Earlier First Use of Any Substance Predicted More Polysubstance Use Among 22,000 Mexican University Students
Among 22,224 Mexican university students, earlier initiation of alcohol, tobacco, or marijuana was significantly associated with current use of the same substance and with polysubstance use, with males far more likely to use marijuana.
Quick Facts
What This Study Found
In this large cross-sectional survey of first-year university students in Mexico City, most students initiated alcohol at age 15, tobacco at 15-16, and marijuana at 16-17.
Earlier initiation of alcohol and tobacco was associated with continued current use of those substances. Gender differences in alcohol and tobacco were small, but males were significantly more likely than females to use marijuana and to be polysubstance users.
Family substance use was associated with earlier onset across substances. Most importantly, there was a significant association between the earliest age of initiating any of the three substances and current polysubstance use, suggesting that early substance exposure, regardless of the specific substance, increases vulnerability to broader substance use patterns.
Key Numbers
22,224 students aged 17-20. Most common initiation ages: alcohol 15, tobacco 15-16, marijuana 16-17. Males significantly more likely to use marijuana and be polysubstance users. Family substance use predicted earlier onset. Earlier age of any substance initiation predicted polysubstance use.
How They Did This
Cross-sectional survey of 22,224 first-year university students in Mexico City in 2012. Chi-square tests and logistic regression examined associations between gender, age of onset, order of onset, family substance use, and current polysubstance use.
Why This Research Matters
Mexico has unique cultural factors around substance use (legal drinking age, attitudes toward marijuana, family dynamics) that influence initiation patterns. This large study demonstrates that the age-of-onset principle, earlier use predicting more problematic use patterns, holds across cultural contexts.
The Bigger Picture
Prevention science consistently identifies early substance initiation as a risk factor for later problems. This Mexican study confirms the pattern in a non-U.S. context and adds that family substance use is a key predictor of early onset, suggesting that family-based prevention programs could be particularly effective.
What This Study Doesn't Tell Us
Cross-sectional design captures only one time point. University students are not representative of all Mexican young people. Self-report may underestimate substance use. The study cannot determine whether early onset causes polysubstance use or whether both share common risk factors.
Questions This Raises
- ?Would delaying first substance use reduce polysubstance use later?
- ?Are family-based prevention programs more effective in Mexican cultural contexts?
- ?How do gender differences in marijuana use map onto Mexican cultural norms?
Trust & Context
- Key Stat:
- Earlier initiation of any substance predicted current polysubstance use among 22,224 students
- Evidence Grade:
- Moderate evidence from a very large cross-sectional survey, limited by self-report and cross-sectional design.
- Study Age:
- Published in 2017, using 2012 survey data from Mexico City.
- Original Title:
- Age of Onset, Current Use of Alcohol, Tobacco or Marijuana and Current Polysubstance Use Among Male and Female Mexican Students.
- Published In:
- Alcohol and alcoholism (Oxford, Oxfordshire), 52(5), 564-571 (2017)
- Authors:
- Strunin, Lee, Díaz-Martínez, Alejandro, Díaz-Martínez, L Rosa, Heeren, Timothy, Chen, Clara, Winter, Michael, Kuranz, Seth, Hernández-Ávila, Carlos A, Fernández-Varela, Héctor, Solís-Torres, Cuauhtémoc
- Database ID:
- RTHC-01530
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does using substances earlier make you more likely to develop problems?
This study found that earlier initiation of alcohol, tobacco, or marijuana was associated with both continued use and polysubstance use. While the cross-sectional design cannot prove causation, the finding is consistent with a large body of research linking early substance exposure to greater later risk.
Are there gender differences in marijuana use among Mexican youth?
Yes. Males were significantly more likely than females to use marijuana and to be polysubstance users. Gender differences for alcohol and tobacco were much smaller, suggesting cultural factors specifically discourage female marijuana use in this population.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01530APA
Strunin, Lee; Díaz-Martínez, Alejandro; Díaz-Martínez, L Rosa; Heeren, Timothy; Chen, Clara; Winter, Michael; Kuranz, Seth; Hernández-Ávila, Carlos A; Fernández-Varela, Héctor; Solís-Torres, Cuauhtémoc. (2017). Age of Onset, Current Use of Alcohol, Tobacco or Marijuana and Current Polysubstance Use Among Male and Female Mexican Students.. Alcohol and alcoholism (Oxford, Oxfordshire), 52(5), 564-571. https://doi.org/10.1093/alcalc/agx027
MLA
Strunin, Lee, et al. "Age of Onset, Current Use of Alcohol, Tobacco or Marijuana and Current Polysubstance Use Among Male and Female Mexican Students.." Alcohol and alcoholism (Oxford, 2017. https://doi.org/10.1093/alcalc/agx027
RethinkTHC
RethinkTHC Research Database. "Age of Onset, Current Use of Alcohol, Tobacco or Marijuana a..." RTHC-01530. Retrieved from https://rethinkthc.com/research/strunin-2017-age-of-onset-current
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.