Early Substance Use Linked to Higher Rates of Polysubstance Use Disorders
Despite slight decreases in overall overdose deaths in recent years, deaths involving multiple drugs have risen over time. A study published in Molecular Psychiatry examined the prevalence of U.S. adults who had multiple substance use disorders––also known as a polysubstance use disorder––and whether the age they first used substances was associated with the number of disorders they experienced.
Researchers analyzed data from 92,233 adults who participated in the 2022-2023 National Survey on Drug Use and Health. The study included substance use and SUDs related to alcohol, nicotine, cannabis, opioids, stimulants, sedatives or tranquilizers, cocaine, hallucinogens, methamphetamine, and inhalants.
The findings varied by substance. Among adults with methamphetamine, cocaine, or hallucinogen use disorder, about half or more had three or more substance use disorders. Adults with opioid use disorder or prescription stimulant, sedative, or tranquilizer use disorders also frequently had multiple disorders. In contrast, about two-thirds of adults with alcohol use disorder had no other substance use disorder.
The researchers also found that age of first substance use was associated with the number of substance use disorders. Compared with adults who began using substances before age 18, those who began at age 21 or older had 73% to 83% fewer substance use disorders, depending on the analysis. Later initiation of alcohol or cannabis use was also associated with fewer moderate to severe disorders. These results show a relationship between age of initiation and substance use disorders, but they cannot establish that starting later directly caused the difference.
Key Findings
Multiple substance use is common but varies by primary substance. Among adults who reported using a specific substance in the past year, 15.3% of those who used alcohol and 29.8% of those who used tobacco or vaped nicotine also reported using four or more substances. The percentages were higher among those who used cannabis (39.1%), opioids (53.4%), hallucinogens (79.5%), methamphetamine (82.0%), or cocaine (90.5%).
Many people had multiple SUDs. Among adults with methamphetamine, cocaine, or hallucinogen use disorder, 48.2% to 72.0% had three or more SUDs. Nearly one-third of adults with opioid use disorder had three or more SUDs. Multiple SUDs were also common among adults with prescription stimulant, sedative, or tranquilizer use disorders.
Earlier substance use initiation was associated with more substance use and SUDs. Among adults who began using any substance before age 18, 16.9% reported using four or more substances in the past year, compared with 2.3% of those who began between ages 21 and 29. Having two or more SUDs was also more common among those who began before age 18 than among those who began at age 30 or older (9.7% compared with 0.9%). These findings show an association and do not establish that earlier use caused more SUDs.
The study highlights the varied patterns of polysubstance use disorders and the importance of prevention efforts during adolescence and young adulthood. It also points to the need for treatment and research that consider the range of substances a person may use and the possibility of more than one substance use disorder.
The Article
Han, B., Volkow, N. D., Jones, C. M., Dowell, D., Baldwin, G., Einstein, E. B., Subramaniam, G. A., Olsen, Y., Blanco, C., & Compton, W. M. (2026). Polysubstance use disorders among US adults. Molecular psychiatry, 31(9), 5303–5315. https://doi.org/10.1038/s41380-026-03618-z
