Alcohol and drug use is one of the leading causes of preventable illnesses and premature death nationwide.


What Is a Substance Use Disorder or an Addiction?

Substance use disorder (SUD) is complex a condition in which there is uncontrolled use of a substance despite harmful consequence.

People with SUD have an intense focus on using a certain substance(s) such as alcohol, tobacco, or illicit drugs, to the point where the person’s ability to function in day to day life becomes impaired.


People keep using the substance even when they know it is causing or will cause problems.

The most severe SUDs are sometimes called addictions.


People can develop an addiction to:

  • Alcohol
  • Marijuana
  • PCP, LSD and other hallucinogens
  • Inhalants, such as, paint thinners and glue
  • Opioid pain killers, such as codeine and oxycodone, heroin
  • Sedatives, hypnotics and anxiolytics (medicines for anxiety such as tranquilizers)
  • Cocaine, methamphetamine and other stimulants
  • Tobacco

People with a substance use disorder may have distorted thinking and behaviors.

Changes in the brain’s structure and function are what cause people to have intense cravings, changes in personality, abnormal movements, and other behaviors.

Brain imaging studies show changes in the areas of the brain that relate to judgment, decision making, learning, memory, and behavioral control.


Repeated substance use can cause changes in how the brain functions.

These changes can last long after the immediate effects of the substance wears off, or in other words, after the period of intoxication.


Intoxication is the intense pleasure, euphoria, calm, increased perception and sense, and other feelings that are caused by the substance. Intoxication symptoms are different for each substance.

When someone has a substance use disorder, they usually build up a tolerance to the substance, meaning they need larger amounts to feel the effects.


According to the National Institute on Drug Abuse, people begin taking drugs for a variety of reasons, including:

  • to feel good — feeling of pleasure, “high” or "intoxication"
  • to feel better — relieve stress, forget problems, or feel numb
  • to do better — improve performance or thinking
  • curiosity and peer pressure or experimenting

In addition to substances, people can also develop addiction to behaviors, such as gambling (gambling disorder).   


People with substance use and behavioral addictions may be aware of their problem but not be able to stop even if they want and try to.

The addiction may cause physical and psychological problems as well as interpersonal problems such as with family members and friends or at work.

Alcohol and drug use is one of the leading causes of preventable illnesses and premature death nationwide.


Symptoms of substance use disorder are grouped into four categories:

Learn more about
Stigma, Prejudice and Discrimination Against People with Mental Illness

  • Impaired control: a craving or strong urge to use the substance; desire or failed attempts to cut down or control substance use
  • Social problems: substance use causes failure to complete major tasks at work, school or home; social, work or leisure activities are given up or cut back because of substance use
  • Risky use: substance is used in risky settings; continued use despite known problems
  • Drug effects: tolerance (need for larger amounts to get the same effect); withdrawal symptoms (different for each substance)

Many people experience substance use disorder along with another psychiatric disorder.

Oftentimes another psychiatric disorder precedes substance use disorder, or the use of a substance may trigger or worsen another psychiatric disorders.

  • How Is Substance Use Disorder Treated
  • Effective treatments for substance use disorders are available.+


    The first step is recognition of the problem.

    The recovery process can be delayed when a person lacks awareness of problematic substance use.

    Although interventions by concerned friends and family often prompt treatment, self-referrals are always welcome and encouraged.


    A medical professional should conduct a formal assessment of symptoms to identify if a substance use disorder is present.

    All patients can benefit from treatment, regardless of whether the disorder is mild, moderate, or severe.

    Unfortunately, many people who meet criteria for a substance use disorder and could benefit from treatment don’t receive help.


    Because SUDs affect many aspects of a person’s life, multiple types of treatment are often required.

    For most, a combination of medication and individual or group therapy is most effective.


    Treatment approaches that address an individual’s specific situation and any co-occurring medical, psychiatric, and social problems is optimal for leading to sustained recovery.


    Medications are used to control drug cravings, relieve symptoms of withdrawal, and to prevent relapses.

    Psychotherapy can help individuals with SUD better understand their behavior and motivations, develop higher self-esteem, cope with stress, and address other psychiatric problems.

    A person’s recovery plan is unique to the person’s specific needs and may include strategies outside of formal treatment.


    These may include:

    • Hospitalization for medical withdrawal management (detoxification)
    • Therapeutic communities (highly controlled, drug-free environments) or sober houses
    • Outpatient medication management and psychotherapy
    • Intensive outpatient programs
    • Residential treatment (“rehab”)
    • Many people find mutual-aid groups helpful (Alcoholics Anonymous, Narcotics Anonymous, SMART Recovery)
    • Self-help groups that include family members (Al-Anon or Nar-Anon Family Groups)

    13 principles of effective drug addiction treatment


    These 13 principles of effective drug addiction treatment were developed based on three decades of scientific research.

    Research shows that treatment can help drug-addicted individuals stop drug use, avoid relapse and successfully recover their lives.

    1. Addiction is a complex, but treatable, disease that affects brain function and behavior.
    2. No single treatment is appropriate for everyone.
    3. Treatment needs to be readily available.
    4. Effective treatment attends to multiple needs of the individual, not just his or her drug abuse.
    5. Remaining in treatment for an adequate period of time is critical.
    6. Counseling— individual and/or group —and other behavioral therapies are the most commonly used forms of drug abuse treatment.
    7. Medications are an important element of treatment for many patients, especially when combined with counseling and other behavioral therapies.
    8. An individual’s treatment and services plan must be assessed continually and modified as necessary to ensure it meets his or her changing needs.
    9. Many drug-addicted individuals also have other mental disorders.
    10. Medically assisted detoxification is only the first stage of addiction treatment and by itself does little to change long-term drug abuse.
    11. Treatment does not need to be voluntary to be effective.
    12. Drug use during treatment must be monitored continuously, as lapses during treatment do occur.
    13. Treatment programs should assess patients for the presence of HIV/AIDS, hepatitis B and C, tuberculosis and other infectious diseases, as well as provide targeted risk-reduction counseling to help patients modify or change behaviors that place them at risk of contracting or spreading infectious diseases.

    Source: National Institute on Drug Abuse. These principles are detailed in NIDA’s Principles of Drug Addiction Treatment: A Research-Based Guide.


  • How to Help

Related Conditions

Opioid Use Disorder

Opioids produce high levels of positive reinforcement, increasing the odds that people will continue using them despite negative resulting consequences.

Opioid use disorder is a chronic lifelong disorder, with serious potential consequences including disability, relapses, and death.

The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition describes opioid use disorder as a problematic pattern of opioid use leading to problems or distress.

Learn More


Gambling Disorder

In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), gambling disorder is included in a new category on behavioral addictions.

This reflects research findings that gambling disorder is similar to substance-related disorders in many ways.

Recognizing these similarities will help people with gambling disorder get needed treatment and services, and may help others better understand the challenges.

Learn More


Internet Gaming Disorder

Internet gaming disorder is included in DSM-5 in the section of disorders requiring further research. This reflects the scientific literature showing that persistent and recurrent use of Internet games, and a preoccupation with them, can result in clinically significant impairment or distress.

The condition criteria do not include general use of the Internet or social media.


Caffeine Intoxication and Withdrawal

Caffeine intoxication and caffeine withdrawal are included in DSM-5.

Caffeine use disorder, however, is in the section of DSM-5 for conditions requiring further research.


While there is evidence to support this as a disorder, experts conclude it is not yet clear to what extent it is a clinically significant disorder.


More Information