Glossary of Addiction Terms

Specific terminology, acronyms and abbreviations are a big part of life for those seeking recovery. We’ve put together two guides to help you navigate the terminology you may hear or read as part of you or your loved ones recovery journey.

This guide is specifically about addiction terminology.

Please refer to our Guide to Abbreviations for specifics related to drugs, mental health and more extensive addiction treatment abbreviations.

Levels of Care

Medical Detox

Detoxification is the process of stopping all drug and alcohol use and allowing these substances to safely clear from the body. Medical detoxification takes place with the support and supervision of medical professionals; when needed, the treatment team may administer treatment medications to manage withdrawal as safely and comfortably as possible, as well as address any withdrawal complications that arise during the detox period.1
Several substances—including opioids, alcohol, and sedative drugs—are associated with significantly painful, uncomfortable, and sometimes dangerous withdrawal syndromes. The goal of a medical detox is to create a safe, comfortable environment for the patient while he or she withdraws from the toxic effects of drugs and/or alcohol.1
Detox is not a replacement for comprehensive addiction treatment; rather, it is often the first step in the recovery process that helps to ease a patient’s transition into longer-term substance rehabilitation efforts.1

Residential Treatment

Residential programs provide addiction treatment in an inpatient setting, offering a sober environment that a patient may live in for the length of his or her rehabilitation stay. Medical and clinical staff are on site to supervise patients 24/7.2
Residential treatment offers a structured environment for the patient, creating a routine of group and one-on-one therapy. Different programs may provide treatment at varying levels of intensity, including access to clinical services, as well as the incorporation of appropriate holistic treatments and other approaches as the patient and staff see necessary.2

Partial Hospitalization Program

Also known as PHP or day treatment, partial hospitalization programs are similar in setting and structure to residential treatment, except the patient doesn’t live on the premises where addiction treatment occurs. Instead, they spend several hours a week in individual and group therapy, and head home or to a sober living facility for their free time. Many PHPs have close clinical and administrative ties to hospital programs, which facilitates patient access to clinical services and an escalation of level of care, should it be necessary.1
A partial hospitalization program is often part of a continuum of care: many patients step down from an inpatient medical detox or residential treatment to PHP as they transition through their treatment and recovery.1

Intensive Outpatient Program

An intensive outpatient program, or IOP, is a step in the continuum for addiction treatment. Requiring relatively fewer hours in a day of therapy, IOPs are often the next step for patients who have graduated from a higher level of care, such as a residential or inpatient rehabilitation program.

Outpatient Program

Many standard outpatient programs are relatively less time-intensive than an IOP or PHP program for addiction treatment. Patients can expect to attend therapy sessions 1 to 2 days a week, focused on what the patient needs most.
The patient does not live on the grounds of the facility like they do for a residential treatment program, and instead commutes to the facility for their treatment.

Aftercare Program

For most people, recovery efforts continue beyond successful completion of an initial substance rehabilitation program. Often, addiction treatment facilities host aftercare programs (or will make plans for your aftercare programming elsewhere), which set the patient up with continued access to the tools, skills, and resources needed to confront the real-world struggles of relapse and addiction beyond treatment.
Although aftercare offerings from one location to the next, you might expect recommendations for continued care with psychiatrists and therapists, sober living facility recommendations, a resource to contact at a treatment center with questions or concerns, participation in alumni group meetings or other mutual support groups, and more.

Industry Terms


Addiction is a chronic disease whose development may be influenced by several factors, including but not limited to a person’s genetics, how their brain circuits interact, the person’s experiences, as well as their environment. People who are addicted to a substance may engage in risky, compulsive drug seeking and drug use behavior.3
Addiction is treatable, often with the assistance of medical and mental health professionals.3

Substance Use Disorder

A substance use disorder (SUD) is characterized by the chronic, repeated use of a substance—drugs or alcohol—despite the use of the substance causing physical, mental, or interpersonal problems for the user.4
Substance use disorders are diagnosed as specific mental health disorders, and often referred to simply as addiction.4

Co-Occurring Disorders

When a person has a substance use disorder and a mental health disorder at the same time, they are referred to as a co-occurring disorders. Each presentation of a co-occurring disorder can be different. Sometimes, the substance abuse can lead to the mental health disorder; other times, the mental health disorder precipitates the substance abuse.
Treatment of a co-occurring disorder should approach both the substance abuse and the mental health disorder with the same gravity and at the same time for a better recovery outcome.


Relapse is often a common part of recovery from addiction. Several variables may factor into relapse. In some instances, after a drug user attempts to quit using a substance, the arrival of withdrawal symptoms can perpetuate the compulsive drive for continued drug use, resulting in early relapse.5


When a person stops using a substance, they may experience withdrawal symptoms. Although withdrawal symptoms vary from substance to substance, there may be a higher risk of withdrawal if the user has built up significant physiological tolerance to alcohol or the drug in question, which itself is more likely after repeated use or consistent use over time.5
Some commonly experienced withdrawal symptoms include physical effects like muscle aches, cramping, nausea, and vomiting, as well as psychological effects such as stress or anxiety. Different drugs will have different withdrawal symptoms.5
Some withdrawal symptoms, like seizures, can be dangerous, which is why detoxing in a medically supervised environment is often recommended for certain types of substances. Withdrawal can present significant challenges to recovery. Left unmanaged, the user might turn back to their substance of choice for relief from unpleasant symptoms.5

Addiction Treatment

Medication-Assisted Treatment (MAT)

In certain instances, addiction treatment requires the use of medication-assisted treatment, also known as MAT. While undergoing counseling and therapy, patients will also take medications that help with the management of their addiction.6
There are several FDA-approved drugs that treat both opioid and alcohol use disorders.6

Cognitive Behavioral Therapy (CBT)

Used to help people dealing with mental health disorders, several mental illness, and addiction to drugs or alcohol, cognitive behavioral therapy helps people to identify problematic thought processes that, left unchecked, can contribute to maladaptive behaviors. Strategies can then be devised to change these dysfunctional thoughts so that they no longer lead to the unhealthy “target” behaviors.2
Also known as CBT, cognitive behavioral therapy is often one of the tentpoles of addiction treatment, and is commonly utilized alongside of other behavioral therapeutic techniques and medications.2

Motivational Interviewing

In some instances, a person with a substance use disorder might not yet have accepted they have a problem they need help with. Motivational interviewing can help the person in treatment decide to get well for themselves, rather than for an external reason or another person.7

12-Step Program

With its roots in Alcoholics Anonymous (AA), 12-step programs provide community and knowledge of addiction and recovery for free for those suffering from a substance use disorder.
Many suggestions made in aftercare encourage the patient to seek out a local 12-step program. Some alumni programs at addiction treatment facilities also host 12-step meetings of their own.