Opioid use disorder (OUD)

Opioid use disorder is a chronic medical condition involving problematic use of prescription or illicit opioids that leads to impairment, distress and physical dependence.

Opioids such as oxycodone, heroin and fentanyl act on receptors that blunt pain and produce euphoria, and repeated use changes brain circuits governing reward and stress. Features include cravings, tolerance, withdrawal symptoms when use stops, and continued use despite harm to health, relationships or work. Overdose is a major risk because opioids suppress breathing. The disorder can begin after medical prescribing or through non-medical use.

Diagnosis follows criteria from the DSM-5 based on the number of symptoms present over a year, with severity rated as mild, moderate or severe. Medications for opioid use disorder, including buprenorphine, methadone and naltrexone, combined with counseling are the established standard of care. Cannabidiol has been studied in early trials for cue-induced craving, and there is no approved cannabinoid use in this condition.