How Prevalent Is Simultaneous Alcohol-Cannabis Use?

A new cross-sectional study from investigators at the National Institute on Drug Abuse (NIDA) found that 49.0% (95% CI, 47.8%-50.2%) of US adults who used both alcohol and cannabis in the past month reported using them simultaneously.¹ After weighting, that is about 14.1 million adults (95% CI, 13.6-14.7 million).

Simultaneous use was common across every factor the investigators examined. It was most common among adults with cannabis use disorder (CUD), peaking at 82.0% (95% CI, 75.9%-86.8%) among adults aged 50 years or older with CUD.

Earlier research compared simultaneous alcohol-cannabis use either with alcohol-only use or with mixed groups that included people using alcohol only, cannabis only, or neither. This study instead compared adults who use the 2 substances simultaneously with adults who use both but separately.

Study Design

The investigators analyzed data from 186,823 adults who completed the 2021-2024 National Surveys on Drug Use and Health (NSDUH). Simultaneous use was defined as using cannabis while drinking, or within a couple of hours of drinking, during the last drinking episode in the past month. Separate use was defined as past-month use of both alcohol and cannabis without simultaneous use.

Mental health and substance use disorders were assessed with DSM-5 criteria. These included past-year major depressive episode (MDE), alcohol use disorder, CUD, and other drug use disorders. The team found significant interactions between age and sex (P<.001) and between age and MDE (P=.02), so it stratified the analyses by age group: 18 to 29 years, 30 to 49 years, and 50 years or older. The analytic sample included 23,897 adults who reported past-month use of both substances.

Among all US adults, 51.6% used alcohol, 15.7% used cannabis, and 11.2% used both in the past month.

Key Findings

CUD was the strongest correlate of simultaneous use in every age group. Among adults with CUD, the adjusted prevalence of simultaneous use was 72.2% for those aged 18 to 29 years, 77.4% for those aged 30 to 49 years, and 82.0% for those aged 50 years or older. Among adults without CUD, the corresponding rates were 33.7%, 37.1%, and 39.3%. The adjusted prevalence ratios (APRs) were 2.14 (95% CI, 2.01-2.29), 2.09 (95% CI, 1.95-2.24), and 2.09 (95% CI, 1.85-2.35), respectively.

Lower educational attainment was also associated with simultaneous use. High school graduates had higher prevalence than college graduates in every age group, with APRs of 1.21 (95% CI, 1.12-1.32) for ages 18 to 29, 1.26 (95% CI, 1.10-1.38) for ages 30 to 49, and 1.23 (95% CI, 1.04-1.46) for ages 50 and older.

Sex and depression associations varied by age. Among adults aged 50 years or older, 51.4% of men reported simultaneous use compared with 39.0% of women (APR, 1.32; 95% CI, 1.20-1.45). Among those with MDE in this age group, 64.6% reported simultaneous use compared with 44.6% of those without MDE (APR, 1.45; 95% CI, 1.23-1.70). Smaller associations were observed among adults aged 30 to 49 years: the APR was 1.06 (95% CI, 1.01-1.11) for men and 1.14 (95% CI, 1.07-1.23) for MDE. Neither sex nor MDE was significantly associated with simultaneous use among adults aged 18 to 29 years.

Among young adults, simultaneous use was less prevalent among those aged 18 to 20 years than among those aged 26 to 29 years (46.1% vs 58.7%). Hispanic adults aged 18 to 49 years were also less likely to use the substances simultaneously than White adults.

Clinical Implications

The investigators wrote that simultaneous use may be a routine pattern for adults with CUD, especially older adults. They said this suggests simultaneous use has become normalized despite potential compounded risks, including impaired judgment, injury, and intoxication effects.² CUD is itself associated with adverse physical, cognitive, and psychosocial outcomes,³ and its prevalence and severity have been increasing.⁴

The study authors called for age-specific screening and intervention. They noted that older adults with CUD who drink may warrant increased clinical attention because simultaneous use is so common in this group and age-related risks are higher. They suggested that the different associations for sex and MDE across age groups may reflect age-specific mechanisms and motives for use.

The investigators also recommended risk-focused counseling, timely referrals, and impaired-driving education that addresses both alcohol- and cannabis-related impairment.

The authors noted the study may underestimate how common simultaneous use is, for 2 reasons. First, NSDUH excludes people experiencing unsheltered homelessness and people who are incarcerated. Second, the survey asked about cannabis use only during the most recent drinking episode, not during every drinking episode in the past month. The household screening response rate was 23.5%, and the adult interview response rate was 49.5%.

According to the authors, future research should examine how trends in simultaneous use relate to cannabis accessibility, social acceptance, legalization, and perceived benefits.

References

1. Han B, Hobin JA, Compton, WM, et al. Simultaneous cannabis and alcohol use from nationally representative data. JAMA Netw Open. 2026;9;(9):e2635815.

2. Lee CM, Calhoun BH, Abdallah DA, et al. Simultaneous alcohol and marijuana use among young adults: a scoping review of prevalence, patterns, psychosocial correlates, and consequences. Alcohol Res. 2022;42(1):08.

3. Connor JP, Stjepanović D, Le Foll B, et al. Cannabis use and cannabis use disorder. Nat Rev Dis Primers. 2021;7(1):16.

4. Han B, Compton WM, Hobin JA, Volkow ND. Trends in the prevalence and severity of alcohol and cannabis use disorders among US adults. JAMA Psychiatry. 2026;e262497. Online ahead of print.