Substance Use Prevention and Treatment Glossary

Substance use disorder is a chronic, relapsing disease affecting more than 20 million Americans. This glossary helps explain many of the terms associated with substance use disorders, including medications and behavioral therapies proven to help treat them.

Addiction.

A chronic, relapsing disease characterized by compulsive (or difficult to control) drug seeking and use despite harmful consequences, as well as long-lasting changes in the brain.

Alcohol use disorder (AUD).

A chronic relapsing brain disease characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences.

Buprenorphine.

Buprenorphine is an opioid partial agonist, which binds to and activates a receptor to a lesser degree than a full agonist. It produces effects such as euphoria or respiratory depression. With buprenorphine, however, these effects are weaker than those of full agonists, such as heroin and methadone.

Cognitive behavioral therapy.

A form of psychotherapy that teaches people strategies to identify and correct problematic associations among thoughts, emotions, and behaviors to enhance self-control and reduce drug use.

Contraindication.

Conditions for which a medication should not be prescribed due to potentially harmful effects to the user.

Dependence.

A condition characterized by withdrawal symptoms that can occur when the regular use of alcohol, illicit drugs, or some prescription drugs ceases, even if taken as prescribed. A person can be dependent on a substance without being addicted.

Fentanyl.

A powerful synthetic opioid that is similar to morphine but 50 to 100 times more potent.

Harm reduction.

A set of strategies and ideas aimed at reducing negative consequences associated with drug use (e.g., syringe services programs allow people who inject drugs to obtain sterile needles or syringes and safely dispose of used needles).

Health home.

A model of care that offers coordinated care to individuals with multiple chronic health conditions, including mental health and substance use disorders.

Illicit.

Illegal or forbidden by law.

Integrated care.

The coordination of substance use, mental health, and primary care services.

Medical detoxification.

A process in which the body rids itself of a drug or its metabolites. Medically assisted detoxification may be needed to help manage a person’s withdrawal symptoms.

Medication-assisted treatment.

Traditionally defined as a combination of behavioral therapies and medications approved by the U.S. Food and Drug Administration to treat opioid use disorder or alcohol use disorder. However, referring to this gold standard of care as “medication-assisted” suggests, incorrectly, that the medicines are not integral to the therapy, so Pew no longer uses this term. Instead, it’s best to be precise and talk about exactly which type of treatment is being used: either “medications for opioid use disorder” or “behavioral therapies” (such as counseling or cognitive behavioral therapy)—or both.

Medication unit.

A facility that is geographically separated but affiliated with an opioid treatment program. Professionals can administer medications, such as methadone, for opioid use disorder and conduct drug testing from these facilities. However, initiation of medication and counseling must be conducted at the main opioid treatment program.

Methadone.

One of the three medications approved by FDA to treat opioid use disorder. The drug must typically be administered daily in an opioid treatment program, which must be certified by the Substance Abuse and Mental Health Services Administration and registered with the U.S. Drug Enforcement Administration.

Morphine milligram equivalents (MMEs).

A measure that compares an opioid dose’s potency to that of morphine.

Naloxone.

An opioid antagonist that effectively blocks the effects of opioids if they are used. Naloxone is widely used as an opioid overdose reversal agent.

Naltrexone.

One of the three medications approved by FDA to treat opioid use disorder. It blocks the effects of opioids if they are used and can be prescribed by any health care provider who is licensed to prescribe medications. It can be received orally or by injection. Medical guidance states that to reduce the risk of rapid and intense withdrawal symptoms, patients should abstain from opioids for a minimum of seven to 10 days before starting naltrexone.

Neonatal abstinence syndrome (NAS).

A group of conditions caused when a baby withdraws from certain drugs he or she is exposed to in the womb. NAS may also be referred to as NOWS (neonatal opioid withdrawal syndrome), which is similar, but caused only by opioids.

Office-based opioid treatment (OBOT) program.

Outpatient treatment in which buprenorphine can be provided. This approach seeks to integrate opioid addiction treatment into the general medical and psychiatric care of the patient to achieve and sustain remission.

Opioid agonist.

A chemical substance that binds to and activates opioid receptors on cells, causing a biological response. Opioid agonists can be prescription analgesics, medications used to treat opioid use disorder, illicit drugs, or naturally occurring substances found in the body. Examples include oxycodone, morphine, heroin, fentanyl, methadone, and endorphins.

Opioid agonist therapy (OAT).

A treatment for opioid use disorder that uses opioid agonists, such as methadone or buprenorphine, which bind to the same receptors in the brain activated by the drug of misuse, but in a safer and more controlled manner. These medications reduce withdrawal symptoms and cravings.

Opioid antagonist.

A chemical substance that binds to and blocks the activation of opioid receptors on cells, preventing a biological response. Naloxone is an example of an opioid antagonist.

Opioid receptors.

Proteins on the surface of neurons or other cells that are activated by endogenous opioids, such as endorphins, and drugs such as heroin.

Opioid treatment program (OTP).

The only facility where patients can receive methadone for opioid use disorder. OTPs are regulated and certified by the Substance Abuse and Mental Health Services Administration and can exist in a number of care settings, including intensive outpatient, residential, and hospital settings.

Opioid use disorder (OUD).

A chronic disease characterized by a problematic pattern of opioid use that leads to clinically significant impairment or distress.

Overdose.

Injury to the body that results from taking a drug in excessive amounts; can be fatal or nonfatal.

Partial agonist.

A substance that binds to and activates a receptor to a lesser degree than a full agonist.

Polysubstance use.

Broadly describes the consumption of more than one drug over a defined period, simultaneously or at different times, for either therapeutic or recreational purposes.

Prescription drug misuse.

The use of a medication in ways or amounts other than those intended by a prescriber, by someone other than the person for whom the medication is prescribed, or for the experience or feeling the medication causes.

Prescription drug monitoring program (PDMP).

A state-based electronic database that contains information on controlled substance prescriptions dispensed by pharmacies and prescribers.

Receptor.

Located on human cells, receptors are places on which a drug or substance binds to either cause or block an effect.

Recovery.

A process of change through which people with substance use disorders improve their health and wellness, live self-directed lives, and strive to reach their full potential.

Recovery support services.

Any service, such as mentoring and case management, designed to initiate, support, and enhance recovery.

Re-entry.

A broad term used to refer to issues related to the transition of individuals from prison or jail to the community.

Relapse.

A process in which an individual who has established abstinence or sobriety experiences recurrence of signs and symptoms of active addiction.

Remission.

A state of wellness in which there is an abatement of signs and symptoms that characterize active addiction.

Stigma.

A set of negative attitudes and beliefs that motivate people to fear and discriminate against other people.

Substance use disorder (SUD).

A medical illness characterized by clinically significant impairments in health, social function, and control over substance use. SUDs are diagnosed by assessing cognitive, behavioral, and psychological symptoms.

Syringe services programs.

Community-based prevention programs that can provide a range of services, including linkage to substance use disorder treatment; access to and disposal of sterile syringes and injection equipment; and vaccination, testing, and linkage to care and treatment for infectious diseases.

Tolerance.

A state of adaptation in which exposure to a drug induces changes that result in diminution of one or more of the drug’s effects over time.

Withdrawal.

Symptoms that can occur after long-term use of a drug is reduced or stopped; these symptoms occur if tolerance to a substance has occurred and vary depending on the substance.