Also known as an opioid use disorder, it is a problematic pattern of opioid use leading to clinically significant impairment or distress, as manifested by at least two of the following, occurring within a 12-month period:

- Taking larger amounts of opioids or taking opioids over a longer period than was intended.
- Experiencing a persistent desire for the opioid or engaging in unsuccessful efforts to cut down or control opioid use.
- Spending a great deal of time in activities necessary to obtain, use, or recover from the effects of the opioid.
- Craving, or a strong desire or urge to use opioids.
- Using opioids in a fashion that results in a failure to fulfill major role obligations at work, school, or home.
- Continuing to use opioids despite experiencing persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of opioids.
- Giving up or reducing important social, occupational, or recreational activities because of opioid use.
- Continuing to use opioids in situations in which it is physically hazardous to do so.
- Continuing to use opioids despite knowledge of having persistent or recurrent physical or psychological problems that are likely to have been caused or exacerbated by the substance.
- Tolerance, as defined by either a need for markedly increased amounts of opioids to achieve intoxication or the desired effect, or a markedly diminished effect with continued use of the same amount of an opioid.
- Withdrawal, as manifested by either the characteristic opioid withdrawal syndrome, or taking opioids to relieve or avoid withdrawal symptoms.

Opioid abuse can be classified by severity as mild, moderate, or severe.

Adapted from American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, DC. American Psychiatric Association. 2013. p. 541.