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Defining Opioid Use Disorder (OUD) and Medication for Opioid Use Disorder (MOUD)

The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines opioid use disorder (OUD) as a “problematic pattern of opioid use leading to clinically significant impairment or distress.” OUD involves misuse of heroin and prescribed opioid medications.

The DSM-5 outlines the following diagnostic criteria for OUD:

  1. Taking large amounts of opioids
  2. Unsuccessful efforts to reduce opioid use
  3. Craving opioids
  4. Failure to fulfill obligations (for example at work, school, home) due to opioid use
  5. Social or interpersonal problems as a result of opioid use
  6. Continued opioid use despite physical or psychological problems that are likely caused or exacerbated by the opioids
  7. Exhibiting tolerance and/or withdrawal

Medication for Opioid Use Disorder (MOUD) is an evidence-based approach that uses medication to treat individuals with OUD. Previously, the field used the term Medication-Assisted Treatment (MAT) to describe “the use of medications, in combination with counseling and behavioral therapies, to provide a 'whole patient' approach to the treatment of substance use disorders.” However, the field is shifting away from the use of the term MAT. Instead, experts recommend using Medication for Opioid Use Disorder (MOUD) to emphasize that medication itself is the treatment for OUD. This toolkit refers to “MOUD” but certain programs or resources may refer to “MAT.”

There are three medications typically used for treating OUD and approved by the FDA:

  • Buprenorphine
  • Methadone
  • Naltrexone

These three medications are effective in treating OUD and are clinically proven to:

  • Safely replace the opioids
  • Block the opioid effects on the brain
  • Normalize brain chemistry and body functions
  • Relieve physiological cravings

The FDA advises that any patient who seeks treatment for OUD have the choice between all three approved medications (buprenorphine, methadone, and naltrexone) to determine which is best for them and meets their treatment needs. There are many factors to consider when determining which medication is best for a patient, such as patient preference, medication availability, risk of overdose, and accessibility of treatment settings.

Some medications must be delivered in specific treatment settings. Methadone must be delivered by an opioid treatment program (OTP), while buprenorphine, for example, can be delivered in a number of settings including office-based opioid treatment (OBOT), outpatient treatment programs, or residential treatment programs. The table below summarizes the different treatment settings in which each medication can be provided.

Medication Treatment Setting
  • Office-based opioid treatment
  • Outpatient substance use disorder (SUD) treatment program
  • Residential treatment program
  • Opioid treatment program (OTP)
  • OTP
  • Office-based treatment
  • Outpatient SUD treatment program
  • Residential SUD treatment program
Source: Adapted from Medications for Opioid Use Disorder: For Healthcare and Addiction Professionals, Policymakers, Patients, and Families, Substance Abuse and Mental Health Services Administration

In addition to MOUD, there are other evidence-based treatment models that can be used to identify and treat OUD, including Screening, Brief Intervention and Referral to Treatment (SBIRT) and behavioral therapy models. Promising care delivery modules include telehealth models, case management models, and integration of mental health services in primary care settings.