American Society of Addiciton Medicine

Glossary of Addiction

Quality Care

Glossary of Addiction

Helping inform perspective and language on medication use for the treatment of substance use disorders

Definition of Addiction


All definitions and terms are updated and approved by both the ASAM Quality Improvement Council and the ASAM Board of Directors. These definitions are important in helping inform the perspective on medication use for the treatment of substance use disorders.

November 24, 2021


Addiction is a treatable, chronic medical disease involving complex interactions among brain circuits, genetics, the environment, and an individual’s life experiences. People with addiction use substances or engage in behaviors that become compulsive and often continue despite harmful consequences. See full language.

Addiction Medications

Medications specifically indicated for and prescribed to treat substance use disorders (e.g., buprenorphine for opioid use disorder, varenicline for tobacco use disorder), both as an initial lifesaving and motivational engagement strategy (i.e., withdrawal management) as well as part of a long-term treatment plan similar to other chronic diseases such as bipolar disorder or diabetes.

Medication for Addiction Treatment (MAT)

When the acronym MAT is used or referenced in laws, regulations, academic literature, the media, and the vernacular, we recommend reading MAT as medication for addiction treatment. This term takes into account all manifestations of addiction and indicates that there are medications specifically tailored for treatment. ASAM recommends the term MAT be retired from use and instead use the term addiction medications to refer to pharmacotherapy for substance use disorders.


Opiate refers to opioids derived from the naturally occurring alkaloid compounds produced in the opium poppy, Papaver somniferum, and includes morphine, codeine, and thebaine.


Opioid is a term that designates all compounds, natural and synthetic, exogenous and endogenous, that bind to and activate any of the opioid receptors.