Alcohol use potentiates marijuana problem severity in young adult women.
BACKGROUND
Most young adult women who smoke marijuana also drink alcohol. Marijuana-related problems are associated with marijuana use frequency. We hypothesized that increased alcohol use frequency potentiates the association between frequency of marijuana use and marijuana-related problem severity.


METHODS
We recruited women aged 18 to 24 who smoked marijuana at least monthly and were not treatment seeking. Marijuana and alcohol use were measured using the timeline follow-back method. Problems associated with marijuana use were assessed using the Marijuana Problems Scale.


RESULTS
Participants (n = 332) averaged 20.5 ± 1.8 years of age, were 66.7% non-Hispanic White, and reported using marijuana on 51.5 ± 30.6 and alcohol on 18.9 ± 16.8 of the 90 previous days. Controlling for education, ethnicity, years of marijuana use, and other drug use, frequency of marijuana use (b = .22; p < .01) and frequency of alcohol use (b = 0.13; p < .05) had significant, positive effects on marijuana problem severity. In a separate multivariate model, the linear by linear interaction of marijuana by alcohol use frequency was significant (b = 0.18; p < .01), consistent with the hypothesis.


CONCLUSIONS
Concurrent alcohol use impacts the experience of negative consequences from marijuana use in a community sample of young women. Discussions of marijuana use in young adults should consider the possible potentiating effects of alcohol use.
General Medicine Research Unit, Butler Hospital, Providence, Rhode Island; Warren Alpert Medical School of Brown University, Providence, Rhode Island. Electronic address: Michael_Stein@brown.edu.
Michael D
MD
Stein
General Medicine Research Unit, Butler Hospital, Providence, Rhode Island.
Celeste M
CM
Caviness
General Medicine Research Unit, Butler Hospital, Providence, Rhode Island.
Bradley J
BJ
Anderson
D000293:Adolescent; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology*; D019973:Alcohol-Related Disorders / Q000453:epidemiology*; D000434:Alcoholic Beverages / Q000009:adverse effects; D003430:Cross-Sectional Studies; D005260:Female; D005544:Forecasting; D006801:Humans; D016015:Logistic Models; D002189:Marijuana Abuse / Q000453:epidemiology*; D008385:Marijuana Smoking / Q000453:epidemiology*; D011159:Population Surveillance; D012237:Rhode Island / Q000453:epidemiology; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult