Opioid Use Disorder (OUD) is the chronic use of opioids that causes clinically significant distress or impairment. Opioid use disorders affect over 16 million people worldwide, over 2.1 million in the United States, and there are over 120,000 deaths worldwide annually attributed to opioids. OUD consists of an overpowering desire to use opioids, increased opioid tolerance, and withdrawal syndrome when discontinued.

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Substances of abuse activate the circuit in the brain that is associated with processing rewards, and cause the subjective feeling of euphoria, or a “high.”  When patients use opioids daily for many weeks, they become physically dependent on the drug. As a result, when they abruptly stop taking the drug several symptoms emerge that are unrelated to the reward circuit, such as increasing heart rate, sweatiness and intense craving. These symptoms are called withdrawal. Many people who develop opioid use disorder also develop a phenomenon called tolerance, where they need to take higher doses of opioids to feel the same effects.

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In order to qualify for a diagnosis of opioid use disorder, not only do individuals need to use opioids compulsively, but they would also have to be spending significant amount of time in finding, getting, and using opioids. The use of opioids would have to cause significant dysfunction in fulfilling major social or vocational obligations and also cause physical or psychological harm.