Substance Use Disorders



Any pattern of substance use causing significant physical, mental, or social dysfunction

  • Substances of abuse include:
    • Alcohol
    • Cannabis (marijuana, hashish, cannabis oil, extracts); also sold as highly concentrated extracts for use in vaporizers
    • “Club drugs” (MDMA [ecstasy, Molly], PMMA [Superman], flunitrazepam, γ-hydroxybutyrate [GHB])
    • Dissociative drugs (ketamine, phencyclidine [PCP], tenocyclidine [TCP])
    • Hallucinogens (lysergic acid diethylamide [LSD], salvia, ayahuasca, N,N-dimethyltryptamine [DMT])
    • Inhalants (glue, paint thinners, nitrous oxide)
    • Opioids (carfentanil and other synthetic analogs of fentanyl, heroin, kratom, desomorphine [Krokodil], U-47700 [Pink])
    • Prescription medications
      • CNS depressants (barbiturates, benzodiazepines, hypnotics)
      • Dextromethorphan (“Robo tripping”)
      • Opioids and morphine derivatives (fentanyl, hydrocodone, oxycodone, others)
      • Stimulants (amphetamines, methylphenidate)
    • Stimulants (cocaine, amphetamines, methamphetamines, khat)
    • Synthetic cannabinoids (Spice, K2, fake weed); often much more potent than marijuana; may be smoked or vaporized
    • Synthetic cathinones (bath salts, alpha-PVP [Flakka])
    • Tobacco



  • 61.2 million Americans (21.9%) reported illicit drug use in the past year in 2021.
  • 14.1% of 12- to 17-year-olds; 38% of 18- to 25-year-olds
  • 1 in 3 (35.4%) young adults used marijuana in the past year.
  • Opioid overdose is the leading cause of death for persons 26 to 38 years of age in the United States. More than 82% of these are due to synthetic opioids. There have been increasing cases of overdose and death related to synthetic opioids mixed with xylazine, which does not respond to naloxone administration.
  • Many states require naloxone to be prescribed or offered when issuing a prescription of opioids to patients at increased risk of overdose, such as those receiving ≥50 morphine milligram equivalents per day of an opioid, those taking both opioids and benzodiazepines, and those with a history of substance abuse.

Etiology and Pathophysiology

Substances of abuse affect dopamine and other neurotransmitter receptors. Variant alleles may account for differences in susceptibility to misuse of different substances.

Risk Factors

  • Academic problems, school dropout
  • Criminal involvement
  • Depression, anxiety
  • Family dysfunction or trauma
  • Family history
  • Peer or family use or approval
  • Unemployment, low socioeconomic status

General Prevention

  • Prescribe nonnarcotic therapies to treat pain and when necessary, use limited amounts to treat acute severe pain.
  • Avoid prescribing narcotics for chronic conditions.
  • Early identification and aggressive early intervention improve outcomes.
  • Universal school-based interventions are modestly effective for prevention.

There's more to see -- the rest of this topic is available only to subscribers.