Reviewed on 1/26/2022

What Is Addiction?

The current model to explain addiction suggests that addiction begins with the basic pleasure and reward circuits in the brain, which involve the chemical dopamine. These reward centers are designed to activate during pleasurable acts such as eating. Whenever ingesting a substance causes these reward circuits to activate, addiction and dependence is possible. However, addictive behaviors that are considered damaging or destructive have characteristics that distinguish them from normal behavior (see common characteristics of destructive addictions. Examples of common destructive addictions are alcohol intoxication, alcoholism, cocaine abuse, drug dependence and abuse, methamphetamine abuse, narcotic abuse, and substance abuse.

People with addictions often cannot quit on their own. Addiction is an illness that requires treatment. Treatment may include counseling, behavioral therapies, self-help groups, and medical treatment. People often assume that those with addictions should be able to quit by simply making up their minds to do so. Addiction is thought to be possible for a wide range of chemical substances. Dependence, most often related to physical symptoms, can occur for a subset of the chemicals that cause addiction. For instance, rarely an individual is prescribed a medication by a doctor for a legitimate reason (such as pain after an injury) and this can lead to physical withdrawal symptoms if this medication is stopped. Rarely, this post-medical treatment drug dependence can lead to drug abuse. People with drug abuse problems are individuals whose brain biochemistry has been altered by alcohol or drugs.

  • The words addiction, drug addiction, alcoholism, and chemical dependency are common terms for abuse of alcohol or drugs.
  • Addiction (or drug abuse) is often confused with dependence.
  • Many drugs can affect the brain. Some of these cause changes in behavior and can result in dependence or abuse.
  • Dependence is the development of withdrawal symptoms after use of a substance is stopped. It can happen with the subset of chemical substances that are psychologically or physically habit-forming. Dependence is characterized by tolerance. Tolerance occurs when the body becomes less responsive to a specific amount of a substance, thereby causing the person to increase the amount of drug intake to achieve the previous effect. Well-defined physiological or psychological symptoms may occur upon withdrawal.

What Causes Addiction?

Addiction or substance abuse is a complex brain disease. A person with an addiction experiences cravings that persist even in the face of extremely negative consequences. During a craving, a person with an addiction misses the habit-forming drug terribly, and often he or she experiences symptoms of withdrawal.

Evidence strongly suggests that genetic susceptibilities and biological traits play a role in addictions; however, the development of an addiction is also shaped by a person's environment (for example, a person with alcoholism cannot become addicted without access to alcohol). The "addictiveness" of a drug is related to how strongly the drug activates the reward circuits in the brain. For instance, when the methamphetamine found on the street is purer (meaning that it stimulates the dopamine reward circuits more), then the number of first-time drug users who become drug abusers is higher.

Addictive substances or behaviors change the reward circuits in the brain. In other words, the brain responds to the addictive substance in the same way that it responds to very pleasurable experiences. This explains, in a general sense, why people with addictions sometimes forsake all other life activities and obligations and even their own health in pursuit of the addictive substance.

What Are Addiction Symptoms and Signs?

According to the Diagnostic and Statistical Manual of Mental Disorders, substance use is considered abusive or addictive if the person has experienced three or more of the following signs during a 12-month period:

  • Tolerance is evident when (1) a need exists for increased amounts of a substance to achieve intoxication or desired effects or (2) the effect of a substance is diminished with continued use of the same amount of the substance.
  • Withdrawal is evident when (1) characteristic, uncomfortable symptoms occur with abstinence from the particular substance or (2) taking the same (or closely related) substance relieves or avoids the withdrawal symptoms.
  • The substance is used in greater quantities or for longer periods than intended.
  • The person has a persistent desire to cut down on use of the substance, or the person's efforts to cut down on use of the substance have failed.
  • Considerable time and effort are spent obtaining or using the substance or recovering from its effects.
  • Important social, employment, and recreational activities are given up or reduced because of an intense preoccupation with substance use.
  • Substance use is continued even though some other persistent physical or psychological problem is likely to have been caused or worsened by the substance (for example, an ulcer made worse by alcohol consumption or emphysema caused by smoking).

Drug abuse can occur with or without tolerance or withdrawal. Tolerance and withdrawal indicate physical dependence. A key issue in evaluating addiction is if a person is unable to stop using the harmful substance (loss of control). Often people who are addicted to a drug do not have insight into their inability to stop drug use and falsely believe they could stop if they "wanted to." This is called denial.

No single event or criterion is indicative of an addictive disorder; drug use becomes addiction (drug abuse) only after a pattern of behavior that takes place over time. In many ways, current definitions of addiction are limited and mostly incorporate behavioral symptoms in the definition.

Common Characteristics of Destructive Addictions

The essence of addiction is drug craving, seeking, and use, in the face of negative health or social consequences. This is the basis for how the Institute of Medicine, the American Psychiatric Association, and the American Medical Association define addiction. Some common characteristics of addictions include the following:

  • The substance or activity that triggers addiction must initially cause feelings of pleasure and changes in emotion or mood.
  • The body develops a physical tolerance to the substance or activity, so people with addictions must take larger and larger amounts of a substance to feel the same effects.
  • Removal of the drug or activity causes painful withdrawal symptoms.
  • More than physical tolerance, an addiction involves physical and psychological dependence separate from the need to avoid the pain of withdrawal.
  • Addiction always causes physiological, chemical, and anatomical changes in the brain along with behavioral changes.
  • Addiction develops after an initial exposure to the addicting substance or activity. That initial exposure must occur for addiction to develop, but the exposure does not always lead to addiction.
  • Addictions lead to repeated behavioral problems, take a lot of time and energy, and are marked by a gradual obsession with the drug or behavior.
  • The cycle of quitting the addictive behavior, going through withdrawal, and relapsing may become self-reinforcing.

Common Characteristics of People with Addictions

  • People with addictions have the opportunity to obtain the substance or to engage in the activity that will addict them, and they have a risk of relapse no matter how successful their treatment is.
  • People with addictions tend to be risk takers and thrill seekers; the changes in brain circuitry lead drug abusers to expect a positive reaction to their addictive substance or activity before they use it or experience it.
  • Self-regulation and impulse control around the person's drug of choice are difficult for people with addictions. However, often these same people retain impulse control in most or all other areas of their life. This is more true with drugs like alcohol and less true with drugs like methamphetamine. Again, this difference is thought to be related to how stimulating the drug is to the reward circuits (dopamine tracts) in the brain. Methamphetamine is much more rewarding to the brain than alcohol.

When to Seek Medical Care for Addiction

  • Some people are able to recover from an addiction without help. However, it is thought that most people need assistance. Many times medical, psychiatric, or psychological assistance is needed. With treatment and support, many individuals are able to stop their drug abuse.
  • If there are known or suspected health problems related to substance abuse, it is wise to consult with a primary-care physician for a full history and physical exam. Examples include assessing for liver damage in advanced cases of alcohol addiction or dental damage due to methamphetamine abuse.
  • When talking with a loved one about addiction, having a third party present who is professionally trained and knowledgeable about addiction may be helpful. Being in a relationship with a drug abuser can change the relationship and lead to a decreased ability to communicate with each other.

Questions to Ask the Doctor

If you or a loved one is suffering from drug abuse, it can be hard to talk to a medical professional about it. It is helpful to find a doctor who is familiar and comfortable dealing with people who suffer from drug abuse. Unfortunately, some in the medical profession suffer from the same misperceptions and false ideas as many in the general public. However, most medical professionals do not have this prejudice and can direct you to local resources for help. After finding someone with whom you can work, some of the following questions may be helpful:

  • Can you test my liver or kidneys to assess for damage?
  • Are there other body systems that my drug use may have affected?
  • Are there any medications that may be helpful in treating my addiction?
  • Where can my family get support and information about drug abuse?

What Are Addiction Treatments?

  • Treatment must be individualized, because no single treatment is appropriate for everyone or for each type of drug abuse.
  • Treatment is most effective when it is readily available.
  • Effective treatment often needs to address the multiple needs of the individual, not just his or her addiction.
  • As with all medical care, the treatment plan must be assessed continually and modified as a person's condition changes.
  • Remaining in a treatment program or participating in a treatment plan for an adequate amount of time is critical for the treatment to be effective. Research indicates that, for most patients, significant improvement generally begins about three months into treatment.
  • Behavior change is the most important element for effective treatment of addiction. Often this requires counseling or behavior modification treatment.
  • Medications can be an important part of treatment for some types of drug abuse, especially when combined with counseling and other behavioral therapies.
  • There is a significant amount of evidence that individuals with addictions and coexisting mental disorders (such as depression or anxiety disorders) should have both disorders treated in an integrated way.
  • Treatment does not have to be voluntary to be effective. For example, motivation by employers or family members can encourage people with addictions to seek out and continue treatment. This is thought to be the reason that physicians and nurses have some of the best recovery rates.
  • If appropriate, monitoring drug use during treatment, through urinalysis or other tests, can help a person withstand the urges to use drugs. Also, monitoring can provide early evidence of drug use so that the individual's treatment plan can be adjusted if he or she is still using drugs.
  • During treatment, individuals may need to be evaluated and tested for infectious diseases such as HIV/AIDS, hepatitis B, hepatitis C, and tuberculosis. Treatment needs to include counseling to help the person change high-risk behavior or to deal with an existing disease.
  • Recovery from addiction can be a long-term process and can require more than one episode or type of treatment.

Medical Treatment

Medical detoxification (often simply referred to as detox) is needed for some addictions such as severe alcohol abuse. Detox is indicated only for some types of substance abuse. When needed, detox is only the first stage of addiction treatment and without further treatment does little to change long-term drug use. During medical detoxification, the acute physical symptoms of withdrawal associated with discontinuation of drug use are safely treated. This alone is rarely sufficient to help people with addictions in the long term, but for some individuals, it is a precursor to effective drug-addiction treatment.


Medications are an important element of therapy for many patients, especially when combined with counseling and other behavioral therapies. Methadone, buprenorphine (Suboxone), and levo-alpha-acetylmethadol (LAAM) can be prescribed for individuals addicted to heroin or other opiates. Naltrexone can be prescribed for some people addicted to alcohol and those with co-occurring opiate and alcohol dependence. Acamprosate (Campral) is an agent to help in maintaining abstinence in people with alcohol dependency. A nicotine replacement product (such as patches or gum) or an oral medication (such as bupropion) can be an effective component of therapy for people addicted to nicotine. For people with psychiatric disorders, both behavioral treatments and medications can be critically important.


At the current time, there is no indication for surgery for any type of substance or alcohol abuse or addiction.

Other Therapy

Behavioral therapy or counseling may be used to accomplish the following:

  • Encourage and increase motivation for change from using an addicting drug
  • Help build skills to resist addiction-related activities
  • Replace addiction-related activities with more constructive and rewarding activities
  • Improve problem-solving abilities
  • Improve interpersonal relationships, including the individual's ability to function in the family and community

Family members, friends, and coworkers can play critical roles in motivating individuals with drug problems to enter and stay in treatment. Family therapy is often important, especially for adolescents. The involvement of a family member in an individual's treatment program can strengthen and extend the benefits of the program.

Is It Possible to Prevent Addiction?

Researchers show that children who start drinking when younger than 15 years are four times more likely to have an alcohol addiction by the age of 21 years. Talking with children early about the negative effects of alcohol and drugs may help guide them to healthier behaviors.

The potential for relapse is part of chronic (long-term) disease. Because addiction is a chronic disease, prevention of relapse is essential. The person must learn new behaviors so he or she can either avoid the trigger or refuse to turn to drugs. The key to long-term avoidance of addiction is having a maintenance or relapse plan.

Support Groups and Counseling

Hundreds of support groups are available for any kind of addiction, whether it is an addiction to drugs or an addiction to a certain behavior. The Internet may be a helpful way to find such support groups.

Counseling (individual and/or group) is often an essential part of treatment and prevention of relapse. Counselors may provide information regarding relevant support groups.

For More Information on Addiction

National Institute on Drug Abuse
National Institutes of Health
6001 Executive Boulevard, Room 5213
Bethesda, MD 20892-9561
(301) 443-1124
[email protected]

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Reviewed on 1/26/2022
Medically reviewed by Marina Katz, MD; American Board of Psychiatry & Neurology


"Substance use disorder: Principles for recognition and assessment in general medical care."