  • Development or increased severity of psychological disorders, such as depression or anxiety
  • Relationship issues based on continued substance abuse
  • Inability to keep up with responsibilities at work, school, or home
  • Decrease in self-care, including malnutrition and poor hygiene

As stated by the National Institute on Drug Abuse (NIDA), addiction is considered to be a mental health disorder that, like many psychological and physical disorders, has cycles of relapse and recovery. There is no cure for addiction; however, with treatment, the symptoms and cycles of this disorder can be managed throughout a person’s life to mitigate its harmful effects.

What is addiction?

How Addiction Starts

the path to addiction

There are multiple paths to drug addiction, but all are based on one basic behavior: misuse or abuse of substances. This can manifest in a variety of ways, including:

  • Using prescription drugs more often or at higher doses than prescribed
  • Experimenting with highly addictive substances for recreational purposes and pleasure-seeking purposes
  • Using substances to self-medicate for other mental health or physical disorders
  • Involvement with social groups that accept or participate in drug abuse

When addictive substances are used regularly, they can cause physical changes to the brain’s structure and chemical activity that result in the brain coming to depend on the presence of that substance rather than the natural hormones and neurotransmitters that would normally be involved. This leads to both physical and psychological aspects of addiction.

addiction word cloud
However, use of drugs is not the only element that leads to addiction. Some people who use drugs do not begin to abuse them or become addicted to them. Various studies and articles, including one from Current Opinion in Neurobiology, assert that the tendency toward drug abuse and addiction starts with certain susceptibilities that already exist in the brain. A person who already has a tendency toward impulsiveness, for example, is more likely to become addicted than one who is better able to control behavior.

Truthfully, addiction is a complex combination of all these elements, along with other physical, psychological, and social
factors that make each person’s path to addiction and treatment
needs unique.

The Brain’s Reward System

The main center for the addictive response in the brain is the complex reward system that produces pleasurable feelings through production of a neurochemical called dopamine. When a person uses drugs, the production of dopamine can be directly or indirectly affected, associating a pleasure response to use of the drug and a negative response to being without the drug. While this response is still not fully understood, it is generally considered to be the main mechanism behind addiction.

However, the process of addiction is more complex than this. Each type of drug disrupts the normal function of other chemical pathways, resulting in the particular type of “high” produced by that drug. As described by NIDA, other natural chemical pathways affected by substance abuse include:

  • Serotonin: regulates mood and produces feelings of calm
  • Norepinephrine: reduces anxiety levels
  • Endogenous opioids: regulate pain levels and perception
brains reward system
  • Endogenous cannabinoids: control cognition and memory
  • Acetylcholine: increases arousal and mood
  • Glutamate: increases activity in the brain
  • Gamma aminobutyric acid (GABA): slows activity in the brain

Continued interference in these systems through drug use can result in tolerance of the drug, which means that more of the substance is needed to produce the same effect that it provided with initial use. This leads to a physical and psychological need to keep using the substance in order for the person to feel good.

Manifestation of Addiction

events that trigger relapse

As described in an article from Harvard Medical School, the brain’s pleasure response is not the only manifestation of addiction.

The events, feelings, and relationships associated with the addiction can also affect the person’s inability to stop using drugs. These elements of addiction are the triggers that can cause a person to relapse to abuse even after years of abstinence, when the brain’s systems should have returned to normal.

This psychological level of addiction can be extremely difficult to manage, and it is a major reason that addiction is chronic and should be treated throughout a person’s life. Much of this challenge can be attributed to stress and the memories connected to substance abuse. Some of the hormones released during the stress response can cause memories to surface that reignite cravings and result in relapse. Similarly, if a person encounters a situation, person, or feeling associated with previous substance use episodes, the memories can cause cravings to arise.

A research review in Neuron demonstrates that memory and stress are caught up in the neurochemical systems also associated with addiction, which implies that even when the systems themselves return to normal after a period of abstinence, the memories associated with them and feelings of stress can make the person feel that a need for the substance exists nevertheless. This connection of the stress and memory systems to the potential for relapse into substance use creates a need for ongoing sources of stress relief and cognitive-behavioral management to maintain recovery.

Risk Factors for Addiction

As described above, there are certain factors that make it more likely that a person will abuse or become addicted to drugs. According to an article in Osteopathic Family Physician, these risk factors are primarily environmental – that is, external factors or events that affect the person – or internal, including the person’s physical and psychological traits and genetic elements.

External factors:

  • Socioeconomic status
  • Childhood or other trauma, abuse, or neglect
  • High stress at home, work, or school
  • Family or friends who are permissive or accepting about drug use

    Internal factors:

  • Family history of mental illness or substance abuse
  • Prior issues with substance abuse
  • Existing or current mental illness, such as anxiety or depression

People struggling with these factors are more likely to initiate drug use, and they are also more likely to develop addiction to the drug of abuse.

Most Common Drugs of Abuse

There is a wide range of drugs that are commonly abused. These can be grouped under several larger categories based on how they affect the body. The groups include stimulants, depressants and hypnotics, and hallucinogens, as well as other drugs that may combine these elements. According to NIDA, some of the most commonly abused drugs fall into the following categories:

  • Stimulants: These drugs cause increases in brain activity, resulting in higher energy levels, agitation, high heart rate and blood pressure, and euphoria. Examples include cocaine, methamphetamine, and cathinones (bath salts).
  • Depressants: Central nervous system depressants cause relaxation, calmness, slowed breathing, decreased heart rate, and decreased cognitive function. Examples include opioids (prescription painkillers like OxyContin and Vicodin, or illicit heroin), benzodiazepines (anti-anxiety drugs like Valium and Xanax), and a
  • Hallucinogens: These substances can cause a person to see, hear, and feel things that aren’t there, and can bring about a dissociative effect, making the person feel that everything is unreal. Examples include PCP (angel dust), ecstasy, and ketamine.
  • Other: These substances can create feelings that combine various elements of the above, as well as other sensations. Examples include marijuana and cough medicines like dextromethorphan or promethazine-codeine.

Some of these drugs are restricted but legal for medical use, such as prescription opioids and benzodiazepines. Others are illicit, like heroin and cocaine.

Substance Abuse and Addiction by the Numbers

Addiction is a major health and socioeconomic issue in the US. According to the most recent National Survey of Drug Use and Health, about 21.5 million people had a substance abuse disorder; this includes addictions to both drugs and alcohol. Other statistics about substance abuse include:

  • The drug with the highest level of abuse is marijuana, with 22.2 million Americans 12 and over reporting nonmedical marijuana use.
  • Approximately 7 percent of people in the US report nonmedical use of psychotherapeutic drugs, such as prescription painkillers, anti-anxiety medications, and stimulants like those prescribed for attention deficit hyperactivity disorder.

  • About 3.3 percent of all adults have both a substance use disorder and some other form of mental health disorder.

statistics about substance abuse

  • Opioid drug abuse, including abuse of both heroin and prescription painkillers, is at epidemic levels, according to the Centers for Disease Control and Prevention (CDC). Rates of heroin use more than doubled between 2002 and 2013, and 45 percent of those who used heroin were also addicted to prescription painkillers.
  • Hallucinogens are used by approximately 1.2 million people. Specifically, 0.1 percent of people in the US aged 12 and older use LSD, and 0.2 percent use ecstasy.

  • Addressing the issues of drug abuse, including health and economic factors, is estimated to cost Americans about $600 billion each year.

Dangers of Addiction

Addiction to any type of substance presents a variety of health risks and dangers, up to and including death by overdose. According to the CDC, drug poisoning is the leading cause of injury death in the US, and overdose due to drug abuse and addiction contributes significantly to this.

However, there are a number of other dangers and risks of addiction, as described by NIDA, including:

  • Higher risk of diseases, such as cancer, HIV, and hepatitis
  • Heart attacks, respiratory collapse, liver disease, or other organ damage or failure
  • Brain damage that can result in permanent physical and psychological impairment
  • Immediate and future mental and physical damage to offspring of pregnant women who use drugs
  • Injury or death, or harm to others, due to risky or violent behavior

Other areas affected by addiction include personal finances, relationships with family and friends, and work and personal responsibilities. These repercussions can be severe and long-lasting.

dangers of addiction

As with any physical or mental health disorder, these dangers and risks can be mitigated by getting treatment for addiction at a reputable, accredited, and research-based treatment program.

Getting Help

There are a number of options for getting help with drug addiction. These options range from short-term, minimal interventions to a full continuum of care that includes detox, treatment, and aftercare.

As described above, addiction is a chronic disorder requiring continued maintenance of treatment to avoid relapse and achieve long-term recovery. Because of this, minimal interventions tend not to provide the treatments, skills, and motivation needed to continue the recovery process throughout the individual’s life. In fact, research such as a study from JAMA Psychiatry shows that the amount of time a person spends in quality treatment can be an indicator of how long the person can maintain recovery after treatment is over. For this reason, addiction treatment experts recommend a comprehensive program that includes:

  • Medically supported detox
  • Medical support of abstinence during treatment, if needed
  • Behavioral therapies
  • Family or relationship therapy
maintaining recovery
  • Peer support groups, such as 12-Step programs
  • Motivational therapy and other abstinence support programs
  • Aftercare that continues after structured treatment ends

With research-based treatment and determination, a person who is addicted to drugs can achieve and maintain recovery. With comprehensive care and ongoing support, the person can avoid relapse and the physical, psychological, and social issues that come with ongoing addiction.